Thursday, January 30, 2014

The Human's guide to being Human: How your cells work

Light energy from the Sun interacts with chlorophyll pigments found in plants to convert light energy in to usable chemical energy to power the plants' activities.  In humans, excess energy from food that is not used for daily energy needs is converted in to fat and stored for later use.  Approximately 85 million years ago, primates diverged from other mammals on the tree of life, eventually giving rise to what would become modern humans.  In 1928, Scottish scientist Alexander Fleming showed that if grown in the proper environment, the fungus Penicillium notatum would secrete a substance with antibiotic properties that he called Penicillin.

While there doesn't appear to be much similarity between the four examples listed in the above paragraph, they are all considered biological functions.  There are countless biological functions that occur within the human body on a daily basis, and when you expand that to include all of the biological functions from all life on the planet since life began, you would think it would be difficult to find something in common with all of them.  The thing is, it's actually not that difficult at all. Every biological function, whether it be from bacteria, insects, fish, birds, humans, or plants; or whether it takes place over the course of milliseconds, minutes, hours, or millions of years; is the product of a gene/environment interaction.  

Gene/environment interactions

There are many examples of how we have used the understanding of gene/environment interactions to better our lives.  In the example of penicillin, you may be surprised to learn that there is a completely logical reason that an antibiotic would be secreted by a fungus given the proper environmental conditions.  While the discovery of penicillin was accidental, the presence of an antibiotic can easily be explained by gene/environment interaction.

When Dr. Fleming picked up a petri dish that contained Staphylococcus aureus and had been contaminated with Penicillium notatum, he noticed that a mold had grown that killed the staphylococcus.  In an epic battle for supremacy, both the Staphylococcus aureus and Penicillium notatum were fighting for the limited food resources found in the petri dish.  However, when Penicillium notatum growth is limited by stress(In this case, competing for resources with another organism), it secretes an antibiotic that increases it's chance of survival and decreases the chance of it's competition's survival.  Using a finishing move contained within it's genome, the Penicillium dispensed of the Staphylococcus, won the battle, and became champion of that petri dish.

An infinite number of biological functions such as this take place every day.  As products of  gene/environment interactions, these functions are dependent on the presence of a gene and an environmental trigger that causes the gene to be expressed.  In the instance above, if Penicillium notatum didn't have the gene to secrete the antibiotic, or if the stress due to competition was not there, it would have never secreted it and the Staphylococcus would still be there.  Grown against a different foe with a more forgiving genome, or in an environment with ample food and space for both organisms, the staphylococcus may have stood a chance.  This is survival of the fittest, this is how natural selection, and biology as a whole, work.  In order to to understand biological functions and evolution, you first need to understand what genes are.

Genes and epigenetics

Genes, or DNA, are essentially a blueprint for you, a set of instructions contained within the nucleus of every one of your cells.  Your entire set of genes is referred to as your genome, and the vast majority of your genome is located within the nucleus of your cells and protected by a membrane.  A small portion of your genome is located within the mitochondria, or power plants of the cell, but those genes only code for parts found within the mitochondria.  Genes are often referred to as coding DNA because they are responsible for making proteins, and the part of your genome that consists of coding DNA is fixed from birth and identical in every cell of your body.  A perfect example of coding DNA in Penicillium notatum is the gene that makes pencillin, an antibiotic protein.  Another one found in humans is the gene that codes for insulin, a protein that helps the body store sugar.  The more complex the organism, the more complex the genome...or so we thought.

You may have heard that humans and chimpanzees are 98% similar from a genetic standpoint.  While it is true that our coding DNA is approximately 98% the same, the coding DNA is not the entire story.  Even a banana tree shares approximately 50% of it's coding DNA with humans.  This is because most living organisms are made up of the same types of cells with the same basic machinery in the form of organelles.

Organelles are the cell equivalent of organs, hence the name.  Interestingly enough, an organs' cells contain organelles that perform the function of that organ.  For example, the liver is a detox organ and the cells within the liver contain organelles that make detoxification enzymes, among other things.  These organelles are made in these cells because the DNA contains the instructions to make them and the environment the cell is in tells the cell to make these organelles.  This is how cells know what to do and why skin cells aren't actively making things like insulin, that set of instructions is read in the cells of the pancreas.  The environment communicates to the cell what to become, and the genes put that order in to action.

Taken a step further, your cells become what they become because the environment tells them what to become.  Many people don't realize that the blueprint in every one of your cells is identical.  So how does a skin cell become a skin cell and a liver cell become a liver cell if the instructions are the same?  In his book The Biology of Belief, Dr. Bruce Lipton discusses his work in cellular biology 50 years ago.  When he would take stem cells and put them in a petri dish under certain environmental conditions, they would become muscle cells.  The same stem cells placed in a different petri dish with different environmental conditions would become bone cells.  He explains that the environment interacts with the membrane of the cell and causes certain parts of the DNA to be read, or expressed, and other parts to be ignored.  This is called epigenetics and it is an aspect of genetics that was mostly ignored until recently.

Maybe that junk isn't actually junk

When scientists undertook the Human Genome Project, they expected to find at least 100,000 genes in humans given what they had found in other creatures.  Simple creatures such as C. elegans, a worm, has 20,000 coding genes, certainly a far more complex creature like humans will have more, right?  Not so much.  When the Human Genome Project was completed, it determined that humans had a total of between 20,000-30,000 genes.  What makes this even more shocking is that rice contains between 35,000-56,000 genes.  The problem isn't that we have so few genes, it's that a portion of the genome called "Junk DNA" that we disregarded happens to have a much larger effect on our complexity than the coding genes do.  In other words, what we called junk wasn't junk at all.

Since the "Junk DNA" didn't code for actual proteins, it sort of got thrown out with the trash, so to speak.  It certainly doesn't make sense that it's worthless considering it makes up about 98% of the genome.  However, since it didn't make anything quantifiable, researchers figured it was of minimal significance.  This portion of the genome is something we now call the epigenome, and it's significance is anything but minimal.  While the epigenome doesn't really make anything, it's significance is huge because it tells the coding genes what to do.  While the coding genes make insulin or organelles, the epigenome identifies the environmental condition and activates or suppresses all of the genes that are affected by that particular environmental condition.  If you look at the coding genes as the blueprint, the epigenome is the general contractor that reads the blueprint and puts it in to action. 

The epigenetics of animal development

From the day you are conceived, cells divide and replicate, passing along the genes that are contained within.  As you develop in to an embryo and beyond, HOX genes help guide your development by making HOX proteins that either repress or activate other genes.  In this way, the HOX proteins are a set of orders given out by the HOX genes that say, "Put the thorax here, put the eyes there, put ears here" and so on.  Embryonic development is a great example of epigenetics at play.  You may be surprised to learn that at one point you had a tail.  While you were but a wee embryo in your Mother's womb, you had a tail that eventually disappeared.  It disappeared because you are a human in a human uterus and human's don't have tails.  At some point during the developmental process, an environmental cue came that initiated apoptosis, or cell death, that lead to the removal of the tail.  The same thing happens with the spaces between your fingers and toes, the epigenome received a signal and the cells that made up the webbing between the hands and toes committed apoptosis and you were left with separate fingers and toes. In people with webbed hands or feet, or those born with a tail, the presence of these structures is an example of the epigenome not activating the proper sequence at the proper time. 

The power of the HOX genes also gives us an idea as to how all life on the planet is forever linked.  You may have noticed that all animals have a similar body plan.  While some may have wings, some paws, and others arms, the basic body plan is the same.  In the picture below, you can see how 2 seemingly uncommon creatures such as a fruit fly and a mouse share a similar blueprint for a similar overall body plan.

