Thursday, February 27, 2014

The human's guide to being human: The problem with gluten

Gluten is a component in our food that seems to make it's way in to the headlines every day.  What is gluten?  Should you eat gluten?  Is gluten really that bad?  How can someone eat gluten for years with no problem and then all of a sudden begin reacting to it?  These are all really good questions that deserve answers.  Unfortunately, people know little about what gluten is, even those that have pulled it from their diet.  In this blog we will take a look at gluten using the principles we have discussed in the "Human's Guide" series to help determine if gluten is really as bad for you as it's terrible reputation implies.

What is gluten and why is it problematic?

Gluten is a protein found in wheat that gives dough it's elastic qualities.  What most people don't know is that gluten is a catch-all term that refers to storage proteins found in wheat, barley, rye, and other grains that are called prolamins(1).  While not everyone reacts negatively to these storage proteins, they can often become problematic because humans cannot digest them.  Over time, this can cause people to suddenly begin reacting to gluten as well as other difficult to digest proteins such as the casein in milk or the globulins in legumes which are essentially their storage proteins.  This is why gluten sensitivity is likely a progressive issue and also why people with gluten tolerance issues tend to react to other problematic proteins.

This is not to say that some gluten containing foods can't be part of an otherwise healthy diet.  There are a couple of reasons that gluten seems to be causing issues in more people.  For one, the dosages we are exposed to day in and day out have increased dramatically over the last few decades.  Some of this is due to the fact that almost every meal we are exposed to contains gluten in some way.  Eating breakfast cereal or bagels in the morning, sandwiches and pretzels for lunch, and pasta for dinner are about as American as apple pie.

Another reason we are exposed to larger doses is because genetically modifying wheat causes it to make more proteins, including gluten.  A recent study found that people with irritable bowel syndrome who were given grain products made from an ancient form of wheat experienced an improvement in digestive symptoms while those who continued to eat modern grains did not(2).  Finally, with the rise of heavily processed foods and a sharp drop in fruit and vegetable consumption, the American diet is about as diverse as a Ku Klux Klan meeting.  These factors are all likely having a dramatic effect on our microbiome.

Protein digestion and gluten

Proteins are long strings of amino acids that are broken in to smaller peptides by our stomach acid and pepsin, a protein enzyme secreted by our stomach, as well as other protein enzymes in the small intestine.  In order for protein to be absorbed, it must be broken up in to it's constituent amino acids or peptide chains of no more than 4 amino acids.  Any protein that is not broken down in to small enough parts in the small intestine will make it to the large intestine where they are free to interact with the resident bacteria there.

Prolamins are long proteins that are high in the amino acid L-Proline.  What is interesting about this is that the human gut makes very little post-proline cleaving enzyme, an enzyme that helps break up larger proteins that contain L-Proline.  Since our guts do not make a lot of this enzyme, we have a difficult time breaking up proteins that contain high levels of L-Proline.  Since these long proteins are not broken down, we don't absorb them.  This is where they become problematic, if we don't absorb them they make their way through our digestive tract in tact.  When they make it to the large intestine, they can interact with bacteria there and wreak havoc on our microbiome.

In addition to reacting with the bacteria that make up our microbiome, gluten can interact with the intestinal wall which causes the release of a protein called zonulin.  In turn, zonulin causes areas between cells of the intestinal wall called tight junctions to dissolve, increasing the permeability of the intestine to the contents within it.  This allows the contents of your digestive tract to react with the immune system, 80% of which is located in the gut.  This causes you to begin reacting to larger proteins that are not meant to enter your bloodstream, as shown below.

The research of Dr. Alessio Fasano, the man who identified the protein zonulin as the cause of "leaky gut" and a major contributing factor to celiac disease and gluten sensitivity, notes that when gluten interacts with the intestinal wall of all people, it causes the release of zonulin(2).  In a healthy person, the tight junctions are resealed very quickly, in a person with celiac disease or gluten sensitivity, it takes much longer.  Dr. Fasano believes that gut dysbiosis, aka an altered gut microbiome, is a potential cause of this delayed sealing of the tight junctions.  There is indirect evidence that continually assaulting the microbiome with undigested proteins, particularly ones high in the amino acid L-Proline, may be able to trigger gut dysbiosis over time.  To illustrate this, let's take a look at just one of the thousands of species of bacteria that makes it's residence in your gut.

Candida Albicans: A day in the life of a commensal organism

Candida Albicans is a commensal organism, it lives in the human mouth and digestive tract and typically causes no problems to the human it benefits from.  However, Candida Albicans is able to convert back and forth between a yeast and a fungus depending on the environmental conditions it is in.  In it's yeast form, it is basically benign and may even provide some benefit to the host.  However, under certain environmental conditions, it changes from a yeast to a fungus where it can cause major problems and invade tissues.  In this way, what makes it's way through your digestive tract is critically important to the state of Candida Albicans because it affects the environmental conditions that it lives in, and thus affects the genes that are expressed.  But what causes Candida Albicans to morph from it's benign yeast form in to it's problematic fungal form?

Under alkaline conditions, such as those found toward the end of the large intestine, both the yeast and fungal forms of Candida Albicans contain a transport system for the amino acid L-Proline(3, 4).  L-Proline uptake induces the conversion of the yeast form of Candida Albicans in to the fungal form(5, 6).  Other amino acids do as well, including L-Glutamine, but L-Proline has the greatest effect.  In addition to free L-Proline, Candida Albicans is able to bind to the L-Proline found in larger proteins(7) that make their way to the colon undigested, which likely includes gluten.  Since Candida Albicans contains the enzyme L-Proline aminopeptidase, it is able to break L-Proline from these larger proteins(8) and induce fungal transformation.

Under more acidic conditions, such as those found at the beginning of the large intestine, Candida Albicans remains in it's yeast form as the change from yeast to fungus is blocked or reversed in acidic conditions(6).  However,  as a byproduct of amino acid fermentation, fungal Candida Albicans secretes ammonia which allows it to alkalinize the environment it is in(9).  This could allow fungal Candida Albicans to work it's way back up the digestive tract in to areas where it formerly couldn't convert in to it's fungal form provided enough amino acids and L-Proline are provided to promote alkalinization and fungal conversion.

A major factor of genetic expression that is determined by which form Candida Albicans is in is the gene for hyphal wall protein 1(HWP1).  HWP1 gene expression is very high in the fungal form of Candida Albicans but either not present or present in low amounts in the yeast form(10, 11).  HWP1 allows Candida Albicans to bind to the intestinal wall of it's host as well as tissues inside the body if it enters the bloodstream.  This could allow the fungal form of Candida Albicans to set up shop at the end of the large intestine while providing a continuous supply of undigested proteins high in the amino acid L-Proline from gluten could allow fungal Candida Albicans to alkalinize it's environment enough to work it's way back to formerly uninhabitable regions of the large intestine.  Ironically enough, fungal Candida Albicans has been implicated as a trigger for celiac disease as HWP1 has protein structures similar to the ones found in gluten that trigger an adaptive immune response(11).

Fungal Candida Albicans and gastrointestinal health

Fungal Candida Albicans can negatively impact digestive health in many ways.  In order to better understand how, we first have to take a look at what the beneficial bacteria are doing in your gut to promote gastrointestinal health.  There are thousands of different types of bacteria in your gut, but some of the best studied belong to the genus BifidobacteriumBifidobacteria ferment undigested carbohydrates such as soluble fiber and resistant starch in to short-chained fatty acids(SCFAs) such as butyric acid, acetic acid, and propionic acid.

These SCFAs have several important roles in intestinal health.  First, butyric acid is the preferred fuel for the cells of the digestive tract.  Butyric acid has been shown to improve peristaltic action by increasing contraction of the smooth muscle in the large intestine(12), but acetic acid is just as effective at a lower dose(13).  It is important to note that constipation, a common complaint of people with GI problems, is effectively a defect of intestinal peristalsis.

SCFAs, particularly butyric acid, have a direct effect on intestinal permeability.  Butyric acid increases the expression of tight junction proteins in intestinal cells whose tight junctions have been dissolved, re-sealing the intestinal wall and decreasing intestinal permeability(14).  SCFAs also indirectly reduce intestinal permeability through reducing inflammation in the digestive tract by promoting anti-inflammatory gene expression(15).  Increases in intestinal inflammation lead to an increase in systemic inflammation that increase intestinal permeability, allowing the contents of the intestine to react with the immune system.  When you get diarrhea, increased intestinal permeability fills the large intestine with water to flush it out.

Candida Albicans and acid/base reactions

The roles of the SCFAs are important to know because ammonia effectively eliminates them.  We all had the chance to experience, firsthand, the effects of combining acids and bases when we were in elementary school.  For those of you foggy on the details, the pseudo-volcano many of us made in science class out of baking soda and vinegar is a prime example of an acid/base reaction.  Baking soda, with a pH of 8.3, and vinegar, with a pH of 2.4, react and cause the rapid fizzing that resembles a volcanic eruption when placed in a partially enclosed cylinder with the top removed.  Could this same effect be one of the causes of the bloating many people with gluten sensitivity experience when exposed to the proteins in gluten?  Could it also be why beans, containing both hard to digest proteins as well as fiber, tend to bloat and cause gas?  It is interesting to note that vinegar is made from acetic acid, one of the SCFAs our beneficial bacteria make, and ammonia has a much higher pH of 11.0 than baking soda, which would cause a greater reaction than baking soda.