As you can see, there are similar structures and a similar basic body plan between a fruit fly and a mouse.  This is why we don't see animals that have 3 heads or an odd number of legs unless they are genetic defects.  There are only a few body plans that we see and all are similar because many of the instructions are similar because we share quite a few coding genes.  What makes this even more interesting, and the primary reason I used a fruit fly and a mouse, is that in 1994, research was done where the gene from a mouse that codes for the eye was placed in a fruit fly.  The result...the fruit fly grew a normal fruit fly eye.  This is because the genes are the same, it's not a difference in the specific gene, it's a difference in how and when the gene is activated that determines what type of eye is made, and that determination is made by the environment the cells are in.

Epigenetics and adaptation

So what does all of this have to do with being human and how we work?  Embryonic development is a great example of how epigenetics works, but epigenetics reaches well beyond embryonic development.  All biological functions are products of gene/environment interactions.   Your cells are attempting to put you in a position that is most advantageous to the environment you are in given what they can do, and when the environment remains consistent over time, patterns of gene expression are remembered and passed on to future cells.  Over time, your cells begin to "memorize" the environment by using epigenetic tags that get passed on to daughter cells, giving them a leg up.  When the environment changes for a significant amount of time, these tags are removed and different tags are laid down provided the environment remains constant for a time.

In much the same way, your genome has been shaped to make you better at things that your ancestors were good at.  While the epigenome can change in an individual, the coding genes do not, they are simply shaped in a population over the course of many generations as genes that put certain individuals at an advantage over others get passed on when people with those genes reproduce and have more children than those without the gene.  In addition, genes that put people at a disadvantage and also impact their ability to reproduce decrease or become removed from the population.  So in an individual, coding genes do not change they change in a population over long periods of time.

For example, the environment our ancestors were adapted to was low in food so being able to store fat efficiently is a beneficial trait to have.  Humans who were successful at passing on their genes to offspring were more likely to do this well so we are more likely to see people with genes that are efficient at storing fat.  In the same way, craving sugar and acting on that craving is something that is also advantageous when food can come and go in the blink of an eye, which is why most of us tend to crave fat, sugar, and carbohydrates.  

For most of our existence, food hasn't been that easy to come by.  Being able to store more energy for later use is in the best interest of humans because for most of our existence we have also needed to expend large amounts of energy to procure food.  Now, not so much.  When an organism's genes become adept at operating in a certain type of environment and that environment changes quickly, bad things can happen if there is a mismatch between what their genes are good at and what the environment requires for survival.  Since your genes are passed down to you by your parents, and theirs from their parents, your genes are well suited to an environment similar to theirs as well as their predecessors.  If your genes don't work well with the environment they are in because that environment changes on a dime, a mismatch occurs.  This mismatch between what our genes are good at and the environment they are currently in is likely the impetus for most of the chronic diseases we see today.

All is not lost, however.  The epigenome does allow us some flexibility to adapt to different environments, but there needs to be a willingness to do so in the face of such a drive to eat and be efficient with the amount of energy we use to get food.  In other words, personal responsibility is likely the first step until your body, and cells, adjust to the new environment.  Changing the environment you experience through diet and physical activity should begin to improve your health since it is the environment your genome was optimized for.  If your blueprint, or DNA, is fixed, why would things start to go bad if they've run smoothly for 50 or 60 years?  The likely answer lies with epigenetics.

Your genes are not your destiny

When people do genetic tests to find out if they have the gene or genes that are associated with a disease, what they are finding out is whether or not there is the possibility that a disease is in their future.  They are not finding out with 100% certainty that they will get a disease, that is dependent on if and/or when the gene(s) are expressed, and for how long.  There are people with genes associated with any number of diseases that may never get them.  Identical twins, while they contain the exact same DNA, often die of different causes.  That is because from the time they are born until the time they are married with children and have a career, their environments diverge from one another.  There are even identical twins where one is obese and the other is lean.  This is because the same blueprint has been put under different environmental conditions that have led to different patterns of gene expression.  The result...two different outcomes based on how genes are turned on and off by the lifestyle decisions each has made.

So why does the same plan lead to different outcomes based on specific aspects of the environment?  Why do biological functions occur?  And why may epigenetics help solve some of life's greatest questions?  The answers to these questions can be found by looking at evolution, but first we have to take a look at one more aspect of our genome that we didn't cover.  In the next blog we will go over the zoo of bacteria in your gut often referred to as your microbiome.

Next: Your microbiome

Monday, January 27, 2014

Health Research Recap (Week of January 21, 2013)

Women who are obese while pregnant have children who are more likely to become obese as they get older.  Until now science hasn't uncovered why this happens, but a recent study indicates that it may be due to improper wiring of the fetus' hypothalamus.  The hypothalamus is important in the regulation of appetite and metabolism, and it makes sense that improper development of the hypothalamus could contribute to the metabolic syndrome.  The problem with this study is that it was done in mice and the effect was produced by feeding the mice a high fat diet.  When using a high fat diet in mice, researchers almost always completely remove fiber from the diet which changes their microbiota and can have a pretty powerful effect on the development of their offspring.

Mother's diet isn't the only epigenetic factor than can affect a child's metabolism.  Another study in rats found that the health and diet of the father at time of conception also has an effect on offspring.  Male rats fed a high fat diet and who were diabetic and obese had female offspring with altered genetic expression in their fat tissue and pancreas that led to poorer blood glucose control.   Of course, this study suffers from the same drawback as the previous study with regard to the high fat diet, but both show how the health status of both parents can have a dramatic effect in offspring. 

A study looking at our good friend lipopolysaccharide(LPS) found that humans can smell immune system activation in other humans when they are injected with LPS.  The T-shirts of people injected with LPS were rated as smelling unhealthy compared to the T-shirts of people not injected with it.  Furthermore, those who had a bigger immune response were reported to have an unhealthier smell than those who had a smaller immune response.

A new study discusses hoe exposure to mildly colder temperatures can significantly impact fat loss.  According to a recent review, people adapt to cold temperatures (Approximately 60 degrees) by increasing brown fat, a type of fat that is metabolically active and helps control body temperature.  Another interesting point of view discussed in the study is that our continued focus on being comfortable may be a fairly strong factor leading to our higher rates of obesity.  Lowering the temperature in your house will not only save you money on your bills, it could also help you stave off obesity.  While there is an initial discomfort phase to the colder temperature, you will eventually adapt to the colder temperature over a couple of weeks.

In fish oil news, in addition to it's positive impact on inflammation and carbohydrate and lipid metabolism, the omega 3 fatty acid DHA appears to be protective of the liver and may help prevent or reverse fatty liver disease.  DHA improved liver function by reducing the damaging effects of inflammation and oxidative stress effect on the organ.

In another fish oil study, researchers found that high blood levels of the omega 3 fatty acids EPA and DHA were associated with larger brain volumes. Of particular interest is that those with higher levels of the fatty acids in their blood had a hippocampus that was 2.7% larger than those with lower blood levels.  The hippocampus plays an important role in memory and those with Alzheimer's experience a shrinking of the hypothalamus that likely contributes to the disease.

Finally, 2 studies identified depression as a common symptom in 2 separate autoimmune conditions.  One study found that those with severe rheumatoid arthritis are more likely to experience depression than previously thought.  The other study found that African American women who reported high levels of symptoms of depression were more likely to experience adult onset asthma than those who were not depressed.  While it certainly makes sense that someone who is sick will be depressed, a messed up gut microbiome is associated with both mood disorders and autoimmune diseases. 

Thursday, January 23, 2014

The Human's Guide to being Human: Science

From understanding that the Earth is round to the discovery of gravity, to the development of drugs that have increased our quality of life as well as our lifespan, science has served us well.  There is no doubt that science has opened up a world of knowledge that has bettered the lives of every human on the planet.  At the same time, it can lead us in the wrong direction when we don't understand it's strengths and weaknesses.  A better understanding of how science works can help you identify what science can or cannot say about health.

Science in it's infancy

While modern nutrition is relatively young, 200 or so years, humans have been observing the effects of nutrition and lifestyle on health for millenia.  In his book The Paleo Manifesto, John Durant does a great job of describing how religious texts such as the Torah, and the heavy focus on good hygiene, are essentially "scientific" observations of how infectious diseases can spread and rules on how to avoid spreading them.  To a person with no access to microscopes and no knowledge of what bacteria are, a bacterial infection would certainly seem like the wrath of God.  If you want to avoid feeling God's wrath, it's a good idea to wash your hands, avoid extramarital sexual encounters, avoid touching bodily fluids, and properly inspect your food.