Bloating aside, there is experimental evidence that ammonia has a negative effect on intestinal health.  Cells of the rat colon cannot effectively metabolize SCFAs in the presence of ammonia when glucose levels are low, as would be the case toward the end of the large intestine(16).  In the absence of a healthy microbiome or the fermentable fibers that these types of bacteria use, ammonia levels can climb and ammonia can react with the cells of the intestinal wall.  By lowering the pH of the large intestine, SCFAs can help regulate the amount of ammonia being created as many of the amino acid fermenting bacteria that create ammonia, fungal Candida Albicans included, are inhibited by SCFAs and the acidic environment they create(17, 18, 19).


While this blog has focused on the interaction between gluten and Candida Albicans in the gut, the intent is not to target any specific commensal organism as the culprit.  Candida Albicans happens to be one of the few commensals we know a lot about because it has been studied at length.  There are thousands of different types of bacteria in your gut, and we have data on very few of them.  Any of the bacteria in your gut that can ferment amino acids are likely to have a negative effect on gut health if they overgrow simply because it is likely that they create ammonia.  Ammonia is made from 1 molecule of nitrogen and 3 molecules of hydrogen, and protein is the only macronutrient that contains nitrogen.

This is not to say that protein is the devil or that this process was always bad.  High levels of protein fermenting bacteria are associated with inflammation, which in turn is associated with insulin resistance.  While this is not necessarily a good thing now that food is plentiful, going in to the leaner months insulin resistant when food was scarce was likely a beneficial thing.  Consider it a way to activate the "thrifty" genotype.  Since both grains and legumes keep for much longer than fresh fruits and vegetables and are an acceptable nutrient containing food source, they may have been necessary for our survival in northern climates and the shifting food supply caused by weather before modern technology made most food available year round.  There is, however, a distinct difference between doing this for 4-5 months out of the year and doing it chronically over the course of decades.
Many people who undergo long term low carb diets notice an increase in their blood glucose despite not eating any carbohydrates.  It has been postulated that this is due to gluconeogenesis, the creation of glucose from protein, and something called physiological insulin resistance, a way that the body spares glucose for the brain.  This may not necessarily be something that is orchestrated at the level of the individual cell or even within the body at all.  The brain and gut are connected by the vagus nerve which is a conduit for communication between the bacteria in our gut and the brain.  Much of this phenomenon known as physiological insulin resistance may be orchestrated in the gut by the resident bacteria.

Reducing the amount of undigested protein that enters the large intestine is likely a good idea over the long term, but that doesn't mean that bread or pasta can't be part of a healthy diet.  To the contrary, in the face of a highly diverse diet, I believe that these foods can be enjoyed in moderation.  In addition, I believe that one can reverse gluten sensitivity under the right dietary conditions.  I am currently working on a program for this, and I don't believe that people with non-celiac gluten sensitivity need to spend years fixing the problem provided they are manipulating the proper variables.  We'll see how it goes.

Previous: Evidence against a Western Lifestyle 

Miss the whole "Human's Guide" series and want to learn about how your body works?  Click here.

Monday, February 24, 2014

Health Research Recap (Week of February, 17, 2014)

Researchers found that children who were exposed to even mild to moderate family problems between birth and the age of 11 experienced impaired brain development when compared to children who didn't experience these problems.  The children who experienced this stress had a smaller cerebellum, a part of the brain responsible for motor development, skill learning and stress regulation.  The children were also more likely to experience psychiatric illnesses later in life.  An interesting aspect of this study was that children who experienced the problems later, around the age of 14, actually experienced an increase in cerebellum size, indicating that when the child is exposed to stress is an important factor as well.