Another early example of science includes the identification of scurvy, a disease of vitamin C deficiency, and the positive impact that citrus fruits had on curing people of the disease.  Scurvy was described around 400 BC, but it wasn't until vitamin C was identified in 1932 that we realized that scurvy is a disease of vitamin C deficiency.  Scurvy was common among sailors because fruits and vegetables wouldn't keep on long voyages and the grains and cured meats they would eat on these voyages were not significant sources of vitamin C.  This brings us to a pretty important point about what we currently know about nutrition; most of it is based on preventing deficiency, not optimizing health.

The RDAs are not optimal intake levels

Fast forward to today, and many people believe that the RDAs for vitamins and minerals are optimal dosages, but they're not.  The reason we have concrete dosages of vitamins and minerals is because getting less than these dosages leads to disease over time.  Health is not merely the absence of disease, many other factors go in to being healthy.  Having the energy to go about the day, being happy, and performing in a way that allows you to thrive rather than just survive are necessary components of being healthy.

While having concrete diseases of deficiency such as scurvy, rickets, and beriberi has helped us identify some critical nutrients that we need to survive, it certainly hasn't identified all of them.  Vitamin and mineral deficiencies lead to diseases of deficiency in the relative short term(3 years or less).  This doesn't mean that there aren't other nutrients that we need that keep us healthy and robust through old age or that prevent us from developing heart disease, depression, anxiety, or sleep disorders as we get older.  The direction that society has taken us with regard to science isn't to try and identify what causes these diseases, it has taken us in the direction of what medicine we can take to ameliorate the symptoms of them.  I don't know with 100% certainty what causes heart disease, but I do know that it's not a statin drug deficiency.  If it were, modern day hunter gatherer tribes would be dropping like flies of heart disease, yet it's relatively rare in their parts.

Deficiency or necessity due to diet?

Many of our nutritional problems may not even have to do with deficiency.  While I would consider the current Western diet to be pretty dismal with regard to it's nutritional value, there is also the possibility, and strong likelihood, that we are eating foods we shouldn't be eating.  A stark difference between our diet and the diet of modern day hunter gatherers is the abundance of processed food we consume.  While science gives us numbers as to what level of certain vitamins and minerals is necessary to prevent deficiency, these diseases of deficiency could actually be caused by a diet high in processed foods.  In other words, while it may be true that a 20 year old male needs 90mg of vitamin C per day to prevent deficiency, it could also be that this level of vitamin C is only necessary to prevent deficiency in a diet high in processed food since that is the type of diet that was studied when coming up with the RDA.  In fact, you don't need to go very far back in history to identify a situation where the consumption of processed food has lead to disease, only about 130 years.

The potential pitfalls of food processing

In the late 1800s, the disease beriberi was rampant in the Japanese navy.  Beriberi is a neurological condition that became prevalent in Japan as the processing of rice to increase shelf-life became prevalent.   The process of removing the husk from the rice, while extending the shelf-life, also had the unintended consequence of removing most of the thiamin.  At the time, scientists had only identified proteins, carbohydrates, fats, and salt as nutrients within food.  In 1898, Sir Frederick Hopkins hypothesized that there were other "accessory nutrients" within food that were essential for human health.  It turns out he was right, and those accessory nutrients eventually came to be called vitamins and minerals.  An interesting fact about thiamin is that it is used for carbohydrate metabolism, and feeding people the high carbohydrate starch found in rice without the thiamin needed to use it is likely what causes beriberi.  Thus, your thiamin needs are dictated by your carbohydrate consumption(1).

Most processed foods today are fortified with nutrients such as thiamin to replace some of the nutrients that could be potentially lost during processing.  Could the modern processing of food be doing the same thing with yet to be identified nutrients?  Who knows, but it is interesting that modern hunter gatherer cultures who don't consume processed foods don't tend to have many of the chronic diseases seen in Western cultures, at least until they begin consuming processed foods.

To be fair, there are may benefits to food processing, but you have to realize there will also be some tradeoffs.  In addition, there are other factors that play in to the diseases we see in Western civilization.  We are more sedentary and are exposed to far more chemicals than modern day hunter gatherer tribes.  We also experience dysfunctional sleeping patterns and are far more stressed than they are.  Nutrition is simply one piece of a very large puzzle that we are trying to put together to improve human health.  We like to think we have all of the answers, but the truth is we probably don't even have 10% of them because the questions are so complex and complex questions require complex answers.  However, you don't always need all of the answers to start making good decisions.

The problem with modern nutritional research

In a lot of situations, science hasn't provided us with the answers we need to make better choices.  However, we can use the science we have and try to fill in some of the holes with things we observe.  Like I said earlier, hard scientific certainty is very rare, especially within the nutritional and health sciences.  A lot of this has to do with the way we conduct and report scientific research.  All scientific discovery begins with an observation, like Isaac Newton's observation of an apple falling from a tree eventually leading to the discovery of gravity or scientists observing that citrus fruits ameliorated the symptoms of scurvy.  After these observations, scientists develop theories and run experiments to refine those theories until they come up with an answer.  This is how science works, but this is not how it is currently carried out, especially in nutritional science.  In the nutritional sciences, we begin and end at the observations and make recommendations based on those.  This is why we get so much conflicting research on what is healthy and also why it seems nutritional recommendations seem to change from week to week.

More trappings of observational data

One week coffee is great for you, the next week it is bad, and the week after that it is great for you again. The reason we see so much flip flopping on what is good for you is because the vast majority of the data we have is observational data.  We ask people what they've been eating and doing and we compare their health outcomes to their lifestyle habits to see what may or may not be healthy.  Like the apple falling from the tree, observational data is the observation that there is a relationship between two things, not that one causes the other.  We rely on this type of data for many reasons.  For one, we are looking at complex questions and to run experiments on these complex questions we would need to control variables other than the ones we are looking at to make sure they don't contribute to the results.  In the case of nutritional research, this means you would have to pull people out of their every day life, away from their job, away from their family, lock them in a metabolic ward, make sure they all sleep the same number of hours, get the same amount of exercise, experience the same levels of stress, and control their diet to the point that one group gets basically the exact same diet as the other group with the exception of the one variable you are measuring.  Who would sign up for that?

Another reason we rely on this data is that most health changes that occur with diet occur over a very long period of time.  So not only do you need to control their entire lifestyle, you have to do it over a period of 6-12 months or more for diseases that take a long time to develop such as cancer.  So, while we rely on this data out of necessity, we rely on data that really can't do anything other than tell us that people who eat X live longer or are healthier than people who eat Y.  Where we run in to a problem is when we have already given out advice without thorough experimentation first.  If you tell people that X is a healthy food, people who are interested in being healthy will be more likely to eat that food than people who are unhealthy.  People who are interested in being healthy also do other things that are healthy like exercise, get quality sleep, avoid smoking, and limit alcohol consumption.  If we don't control for these things, we cannot be 100% sure that this food is actually a healthy choice or if telling healthy people that this food is healthy makes them eat it.  This is exactly where we are right now, and is the reason why the science seems to flip flop, it's bad data and not valid for the way it is being used.

Looking at other areas of science

While this puts us in a tough spot, it doesn't put us in a helpless one.  The first thing we can do is look at how the human body works and identify areas where we may have gone wrong.  Understanding biology and evolution by natural selection can put us on the right path to discovering things that we are more suited to do and eat, and things that may not serve us so well.  Identifying the environment we evolved in can help us identify the environment we are most suited to thrive in, or at least identify aspects of the current environment that lead us astray.  When I refer to environment, I am referring to lifestyle factors that are necessary for optimal function, not merely your surroundings.  This does not mean that we cannot also thrive in another environment, it merely means you need to identify the optimal environment, start there, and work forward rather than just take what you read from observational research and assume it's optimal.

The next thing we can do is look at the lifestyle of groups of people who have better health outcomes than us.  If modern day hunter gatherers have a very low prevalence of the chronic diseases of aging and you want to avoid them, what are they doing differently?  Obviously they live a life more congruent to the environment we evolved in, what are the things they are doing and which of those things have a mechanism that can affect health.  They hunt and gather their food, but is it the process of hunting and gathering or is it that they are far less sedentary and consume far less food than us because they actually have to work to get it?  They also don't eat processed food and eat a nutrient dense, lower calorie diet that is very high in fibe(>100g/day).  Interestingly enough, we have studies that can shed some light on these traits, both by looking at what happens when hunter gatherers adopt a Western lifestyles as well as studies that look at how genes respond to diet and other lifestyle factors.

While I believe there is more than enough evidence out there to identify the key factors important to optimal health, if you are looking for every hole to be filled in for you, you are going to be very disappointed.  As I stated earlier, we really don't have concrete scientific evidence to hold your hand through the entire process.  This evidence likely will not come in your lifetime.  So does that mean you should just go with the flow and assume all observational data is pointing you in the right direction?  I think this is a mistake.  If we take the current science that we have, compare it to what we see with healthier groups of people, and scrutinize it from the perspective of what we know about human biology, I think we can get a basic framework of what is healthy and work forward from there.

In the next part of this series, we will take a look at how humans work, specifically with how our cells operate.

How our cells work

Monday, January 20, 2014

Health Research Recap (Week of 1/13/2014)

Those of you who think you may have Celiac disease but don't want to reintroduce gluten for weeks in order to damage your intestinal tissue enough to get a proper diagnosis via a biopsy may be in luck.  A new blood test is showing promise and can detect the disease after only 3 days of gluten exposure and results only took a day to obtain.  The test accurately predicted Celiac disease in people with the condition and did not show Celiac disease in people who do not have it.  However, the test needs to b researched on a larger scale before it will enter clinical use and a negative on the test does not necessarily mean someone is not sensitive to gluten, only that they do not have Celiac disease.  This test underscores how Celiac disease research really is in it's infancy, exposing a person to something that is thought to be severely damaging them in order to get a diagnosis is obviously not optimal, but it's all we have right now.

Researchers have found that humans and other primates burn 50% fewer calories than other mammals.  This likely accounts for the slower development seen in primates as compared to other mammals.  When humans are born, they are born fragile, take a year or more to be able to walk clumsily, and take upwards of 17-18 years to fully mature.  Compare this to a deer that takes minutes to stand and walk and is fully mature by age 5.  Of the primates, humans develop the slowest and our slow development is thought to be why our brains are more advanced and why we live to older ages than other primates.  Another interesting finding of this study is that primates in captivity expend the same number of calories as their wild counterparts.  This supports an earlier study showing modern human hunter gatherers burn basically the same number of calories as their more sedentary Western counterparts.  In other words, your 3 hours of exercise each week is having little effect on how much energy you are burning.

A study looking at both increased physical activity as well as decreased sedentary time found that this two pronged approach led to improved ratings of health and quality of life.  The study found that people who more active rated their health and quality of life as better than people who were less active.  In addition, those who reported sitting more rated their health and quality of life lower than those who sat less.  The results of the study underscore the importance of dealing with physical activity time(Often thought of as exercise) and sedentary time as two separate variables.  In other words, exercising is important, but sitting less throughout the day is equally important and long periods of sitting cannot be counteracted by simply exercising a little more.  Even just breaking up periods of sitting with getting up every once in a while can be a successful strategy to reduce sitting time.

Another study found that sitting for more than 11 hours a day increased all cause mortality by 12% in postmenopausal women. In addition, sitting for that long also increased the odds of dying from coronary heart disease, cancer, and cardiovascular disease by 27%, 21%, and 13%.  Sitting for long periods of time causes many negative physiological changes including reduced muscle mass as well as altered metabolism through changes in genetic expression, particularly with fat metabolism.

In obesity news, drinking diet soda causes overweight and obese people to consume more calories from food throughout the day.  Nothing new here, just phrased differently than this one, which basically says if you're going to drink soda it doesn't matter if you drink diet or sugar sweetened soda.  How about you just don't drink soda?

Aerobic exercise has been shown to protect against diabetes, and strength training has been shown to help manage Type 2 diabetes, the effects of strength training in preventing Type 2 diabetes in women have not been sufficiently studied.  A new study fund that strength training is beneficial in reducing the risk of type 2 diabetes in women and that a combination of strength training as well as lower intensity modalities such as aerobic training and yoga yielded the best results.

A new study in Type 2 diabetes identifies changes in "junk" DNA as being a causative factor in the disease.  The researchers found that sections of the "junk" DNA may be causing the genes responsible for producing insulin to be expressed improperly.  For years researchers threw away the "junk" DNA because they thought it was just that, junk.  This is because this part of the DNA does not code for proteins.  However, this area is now thought to be pivotal in diseases like cancer and Type 2 diabetes because this section of DNA is responsible for the way coding DNA is expressed.  While I believe these researchers are right for looking in this area, they are looking for genetic variants that make someone more likely to develop Type 2 diabetes.  While I believe this is worthwhile, I feel we should be looking at lifestyle factors that contribute to these changes so we can avoid them.  If genetic variants were the end all be all people would not develop Type 2 diabetes, they would be born with it.  "Junk" DNA is now known as the epigenome which can be changed via lifestyle, which I will discuss in one of my upcoming blogs in the series The human's guide to being human.

In a perfect segue from diabetes to gut bugs, a French/Swedish team of researchers has undercovered a way by which dietary fiber prevents obesity and diabetes.  It turns out the bacteria in your gut ferment these fibers in to the short-chained fatty acids propionate and butyrate that act on the intestine and causes it to produce glucose.  When glucose is produced in this way, even in the presence of a high fat/high sugar diet, a range of protective benefits occur via the brain.  This includes reduced hunger, increased energy expenditure, and reduced glucose output by the liver.  When mice who lack the ability to synthesize glucose in the intestine from these products of microbial fermentation are fed fiber, these protective benefits do not occur.  This points to fiber intake as being a very important factor in preventing the metabolic syndrome, and illustrates another way that your gut bugs are important to your health.

Yet another study looking at gut bugs found that high intakes of prebiotic fiber activate a receptor in the gut that dampens inflammation.  When your gut bugs ferment fiber, they produce a short chained fatty acid called butyrate.  When butyrate is produced in sufficient quantities, it activates a receptor in immune cells that reside in the colon, causing them to produce anti-inflammatory molecules and also signal other cells of the immune system to do the same.  This receptor is also found in fat cells and provides a protective benefit to the heart, but so far butyrate has only been shown to activate this receptor in the digestive tract.  Niacin has been shown to activate this receptor throughout the body, including the digestive tract, and can produce the same effect as butyrate in cells found there, even in a low fiber diet.

Looks like scientists have found a way to make fiber even better.  By creating a new "designer" fiber, researchers have come upon a way to slow the fermentation of fiber, allowing it to reach the more distal colon where common colon problems, including colon cancer and diverticulitis, often occur.  I could see this as a way to quickly turn around problems in the descending colon before they become bad, but this won't be a replacement for a high fiber diet.  It is also unlikely to be useful if your goal is to eat a mostly processed food diet and supplement with a little "designer" fiber.

A study looking at the benefits of probiotic use in infants has provided support for the use of a lactobacillus strain in infant GI disorders.  The study found that infants who were fed the probiotic strain L. reuteri DSM 17938 for their first 3 months of life had shorter bouts of crying, fewer regurgitations, and were constipated less than children not given the probiotic.  In addition, there was an approximate $120 average savings per family who used the probiotic over the 90 days due to reduced hospital visits.  There was an additional $140 savings to the community as well.