Researchers and Norway have identified a link between hip fractures and magnesium intake.  They started by looking at the distribution of hip fractures in Norway as hip fractures are common there.  Once they established the areas where hip fractures were happening, they began looking at the magnesium and calcium content of the local water supply.  They found that people in areas where there was more magnesium in the water were less likely to experience a hip fracture than people who lived in an area that had less magnesium in the water.  They found no link between the calcium content of the water and hip fracture risk

Levels of the hormone Irisin, a hormone released after exercise, can be used to predict biological age in humans.  Irisin helps the body set metabolic rate by signaling fat cells to burn energy rather than store it.  Irisin isn't only important for metabolism, it's important for brain function as well.  Aside from it's job in helping regulate metabolism, Irisin also increases secretion of brain-derived neurotrophic factor, an important protein that is neuroprotective to the brain and thought to help prevent neurological diseases.  BDNF works by helping current neurons in the brain survive and by building new neurons, a process called neurogenesis.  While chronological age(Age in years) is what most of us use to define age, biological age can be defined by the biological state of the body.  Someone who is 50 years old but has better brain function, muscular function, and appears younger looking than someone who is 40 has a lower biological age.  People with higher levels of Irisin after exercise were younger in biological age than people with lower levels.

Taking high doses of the antioxidants Vitamin E and selenium may not be a good idea for men who don;t need them.  A recent study found that taking Vitamin E or selenium a standalone supplements increase a man's risk for high grade prostate cancer by 111% and 91%, respectively.  In an otherwise healthy person who is not deficient in these nutrient, there is no proven benefit to taking them.  The study did not look at using them as part of a multivitamin.  Unless you are using vitamin E or selenium to correct a deficiency with the help of a medical practitioner, I'd stay away.

We all know that teaching your children about the importance of a good diet can help them remain slim throughout life.  A new study found that being an involved parent, in general, can also help your children become slim adults.  The involvement doesn't need to necessarily be centered around food.  Just playing with your child, asking them how their day went, or just spending time with them are all potential ways to improve their chances of not becoming obese as they grow old. 

Involving children in developing programs to reduce obesity can have a powerful effect.  "Sodabriety", a program developed by teens in Appalachia to reduce sweetened beverage consumption has been very successful at reducing soda consumption and increasing water consumption.  Involving the people you are trying to change in designing the change can promote a sense of identity and togetherness as well as reducing the potential for negative peer pressure.

It appears that there may be something behind the notion that our tinkering with wheat has caused it to become more of a problem than it used to be.  People with IBS reported an improvement in digestive symptoms when they ate wheat products made from an ancient species of wheat.  When they ate modern wheat, there was no improvement in symptoms reported.  Furthermore, blood tests revealed a decrease in inflammatory markers when people were eating wheat products made from the ancient strain but not when they were consuming the modern strain.  Get ready for a flood of "Ancient" bread products in 3...2...1...

Finally, low and middle income families who live in areas with high fruit and vegetable prices are more likely to have children who are obese than people who live in areas where these foods are lower in price.  Families living in areas with high soda prices were less likely to have obese children, but this effect was not seen in areas with higher priced fast food.  They pointed out this may simply be a product of supply and demand, and areas with people who eat more fast food are more able to raise their prices than areas where people eat less fast food.

Thursday, February 20, 2014

The human's guide to being human: Evidence against the Western lifestyle

Over the course of the past 5 blogs, we have gone over how organisms on the planet interact with the environment and how this interaction leads to adaptability of the individual as well as evolution of the species through gene/environment interactions.  It is important to note that our ability to adapt to different environments has allowed humans to populate every continent on the planet except for Antarctica, something no other animal has done.  However, our ability to adapt is constrained by the genome that was developed over millions of years of evolution.  Furthermore, as the environment changes, traits that were once beneficial to our ancestors can become detrimental to us.  Since there are still pockets of people living in the same basic conditions our species evolved in, we can look at the difference between attributes of their lifestyle and compare it to ours to see if some of the diseases that we experience are products of a bad gene/environment interaction.  With advances in medical technology, we can also look at how different lifestyle factors change gene expression in a way that can lead to poor health.

Comparing Western lifestyles to modern day hunter gatherers

When we take a look at the health of modern day hunter gatherers, one thing is abundantly clear; they die in different ways.  While people living a western lifestyle are likely to die of Cancer or Heart Disease, modern hunter gatherers are likely to die of infection or from a violent cause.  Modern medicine has afforded people in the west the ability to avoid dying of infection and societal norms dramatically reduce the risk that you will die of a violent cause.  However, the notion that western people die of chronic diseases such as Cancer, Type 2 Diabetes or Heart Disease because they live for much longer aren't entirely true.  In fact, in modern day hunter gatherer societies, these diseases are quite rare even in those who live to older ages.  There is some evidence that the chronic diseases of aging are a product of our ancient genes interacting with our modern environment.

In 1984, Kerin O'Dea published a landmark paper that showed that when Australian Aboriginals who had developed Type 2 Diabetes while living a western lifestyle were reverted back to their traditional lifestyle, their insulin resistance improved dramatically in 7 weeks(1).  This is a big deal because Type 2 Diabetes increases your risk of both cancer and heart disease, among other things.  Many other factors associated with cardiovascular disease such as high blood pressure, high triglycerides, and high BMI also improved.  When you look at the environment these factors create within the human body and how the body responds to these factors, you can get a clear idea of how a western lifestyle can contribute to chronic disease.

Three conditions associated with chronic disease

When you look at Cancer, Type 2 Diabetes, and Heart Disease, there are 3 conditions within the body that are prevalent in all 3.  High levels of inflammation, blood glucose, and oxidative stress coupled with mitochondrial dysfunction are prevalent environmental conditions within the body in all 3 diseases.  In addition, people with Diabetes are far more likely to develop Cancer or Heart Disease.  Since Diabetes is a disease whose primary symptom is high blood glucose levels, and high blood glucose levels increase levels of inflammation and oxidative stress, this makes sense.  But what are these three conditions and how does the western lifestyle promote them?

Inflammation is part of the vascular system's response to harmful stimuli such as foreign invaders and damaged cells.  When you jam your toe against the wall, or a pathogen enters your bloodstream, the body responds by increasing inflammation, a vital part of the repair process.  In the example just mentioned, inflammation is acute and subsides in a relatively short period of time.  The inflammation associated with Cancer, Type 2 Diabetes, and Heart Disease is not acute, it's chronic and contributes to many negative processes within the body including arthritis, plaque accumulation on blood vessel walls, allergies, and is a central regulator of the environment around cancerous cells.  In other words, chronic inflammation is very bad.

Oxidative stress occurs when free radicals react with healthy tissues in your body.  Free radicals are unstable molecules that have an unpaired electron in their outer shell.  To remedy the situation, they go around to healthy, stable molecules and steal electrons from them, causing them to become free radicals.  Oxidative stress is when free radicals build up and overwhelm your body's ability to remove them.  As a result, parts of your cells become damaged and malfunction.  Organelles found within your cells called mitochondria are especially at risk for damage because many free radicals are produced as a natural byproduct of metabolism within the mitochondria.  This does not mean free radicals are bad, they are necessary for proper cell function.  But when too many of them build up and react with mitochondrial DNA, this causes bad mitochondria to be produced which causes more free radicals to be produced.  This process is called mitochondrial dysfunction and is discussed in more depth here.  Needless to say, having high levels of oxidative stress is a terrible state for your cells to be in.

Consistently high blood glucose is a hallmark of Type 2 Diabetes and is likely how many of the symptoms and co-morbidities associated with Type 2 Diabetes occur.  The process is quite simple.  High blood glucose levels cause your pancreas to secrete the hormone insulin which causes cells to take in glucose from the blood.  Eventually, your cells cannot take anymore so they begin to ignore insulin.  This process is termed insulin resistance.  Since blood glucose levels remain high, more insulin is secreted which leads to a state of high insulin levels, which is inflammatory.  In addition, high levels of blood glucose induce oxidative stress(2), particularly in the eye, kidney and blood vessels.  Finally, another hormone called leptin, which is key in the regulation of appetite, begins to climb as the brain becomes resistant to it.  Unfortunately, leptin is a highly inflammatory hormone.

Through this process, you are creating an environment that is extremely bad for your cells.  Perhaps the chronic diseases that are typical of the western lifestyle are simply how human cells adapt to an environment with excessive inflammation, high levels of oxidative stress, and high blood glucose levels.  Through the study in Australian Aboriginals, we can see that the reversal of Type 2 Diabetes in Aboriginals who went from a western lifestyle to the more traditional hunter gatherer lifestyle points to Type 2 Diabetes as being a disease caused by poor gene/environment interaction.  In hunter gatherers, the absence of the chronic diseases that are prevalent in western society provides further support that the chronic diseases of aging are not diseases caused by aging, they are merely diseases associated with aging.  However, we need to pinpoint the aspects of the hunter gatherer lifestyle that are different from those of people in the west and that are important to health.  While there are many aspects of these lifestyles that are different, three stick out like a sore thumb.  These 3 factors are sedentary time, altered circadian rhythm, and diet.

Lifestyle and genetic expression

When you look at the life of hunter gatherers compared to western people, it is readily apparent that hunter gatherers sit for far less time.  On top of getting food every day, hunter gatherers also don't have Barcaloungers to sit on.  While they may sit from time to time, they don't tend to sit for 8 or more hours a day like we do.  High levels of sedentary time are associated with high insulin levels, high blood glucose levels, and poor fatty acid metabolism.  Furthermore, many genes related to antioxidant and anti-inflammatory pathways as well as glucose metabolism are downregulated during periods of sedentary time but are upregulated when these periods of sedentary time are broken up with periods of activity(I blogged about this here).  If you are looking for an easy way to reduce inflammation, oxidative stress, and blood glucose levels, reducing the amount of time you spend sitting each day is as good as any.