Finally...Jeff Leach, who is part of the Human Gut Project, is going to perform some pretty interesting self experimentation in the upcoming year.  He is going to follow several different diets for weeks and test have his gut microbiome to see how, and how quickly, his gut bugs change under different dietary conditions.  He is also going to live as a hunter gatherer and see how his environment affects his gut bugs as well.  I can;t wait to follow this one.  Here's a great write up in Science on the Human Gut Project.

Thursday, January 16, 2014

The Human's Guide to being Human: Introduction

Why do lifestyle choices have such a big impact on our health?  Why do we live for 60 years in relatively good health just to come down with Cancer, Type 2 Diabetes, and/or Heart Disease towards the end?  Is there a way to help us make better lifestyle choices that can help prevent the chronic diseases of aging?  These are all good questions that, if answered, can greatly improve our quality of life and put a significant dent in our annual healthcare spending.  Unfortunately, the path to answering these questions and unlocking the keys to human health is paved with special interests and misinformation.  The purpose of this blog series is to help you better understand human health and the things you can do to optimize it.

Our understanding of human biology has greatly improved over the last few decades as science has shed some light on what makes us tick.  Early on in our understanding of human biology, we believed that our genes were our destiny.  If you were born with a gene that made you susceptible to a certain disease, you would eventually develop that disease and die.  Now that we have advanced our knowledge beyond that rudimentary understanding of how genes work, we realize that this is not the case.  Disease and poor health are not the product of bad genes and poor luck, they are a product of poor gene/environment interactions, particularly if you make it in to adulthood in relatively good shape.  Certainly there are examples of diseases that are simply due to being dealt a poor hand in life, but these diseases make up less than 2% of the diseases we see and do not include Type 2 Diabetes, Cardiovascular Disease, and most types of Cancer.

In addition, diseases that are strictly genetic in nature will present themselves throughout life, mostly from the start.  The coding genes you were born with aren't written in pencil, they are written in permanent marker.  That is not to say that they can't be changed, but if they are changed they are changed via radiation or some other environmental factor which is still a product of gene/environment interaction

While lifestyle has a tremendous impact on your health because it dictates how your genes and environment interact, we cannot fall in to the trap that there is a single, optimal environment for all of us.  One of the biggest trends that is having a dramatic impact on the health of thousands is the trend towards a Paleo lifestyle.  Proponents of this lifestyle believe that "regressing" their lifestyle back to simulate the lifestyle of Paleolithic hunter-gatherers will allow them to experience optimal lifelong health and wellness.  However, this is not necessarily the case.  While I believe that looking at our current health issues from an evolutionary perspective will certainly help improve many of the chronic diseases of aging we currently see today, many people are coming to the illogical conclusion that living a hunter-gatherer lifestyle will guarantee them optimal health well in to their 90s.  Not so much.  Evolutionary success isn't dependent on whether or not we can sprint fast when we are 60, or whether or not we have perfect eyesight, it is dependent on successfully passing your genes on to the next generation so that they can do the same.  When you look at humans, however, one can infer from the last part of that statement that longevity is something that is necessary for success of the species.

While proponents of the Paleo diet are making an illogical assumption that lifelong health is attainable by regressing back to the Paleolithic era, opponents also make illogical assumptions.  Many assume that we are merely meant to pass our genes on and then from that point on it's borrowed time.  The problem with this line of thinking is that one of the things that makes us uniquely human is that we develop at a much slower rate than other animals.  While most other animals are capable of providing themselves with enough resources for success within a year or 2 after being born, human children are unable to do so until they are 17 or 18 years old.  If we were meant to only have children and die, is evolutionary success attainable if our children die before they can attain enough resources on their own to reproduce and pass on their genes?  I think not. 

While science has brought us to a greater understanding of human biology and evolution, it is also holding us back.  Nutrition is one of the major environmental factors that helps influence our health by manipulating how our genes are expressed.  Of all of the environmental factors that we can manipulate to alter the way our genes work, nutrition is certainly up there.  People often like to look at health from a percentage of importance perspective and give diet upwards of 80-90% of the weight, but you can't fall in to this trap.  There are countless environmental conditions that impact health and are REQUIRED for good health.  In other words, I wouldn't look at it like, "Health is 80% diet", I would look at it like, "Proper nutrition, regular physical activity, good sleep, and stress management are all requirements for good health".

However, our understanding of nutrition is poor because most of the scientific data we have is of poor quality.  In addition, special interests run, and ruin, nutritional research.  All forms of research are expensive, and companies in the food industry have a financial interest in showing that the food-like substances that they produce are perfectly healthy for you to consume, even if they're not.  There is, however, no immediate financial interest to an organization to run a study to determine what foods are best for us to eat or which lifestyle habits will keep us healthy.  In the first part of this blog series, we will go over the ways that science is manipulated and reported that can direct us to make poor nutritional choices.

In the second section, we will go over the way your cells work.  A healthy person is made up of healthy cells, and a better understanding of how our cells work can help us make better decisions with what we eat and the lifestyle activities we choose to partake in.  You don't need to understand cellular biology at a college level to grasp these concepts, but you should understand the basic, general concepts of how our cells work and interact with one another.  Of chief importance is the way our genes interact with the environment to help our cells make us become who we become.  Armed with the knowledge of how this works, you can begin to see how lifestyle impacts your overall health.

In the third section we will go over the hottest topic in nutritional research, and possibly even all biological research right now, the gut and the more than 100 trillion inhabitants found within it.  The zoo of bacteria found in your gut, also called the microbiome, perform many tasks that are critical to human health that we cannot do without them.  Once you understand how evolution and competition via natural selection work, you can see how your lifestyle choices not only directly affect you but also how they affect your microbiome and how that, in turn, indirectly affects your health.  Many people take prebiotics and probiotics or eat fermented foods without knowing why they are doing it, this section will shed some light on why they may improve health.

In the fourth section, we will go over evolution and how it pertains to human health.  Evolution is a concept that most people have heard about, but few people have a thorough grasp of.  Again, you don't need a college level course on evolution to understand why it's important and how it impacts your health.  Just understanding the basic process and how it got you where you are can teach you more than enough about how to be healthy and why people get sick.  Evolution also shows us how intimately linked all life on Earth is, and why we use animal research to help guide us in the right direction for human research.  Another bonus with using an evolutionary approach to health is that it can help drive research when there is conflict between different scientific studies.  Evolution is the guiding tenet of biology, ignoring evolution when looking at human health is like trying to fly a plane without the principles of flight, it just doesn't work.

In the final section we will look at the research and how applying some of the concepts in the earlier sections can greatly improve human health.  Looking deep within our past can shed some light on where we may have went wrong from a health perspective.  Using what has happened in the past and comparing that to what we are now seeing in health research is a potent 1-2 punch that could greatly improve our knowledge of what is healthy.  In addition, looking at modern hunter gatherer societies and how their diet and daily activities lead to different health outcomes than the ones we see in Western society can provide confirmation that our health would be vastly different if we provided an environment better matched to our genes.  While most people point out that we experience the chronic diseases of aging because we live longer, that doesn't explain why these diseases are relatively rare in modern day hunter gatherer tribes.

At the conclusion of this blog series I hope that all of you have a firmer grasp on the way we operate.  The purpose of this blog series is to help you better understand the complexities of human biology in a way that is easy to understand.  Depending on how many people read this series, I would like to add on to it.  In the future I would like to expand this series to include sections on stress, metabolism, and proper movement.  I feel these topics can be covered in a way that is easy to understand and that will provide tons of applicable knowledge that can help people with issues such as joint and back pain and that could improve weight loss and overall quality of life.  So please "Like" or "Share" this series through Google+ or Facebook.  Let's get to it!  Next Thursday we cover science.