Sleep is another lifestyle factor that is quite different between hunter gatherers and people in western societies.  Sleep as well as light and dark cycles set the stage for proper circadian rhythm.  When compared to hunter gatherer cultures, most of us in western cultures are severely sleep deprived.  This sets the stage for poor health by influencing the expression of hundreds of genes associated with health.  A study that compared 1 week of sleep deprivation(5.7 hrs per night) to 1 week of adequate sleep(8.5 hrs per night) found that sleep deprivation causes a downregulation of genes associated with anti-inflammatory and antioxidant pathways as well glucose metabolism when compared to adequate sleep.  In addition, many genes that are associated with circadian rhythm were also disrupted(3).  In total, the expression of 711 genes was altered when people were sleep deprived.  Getting adequate sleep is another easy way to improve the environment your cells are in, potentially reducing your risk for the chronic diseases of aging.

Of the 3 lifestyle factors that are obviously different between hunter gatherer and western cultures, diet is the most tricky because it is the most complex.  Is it the carbs?  Is it the fat?  Is it the calories?  While most of us seem to be preoccupied with these 3 questions, a case cannot be made for any of them.  Hunter gatherers live on many different ratios of carbs to fats and calorie intakes will fluctuate based on the availability of food.  The only thing we know for sure that is different between what hunter gatherers and western people eat is that hunter gatherers don't eat heavily processed foods.  Sure, they ferment, cook, chop, and soak many of their foods, but they aren't eating bread, pasta, cereal, or other foods that come in a box because they simply lack the technology to do so.

Remember, your genes aren't the only genes

We also know that the microbiome of hunter gatherers is vastly different from ours, but there is likely a large variability between the microbiome of different hunter gatherer cultures based on what they eat.  One thing we do know for sure is that hunter gatherers likely have a much more diverse microbiome because their diets are much more diverse than ours.  If you look  at the diets of most western cultures, they are mostly wheat, meat, dairy, and a few different types of fruit and vegetables.  I don't know for sure, but I believe one of the primary issues with our diet is that it's not diverse at all and contains many processed foods that can have a negative affect on our microbiome.  I believe this manifests itself in the form of Celiac disease and other forms of IBD which are all but nonexistent in modern hunter gatherer cultures but seem to be on the rise in the west.  (I have no direct evidence of this, but I have sound theory that I will expand upon in next Thursday's blog)  Remember, a change in the microbiome is effectively a change in the genome since there is more genetic material there performing biological functions for us than in our own cells.  The simple fix is to avoid or limit processed foods and eat a diverse diet.


Overall, using the evolutionary template as well as the way in which our bodies work provides compelling evidence that many of our health problems are related to a mismatch between our genes and the environment they are currently in.  When you look at other cultures who still live in a way very similar to the way our species evolved, they simply do not suffer from the chronic diseases of aging that are prevalent in western civilizations.  I am not suggesting that we abandon all we have gained over the past few thousand years.  On the contrary, I believe a combination of the advances we have seen in medicine and the knowledge that can be gained through an evolutionary perspective on lifestyle can lead us to even greater longevity than we see today.  This doesn't mean that everyone who applies these principles will live to 100, but it does means that you can maximize both your time and quality of life by living in a way that is congruous with how our species developed.

That about does it for the background information on how humans function.  From time to time I will tackle specific aspects about our lifestyle and health and how they fit in to this framework.  Next Thursday I will tackle gluten and the primary issue with it's consumption as well how it is able to create a bad environment for those who overconsume it.  Using the Human's guide framework, we'll take a look at why you can consume it for so long before acquiring symptoms of sensitivity.

Previous: Evolution and adaptation                                                                   Next: The problem with gluten

Monday, February 17, 2014

Health Research Recap (Week of February 10, 2014)

There has been a lot of information that supports the notion that a person's mood has an influence on their food selection.  A series of studies has shed some light on how mood may effect how we see our food.  The first study found that people in a positive mood were more likely to rate nutritious food as favorable to more indulgent foods.  The second study found that people in a bad mood were more likely to rate indulgent food more favorably nutritious food.  The most interesting finding from this group of studies is that a person's mood affected something called time construal.  A good mood allows people to make decisions that are more beneficial in the long term, such as choosing healthier food that will lead to better health down the road.  People in a bad mood are more likely to make decisions that lead to immediate satisfaction, such as the relief many people experience from the taste of indulgent foods.  The researchers recommend a double whammy approach to solving the problem of bad food choices in the face of a bad mood.  By focusing on the future effects of food while at the same time providing mood relief in a form other than food, such as talking with a friend or exercising, may help you make better food choices when in a bad mood.

An amino acid found in spinach and eggs has been shown to improve reflexes/reaction time.  The amino acid L-Tyrosine was shown to enhance reaction time when subjects were told to press a button as quickly as possible once a green arrow flashed on a computer screen.  The subjects performed the task faster when they were told to drink orange juice fortified with L-Tyrosine versus when they drank unfortified orange juice.  This effect jibes with L-Tyrosine's role as a precursor to neurotransmitters, particularly dopamine and norepinepherine.

People often associate the development of Type 2 diabetes with obesity and believe it to be due to recent weight gain.  A recent analysis of data from the Whitehall II study indicate this may not to be true.  The researchers looked at data compiled over the course of 18 years and found that obese people who developed Type 2 diabetes fell in to 3 groups.  The largest group (94%) was comprised of people who were stably overweight throughout data collection, with a worsening of insulin function 5 years prior to diagnosis.  The next group was comprised of people who gradually gained weight over the time of data collection (2.3% of diabetics), they noticed a sharp worsening of insulin function a few years prior to diagnosis.  The final group was comprised of people who were severely obese throughout the 18 years(3.7%).  These people noticed early increases in insulin secretion followed by decrements in the function of the cells responsible for insulin secretion. 

Using accelerometry-based technology, things like the Nike Fuel Band and the Fitbit, researchers have been able to identify activity patterns in obese and healthy Americans.  As a whole, Americans spend 15 hours per day either siting or sleeping.  Obese people spend less than a minute per day engaged in intense physical activity and have lower amounts of general physical activity compared to everyone else.  They also slept less which means they spend more time sitting than their counterparts.  The negative effects of these habits on genetic expression pretty much put to rest the notion of the healthy obese.

If you're from a northern latitude you are more likely to be obese than someone in a southern latitude.  The same holds true for animals, those in more northern latitudes tend to be larger than their counterparts in southern ones.  It turns out that gut bacteria may have something to do with this.  In a study looking at the geographical variation of gut bacteria between people, scientists found that people in northern latitudes had a microbiome that more closely resembled that of an obese person than people living in southern latitudes.  Obese people tend to have more firmicutes and fewer bacteroidetes than lean people, and as the scientists looked at how the ratio of these two types of bacteria varied by geographic location.  They found that the amount of firmicutes increased as you moved north while the amount of bacteroidetes decreased.  They believe this is a result of people in the more northern latitudes having a microbiome that more effectively extracts energy from food.  This makes sense, for most of our evolution the winter months are a time when food was typically not as plentiful as it would have been during the spring and summer.  Being able to extract more energy would have been an advantageous thing, at least until food became plentiful and not so seasonal.

In other gut bug news, scientists have identified an enzyme in a prominent species of bacteria found in the human gut that helps them digest phytates and released some of the nutrients phytates bind to.  In addition, this enzyme is also a means of communicating between this bacterium and our cells.  The enzyme is found in something called an outer membrane vesicle(OMV) which allows phytates in where the bacteria can liberate nutrients.  The enzyme also appears to be a method for altering calcium signaling in cells of the colon, which can affect any number of processes in these cells.

Regular daily physical activity such as walking may cut women's stroke risk by 20% and help ameliorate some of the increase of stroke risk in women undergoing hormone replacement therapy.  If it seems like I'm beating a dead horse with all of these walking recommendations, it's because most people fail to realize that 4-5 hours of exercise per week is not the same thing as getting sufficient physical activity every day.  Sufficient physical activity would be getting in more than 10,000 steps per day or walking approximately 5 miles per day.  For most people, their general daily activities will get them at least 4,000 steps, after that it's basically just an extra hour of walking every day.

Finally, if you wondered why nutrition research changes so much and how it's so difficult to follow, Gary Taubes gives a pretty good rundown on why the nutrition research that many of us read about is so flawed.  Check it out here.

Thursday, February 13, 2014

The Human's guide to being human: Evolution and adaptation

If you look at the 3 aspects of your genome, you can see that each allows adaptability but over differing time periods and scales.  Your coding genes don't change during your lifetime so they don't help to make you, as an individual, adapt to the environment.  What they do is allow the species, as a whole, to change as the environment changes and provide a framework for adaptation to occur.  The epigenome gives you some ability to adapt to the environment by changing the way genes are expressed, but you are still restricted to what you can do by your coding genes.  Finally, the microbiome allows you to adapt to the environment quickly based on the microbes you come in to contact with and the food that you eat.