Human's guide: Science

Monday, January 13, 2014

Health Research Recap (Week of 1/6/2013)

What better way to get back in to the Health Research Recap swing of things than with a study on gut bugs?  You may recall a study we looked at a few weeks ago that showed that those raised in households with dogs are less likely to develop asthma than households without dogs.  Another study in mice looking at fiber intake showed that the inflammatory response seen in asthma is dampened in mice who consumed higher fiber diets via fermentation of these fibers by gut bacteria.  These are fairly exciting results as the parts of the immune system studied are identical in mice and humans.  This doesn't mean that the effect will be identical in humans, but is eating more vegetables really that bad?

Add another study to the pile of evidence that Type 2 diabetes is an inflammatory disease.  Researchers working with mice looked to identify the mechanism by which pancreatic beta cells are destroyed during Type 2 diabetes.  They found that mice in the early stages of Type 2 diabetes have a high level of immune cells called macrophages that begin to attack pancreatic tissue and secrete inflammatory cytokines that destroy the beta cells that are responsible for secretion of insulin.  I wrote an earlier blog on how macrophages contribute to Type 2 diabetes and contribute to an increase in the liver's production of glucose.  It almost seems like the macrophages are on some form of sugar/crack binge as they are activated, trying to bogart all of the glucose and destroying anything that can get in the way.  Obviously I'm joking, but I think it's a pretty good metaphor for what we see in people who get their fix from high sugar consumption.

If you needed another reason to quit smoking, add better sleep to the list.  A study looking at the effects of cigarette smoke exposure in mice found that both long and short term smoking led to changes in gene expression that negatively affected the circadian clock in both the lungs and the brain.  Decreases in expression of these same genes is seen in humans with COPD, adding further smoke to the fire.  One question that hasn't been answered is which brand of cigarettes mice prefer.  If they're anything like Doctors in the 40s and 50s, my guess is Camels.

Another study looking at sleep found that one night of sleep deprivation increased blood levels of 2 molecules associated with brain damage the following morning.  While this certainly does not mean that sleep loss causes brain damage, it is likely that sleep loss is a neurodegenerative process that can negatively impact brain function over time.  This backs up other evidence as to the importance of sleep for optimal brain function, but doesn't really give us anything on how poor sleep quality or lower amounts of sleep affect brain function.

Looking at the psychological aspects of eating, a paper by marketing researchers at Vanderbilt indicates that people may prefer supersizing, even if the foods that are being supersized are healthy.  Apparently, tapping in to a person's inner tightwad may be a potential strategy to get people to eat healthier.  The primary hang up?  Foods that are supersizeable are that way because of subsidies that make junk food cheap to make.  Unless the subsidies are redirected to healthier choices it's just not a strategy I see McDonalds undertaking, at least if they care to turn a profit.

Higher levels of Vitamin D3 during pregnancy are associated with stronger children with greater muscle mass at age 4.  The study looked at the Vitamin D3 status of women in the later stages of pregnancy and compared those numbers to their offspring's grip strength and muscle mass at age 4.  This is yet another study that shows how important the nutritional status of the mother while pregnant can have a significant impact on the future health of the unborn fetus.

*Sigh*, they never learn.  Researchers looking at cholesterol numbers and the risk of Alzheimer's disease found that elevated "bad" cholesterol and low "good" cholesterol may have the same negative effect on the brain as they do on the cardiovascular system.  The researchers found that people with higher LDL cholesterol and lower HDL cholesterol were more likely to have higher levels of beta amyloid plaques than people with healthy cholesterol numbers.  I don't feel I have to go over the fact that our knowledge of cholesterol numbers is archaic and incomplete to say the least, but I do feel the need to point out the logical fallacy these researchers are making.  It could be that high LDL cholesterol and low HDL cholesterol cause damage to the brain, but it is equally as likely that whatever causes these cholesterol numbers to be off is actually what is causing the amyloid beta plaque accumulation.  In other words, taking a drug to artificially lower your LDL cholesterol will only mask the symptoms, the medical equivalent of putting electrical tape over your illuminated "check engine" light.  This notion jibes with some of the research that statins may not be all that good for your memory.  While the evidence is split on this, even if memory problems are only a potential side effect I'll err on the side of caution.  I like my brain the way it is.

Playing high school sports is not only good for your health in high school, it translates in to better health in to later adulthood.  Researchers found that 78 year old men who played high school sports visited the doctor's office fewer times per year than those that didn't.  What is really cool about this study is that all of the men who were studied were healthy as young men as they had to pass a physical to enter the military.  Those that played a high school sport reported visiting the doctor fewer times per year and were more likely to still be active than those that didn't.

Breastfeeding is often discussed as important for the health of baby, but a new piece of observational research indicates it has benefits to mom also.  The study looked at women who had one or more children and found that those who breastfed were half as likely to develop rheumatoid arthritis as those that didn't.  As always, you kind of have to take the observational data with a grain of salt.  Women who are in to health are more likely to breastfeed and also to practice other healthy behaviors, but the results are interesting, nonetheless.

Starting Thursday I will be posting my blog series on human health and how lifestyle affects it.  As of now it's a 5 part series so I'll be releasing that for the next 5 Thursdays while doing the Health Research Recap on Mondays. 

Thursday, January 9, 2014

Meat-based diet and inflammation? Makes sense from an evolutionary perspective

A new study in the journal Nature set the Paleo blogosphere ablaze last month.  This study looked at the effect of diet on changes in gut bacteria and was discussed in my Health Research Recap found here.  I went over how I agree that a diet that focuses on meat is likely not the best choice if your goal is to be healthy.  In this blog I am going to expand on this topic using the evolutionary template to theorize why this happens.

One of the more interesting aspects of the study in question, found here, is that gut bacteria switched rapidly when going to the extremes of diet.  In my opinion, this is a testament to how important a diverse array of bacteria in the gut is to maintaining metabolic flexibility.  Humans can thrive on a wide array of diets and the ability of bacteria in the gut to respond to quick changes in the availability of food from the environment is what makes us metabolically flexible.  From an evolutionary perspective this makes sense because once our ancestors left Africa, the most likely to survive would have been the ancestors who could adapt to changes in the types of food that were available due to seasonal changes in the climate.

As Summer leads to Fall and Fall leads to Winter, the availability of fruit and other foods that were preferred by our ancestors who remained in Africa would not have been available in more seasonal climates during a time when you couldn't just order takeout.  To adapt, they likely needed to consume fallback foods that were available in a wintery climate during that time of year.  This would include meats and root vegetables whose availability would change less with the seasons.  With this change from a diet high in fruits and vegetables to one with a proportionally smaller amount of these foods and a higher proportion of animal flesh, you are changing the substrate that the bacteria in your gut can ferment from mostly fermentable carbohydrates to amino acids.  This, in turn, should change the proportion of bacteria in the gut, favoring the types of gut bacteria that ferment amino acids and scaling back the type that ferment carbohydrates.  Could there be some evolutionary benefit for this switch?  I think so.

As the diversity of available food reduces during the winter time, there would be a benefit to extracting more energy out of that food.  Most people believe that carbohydrates and protein contain the same amount of calories per gram at 4 calories, but this is not true.  In a bomb calorimeter, carbohydrates average 4.2 calories of energy per gram while proteins average 5.65 calories per gram.  Some of this increased energy content is due to the nitrogen content of protein, which humans don't use for energy.  Even if half of the extra energy is from nitrogen, that still leaves an extra 17% more energy in protein per gram than carbohydrates.  This is huge when food becomes scarce.  One of the first things one notices as they implement a low carbohydrate diet is constipation.  Maybe this delay in food transit through the digestive tract allows us to absorb more of that energy or it gives bacteria in the colon more time to ferment amino acids that make it there, providing more energy than we can extract on our own.

On top of the potential for extra extractable energy contained in protein, there is the inflammation associated with the bacteria identified in the study.  While our current food environment makes this a bad thing, in the face of food scarcity, this inflammation may be beneficial.  Inflammation is associated with insulin resistance and obesity, two conditions associated with the theoretical thrifty genotype that is more likely to experience these conditions.  Perhaps the inflammation associated with this change in gut bacteria is expressing these thrifty genes to a greater extent and allowing the host to get by with less food.  In other words, the inflammation these types of bacteria create functions as a signaling molecule to the host, letting their body know that it's time to be thrifty and more efficient with cellular energy consumption and storage as the types of available food declines.  This inflammation coupled with moderate to high carbohydrate consumption could improve fat stores during the end of fall as the wintery season approaches and begins to take hold.

We can compare this to what we see today in Type 2 diabetes.  In Type 2 diabetes, people become insulin resistant which causes their blood glucose to rise.  What we see in people with Type 2 diabetes is an eventual spilling of fatty acids in to the blood stream during this process.  This is due to the extremely high levels of blood glucose we are able to attain today with the types of foods that are available in addition to the fact that we are able to exceed our ability to store fat.  Who knows how this process would play out as it did back when our ancestors were moving out of Africa searching for food and being on the low end of their fat storage capabilities.  If it plays out in a similar fashion to the beginning stages of Type 2 diabetes, it is likely that they experienced an enhanced ability to accumulate body fat, a beneficial effect when going in to a season where carbohydrates won't be available.  What we are now seeing with Type 2 diabetes could potentially be the consequences of our past environment selecting traits that were advantageous at the time that are now no longer advantageous.  A recent study in the journal Nature indicates that this may be so.

The study looked at people of Latin American descent and identified a gene associated with Type 2 diabetes that is very prevalent in that population(approximately 50%) called SLC16A11.  This genetic variant alters fat metabolism and causes an increase in cellular fat levels.  People with one copy of this variant are 25% more likely to develop Type 2 diabetes while people with two copies are 50% more likely to develop it when compared to people without this variant.  All of this science mumbo jumbo is nice, but the science behind this pales in comparison to where this gene likely came from; Neanderthals.

This is extremely interesting because Neanderthals left Africa much earlier than we did and those that were more adapted to efficiently storing fat were far more likely to be successful in environments where food sources were seasonal.  Much of the Neanderthal anatomy was suited to cold weather because they had experienced it for millenia before we made our way out of Africa, it only makes sense that their physiology would be optimized for that environment as well.  If this is one of the thrifty genes, perhaps as their diet changed moving in to winter, so did their gut bacteria,.  This, in turn, may have increased expression of this gene, as well as others, which would make them more "thrifty" and, thus, better adapted to their environment via improved fat storage.

Another piece of potential "evidence" comes from those undertaking low carbohydrate diets.  It is common knowledge that low carbohydrate diets aren't typically effective for fat loss when protein intake is high.  The conventional thinking is that this is due to protein causing insulin secretion as well as the ability of certain amino acids to convert to glucose and raise blood glucose levels.  However, it is interesting that high protein intake in the face of low fiber intake causes such a dramatic shift in the composition of gut bacteria given that the vast majority of  low carbohydrate diets tend to be high in protein and low in fiber(Atkins diet).  While a much more gradual shift in the availability of foods is more likely, the ability to adapt quickly would be highly beneficial.

Overall, I think there is a lot of evidence that supports the notion that a diet that is primarily meat, potentially even grass-fed beef, may cause inflammation due to increased protein consumption changing the landscape of the host's gut bacteria.  There appears to be a large benefit to the host through this process.  You have to be careful with what you can generalize this to, however.  I don't believe this indicates that moderate meat consumption is bad, and the ratio of meat to fiber is probably a much bigger determinant of this effect as is the ability of the host to digest protein.  Protein consumption, per se, is not the problem.  The ability of undigested protein to make it's way to the colon where the types of gut bacteria that can ferment amino acids can act on it is the chief concern.  In the absence of high carbohydrate consumption, this inflammation may even be benign.

Preliminary results from the Human Gut Project indicate that people who consume a Paleo diet tend to have higher levels of bacteria that are associated with inflammation, but most of these people have fewer complaints related to inflammatory conditions.  I do think this points to a more moderate approach to meat consumption than most people undertaking a Paleo diet implement for the simple fact that most overconsume protein from meat and nuts.  However, this doesn't vindicate the consumption of protein from vegetable sources.  In fact, given that a lot of these proteins are difficult for humans to digest, especially grains as well as soy and other legumes, they could potentially amplify this effect, especially when fiber intake is low.  Since vegans often rely on protein powders rather than whole food sources to fulfill their protein needs, they are essentially consuming high doses of protein that is more likely to become problematic, even at lower total protein intakes  Therefore, consuming concentrated sources of harder to digest proteins is not a great idea if you are looking to control inflammation, especially if you are also consuming large amounts of carbohydrates as is typical of the vegan diet.

Monday, January 6, 2014

Book Review: Last Ape Standing

One topic that is both controversial as well as difficult to write about is human evolution.  For some reason, some people don't feel evolution pertains to us.  In fact, as recently as 2012, less than half of the United States believed that humans evolved either with the assistance of, or in the absence of, a God.  This is fairly troubling given the number of scientific discoveries and medical therapies that are used by everyone today that would not be possible without the study of human evolution.  Evolution is the central tenet behind biology, so much so that trying to "do" biology without evolution would be like trying to fly a plane without the principles of flight.  Medicine is not possible without biology, so one can safely conclude that medicine is not possible without evolution.  The reason that human evolution is so controversial, and also why it is so difficult to discuss, is that it is far from settled.  What Chip Walter does with his book Last Ape Standing is discuss the available evidence and form a story for how we got to where we are today.  He does a fantastic job of doing this.

From the beginning of the book, Chip makes you feel quite comfortable with his knowledge base on the topic.  He fills you in on how evolution works through natural selection and why the argument that evolution is a random event therefore humans cannot be involved in the process is flat out wrong.  What you've become is far from a mistake, you are the product of nearly 4 billion years of the environment on Earth engineering you to become something that can succeed at life in that environment by being born, maturing to the point you can pass on the genes that were passed on to you by your parents, and the same cycle repeating for your offspring.  In fact, humans downright thrive on a planet where most organisms just struggle to stay alive long enough to pass on their genes.  Who you are now is no more of a mistake than a car having 4 wheels or a plane having 2 wings.  Sure, there is the potential that there is a better way, but we don't have it yet.  A great example of this is similarities in body plans between water dwelling mammals and fish.

If you compare a land mammal to a fish, there is not a clear similarity between their body plan.  Sure, both have 2 eyes, 1 mouth, and a few other similar characteristics, there are quite a few differences.  Probably the most obvious is that fish have fins, flippers, and tails while land mammals do not.  However, mammals that live in the ocean tend to have all 3 or at least 2.  This is because to be successful in the water, one would require these traits to be successful.  This is no random mistake, if you don't have a way to move to get food which helps you make it to your reproductive years to pass on your genetic material, you're a goner.

With that basic understanding of evolution, Chip brings you on a journey as to why we are the most successful primate, and why our other human cousins are no longer here.  He takes you on a ride to explore the human family tree and the traits of those who came before us and some who were around alongside us for a while.  The fact that we are the last one standing is a testimony to not only those traits that solely belong to us, but the traits that our forebears passed on that make us better adapted to the environment we are in.  Sure, our brains are far more advanced than any other that came before it, but it would not have been possible to shape that brain had we not come up off all fours, moved from the trees to the savanna, began scavenging food sources high in Omega 3 fatty acids, and eventually began cooking our food.

Many factors apparently played out to make the human brain develop the way it has.  Fasting causes cell growth to slow down in every way except for brain cell growth, which increases in times of food scarcity.  Our brains are extremely rich in the omega 3 fatty acid DHA that can be found in fish and organ meats, but is not efficiently attained from plant sources.  Finally, cooking food makes many nutrients available that we were unable to get to before we cooked food, particularly in meat.  Cooking food gives our digestive systems a break and digestion, particularly in other primates that need to break down fibers that we can't, is an expensive process from an energy standpoint.  When resources don't need to be directed to digestion, they can be directed to brain development, another expensive process.  This is called the expensive tissue hypothesis and is covered in the book.

Another important concept to human development covered in the book is called neoteny. 
Compared to other primates, we are born much sooner, develop much slower, and as a result, develop bigger and better brains.  While humans and chimpanzees have nearly identical coding genes, our genes are expressed differently.  Put another way, it's not the genes, it's how they are used.  And how genes are used is dictated by the environment the organism is in.  This is what epigenetics and evolution is all about.  Chip gives an excellent example of this when he discusses a chance encounter by an anthropologist and a tribesmen who believed a herd of water buffalo in the distance were a type of insect.  Since this tribesman's village was in the dense jungle, he never developed the ability to comprehend long distances such as those he was experiencing on the wide open plain they were standing.  Since the tribesman was never exposed to that type of environment, the genes that would allow him to comprehend that environment in his brain were never expressed, so he never developed teh abiity to process that type of information.

In a similar light, Chip theorizes that one of the reasons we are still here is possibly because we left Africa when the time was right.  Other human species left Africa much earlier than us, but because they were unable to successfully adapt to their environment, or because they adapted to that environment and the environment quickly changed, we took over.  Neanderthals left Africa long before us and became adapted to much colder climates than we were at the time.  Theoretically, they should have been more suited to the climate and environment of the more northern latitudes that we began creeping in to as they had been there longer, but somehow we either out-competed them for resources, killed them off, or simply bred with them until they folded in to us.  An interesting point that Chip makes is that they were unlikely to be able to communicate at the level we could because of the structure of their skull.  They likely communicated, but probably not in as sophisticated of a manner as we could.  With communication comes the sharing of ideas, the ability to cooperate to attain food, and culture.  With all of that, comes creativity.

Toward the end, Last Ape Standing goes over how cooperation and culture are 2 constructs that helped us become who we are.  He also discusses some very interesting ways in which some of our behaviors that are seemingly unrelated to our environment that may be a product of our environment.  He discusses a theory that people prefer younger looking mates because it would be an indication of the concept of neoteny mentioned earlier.  Younger looking people give the impression that they are aging more slowly, and aging more slowly, if it leads to better brain development, would be a desired trait.  He also discusses how both schizophrenia and autism may both be products of the brain misfiring during development, essentially neoteny gone wrong.  Again, timing is everything.

Honestly, I could have gone on and on about so many of the things that I pulled out of this book.  I can't think of another book that is under 300 pages that I pulled so much quality information from.  It's hard to hold my attention but this book managed to do it, so much so that I read it in 3 days.  This review could easily have been 3-4x as long as it was, but I have a felling Chip Walter wouldn't want me plagiarising his book on my blog.  I highly recommend anyone who wants to learn about what got us here to buy this book.  It is well written at a level most people with a high school education can understand.  Once I get done with a couple of other books that I just bought, I will buy Chip's earlier book Thumbs, toes, and tears: And other traits that make us human.

Thursday, January 2, 2014

Book review: The Paleo Manifesto by John Durant

If you've adopted the Paleo diet or read many of the books on how to eat this way, you have noticed that most of the books are pretty formulaic.  They start with a general overview of how we are maladapted to our environment, how this maladaptation is affecting our health, the specific aspects of our food environment that are maladaptive to us, and then present a 30 day plan to shift your ways of eating to the Paleo way.  When I picked up The Paleo Manifestion: Ancient Wisdom for Lifelong Health, I sorted of expected to get the same formula I have read time and time again.  In this instance, I was very happy to be wrong.

The way this book is written, you get a quick, albeit surprising introduction to where Mr. Durant is going from page 1.  John was one of the earlier adopters of the Paleo lifestyle.  While certainly not as early as Art De Vany, he adopted the Paleo lifestyle because his health deteriorated after leaving college and entering the 9 to 5 world.  He started a Paleo group in NYC and ever since has been blogging at  While a very small part of the book is a personal account, most of it is chock full of philosophical theories of how and why the Paleo lifestyle seems to work from a Harvard graduate who studied evolutionary psychology.

In the first part of the book, John does a great job of showing why the environment we evolved in is important for our health.  While some of this is rooted in our evolutionary past, most of it is done by relating the experiences of other animals as they are plucked from the environment they evolved in and placed in to the zoo.  Oddly enough, when you pull a primate from the environment it evolved in and is naturally suited for, it begins to experience the same health problems that many of us experience.  Type 2 Diabetes, heart disease, mood/anxiety disorders, odd eating behaviors, becoming overweight, and sexual dysfunction to name a few.

Caretakers in the zoo would often attempt to remedies these maladies in the same way we attempt to, with pharmaceutical drugs, but this doesn't work.  After trial and error, they found the best way to improve the lives of these primates is to make their enclosures in the zoo as similar to their natural environments as possible.  When they do this, the primates' health issues resolve and good health returns.  While what is in their diet is obviously a big factor, it was only one of the many variables that they changed.  For example, if you feed gorillas what essentially amounts to processed food containing grain, you're not only impacting what enters the body, you are also impacting how their body reacts to what you are putting in to it.  Gorillas have huge guts that burn a lot of calories processing fibers in plants that we can't.  When you feed them processed food which is basically pre-digested, they naturally burn fewer calories as they don't need to rely on their guts to break their food down.  This causes them to eat their food, throw it up, and then eat it again. Once their diet is shifted back to their native diet, this behavior stops.  They also tend to burn more energy rummaging around looking for plant materials to digest, far more than they would if you just tossed them some of the prefabbed pellets that they were accustomed to getting in the zoo that contained the nutrient profile that "science" identified as being optimal for gorillas.  Sounds kind of familiar, doesn't it?(*cough*Food Pyramid*cough*)

Another great aspect of this book is how John goes far beyond the singular variable of diet and gives a pretty good basis for deciding the importance of each environmental variable.  Environmental variables that we are constantly under, such as gravity, are very important as are cyclical variables such as light/dark cycles and the seasons.  When these variables are altered, they cause rapid changes in the way our genes are expressed, and thus, our health.  He mentions a few studies on the genetic effects of zero gravity on astronauts, which basically amount to increased aging.  Many of these genetic effects are mirrored in people who sit for long periods of the day and constantly expose themselves to artificial light 24/7.  One could easily make the argument that exercise exerts it's anti-aging effects this way, but I think this is framing the statement wrong.  Exercising doesn't reduce aging, not exercising increases aging as "exercise", otherwise known as physical activity, is the default condition we evolved to be good in.  In other words, we are meant to move, we are not meant to sit.

John covers quite a few environmental factors that are crucial to human health based on the fact that they have been a part of our environment for far longer than our written history indicates.  Being barefoot, getting daily physical activity in the form of walking, exerting ourselves regularly with exercise, forming social interactions, and going for periods of time without food(fasting) are just a few of the environmental factors he covers in the book.  I think most books on evolutionary health point to these things being important, I just feel that John does a better job at driving these points home with his writing style.

Probably the greatest thing I learned from this book is his take on religion and the focus of cleanliness in older religious texts.  Religion refers to cleanliness as being like godliness, and he makes a great case for why.  The most fascinating thing about this focus on hygiene is that they didn't have any way of knowing what was causing health problems back then.  Through trial and error, as well as the passage of time and many deaths, they were able to figure out their greatest predator's Achille's heel, practicing hygiene.  They were able to do this without hindsight or the help of a microscope to identify the actual cause of their number one cause of death, which is quite amazing.

Overall, I really don't know how to rate this book.  I suppose if I had to give it a star rating I would give it 5 out of 5 stars.  The reason it is so difficult to rate this book is because I don't look at the books that I read as x out of x stars, I look at them as either essential to developing my thought process or not.  One thing you have to realize is that there is very little direct science to back up much of what he proposes in the book because it simply hasn't been done.  This is the problem with looking at something like evolution, we have to fill in so many holes because we can't talk to people who lived thousands of years ago and there really is scarce evidence of their existence.  John does a fantastic job of laying out his ideas and this in turn has influenced many of my ideas, not only by improving them but also giving me a way I can relate them to other people.  As far as other books I have read, I put this up there with The Biology of Belief by Bruce Lipton as extremely influential to how I view human health.