If you truly think about it, adaptation is going on everywhere here.  The environment in your gut causes your microbiome to adapt which changes the internal environment, your internal environment makes your cells adapt via the epigenome, and the species as a whole adapts via evolution as certain coding genes make some people more successful at interacting with the environment than others and those people pass those genes on to future generations.  But what is the difference between adaptation and evolution?

The difference between evolving and adapting

There is a distinct difference between evolving and adapting.  Adapting occurs in individuals and is brought about by the environment affecting change on that individual.  A good example of this can be seen in weightlifting.  When you begin lifting weights and don't wear gloves, you develop calluses on your hands.  This makes the skin stronger and less likely to rip the next time you lift weights.  You are basically adapting to the stress being placed on your hands by making the skin a little stronger for next time.  The adaptation doesn't stop at the hands, over time your nervous system becomes more efficient, you lay down more muscle fibers to make you stronger, and your bones become more dense as a load is placed through them and/or the muscles you are using cause deformations of the bone which signals them to get thicker.  These are all adaptations and they make you better at lifting weights.

Evolution, on the other hand, doesn't happen to an individual, it happens to a population.  Over the course of your life you adapt to the environment, but you don't evolve.  The species as a whole, or a sub-population of the species, evolves over long periods of time as it becomes better suited to the environment, but individuals within the population are not evolving, they are adapting.  I only bring this up because many ill-informed people discredit evolution by saying that it cannot be true because we don't see humans actively evolving in to monkeys.  The human species evolves, individual humans adapt.

Let's take a look at an example of each.  Let's say we have a population of mice where half are white and half are green.  If we take this population of mice and place it in an environment where the ground is covered in green flora, the green mice would have an advantage over the white mice because predators would be less likely to see the green mice.  As a result, the number of white mice would begin to dwindle and the green mice would begin to outbreed the white mice, leading to most of these mice being green.  Let's say some of the white mice were exceptionally smart and were able to realize that looking for food at night allowed them to procure food AND reproduce without being killed by some of their predators.

This would allow a few white mice to still be kicking around when an ice age came about and the white mice became better suited to being able to hide in this new environment where the ground was mostly white.  As a result, you would see the white mice begin to outbreed the green mice and eventually become more numerous.  The change from equal parts white and green mice to mostly green mice to mostly white mice is evolution of that species.  The individual white mice who were able to adapt to the environment by hunting at night allowing that segment of the population to stick around long enough for the white color trait to be beneficial, that is adaptation. 

How evolution affects our health

Evolution is important to understand because the environment our ancestors lived in caused our species to evolve.  This is not the same thing as saying the environment molded us to become well adapted to it, that never happened.  It's also not the same thing as saying we were perfectly adapted to any particular environment from our past, as far as evolution goes there is no such thing as perfect and environments change quickly which can cause formerly beneficial traits to quickly become a liability, as seen above.  I don't think anyone would argue that our cravings to devour high sugar/high fat/salty foods is no longer beneficial to us in an environment where food is plentiful and food companies exploit these cravings to get us to buy and overconsume their products.

This also doesn't mean that we cannot be better suited to a different environment, it just means that if we are not doing well in a particular environment we can look at the environment our ancestors lived in and compare that to the environment we are currently in to identify aspects of the new environment that we may not be well suited for.  Since we are individuals, adaptation is our primary concern because we do not evolve, but remember that our ability to adapt is constrained by our genome, which was developed through evolution.  There is no doubt that the environment we are in is drastically different from the one most of our ancestors adapted to and the human genome as a whole evolved in, and science is beginning to allow us to peel back the onion and take a look at this from a genetic perspective.


The environment our species evolved in for the vast majority of time on this planet was devoid of processed foods, high in physical activity, and low in sedentary behavior.  Being a couch potato is a relatively new option for individuals of our species since our ancestors actually had to procure their food through more physical means than calling Domino's.  Furthermore, our bodies are not well suited to experiencing stress the way we do today.  For most of our time on the planet, stress has been intermittent and resolved very quickly.  If you encounter a bear in the woods and it wants to make you lunch, you either get away or become lunch, you may become more conscious of bears in the area but you don't lament about it for a month.  Stress was more acute back then, it's more chronic now.

Chronic stress is a more recent physiological problem that's been brought about through society.  All of these things have an impact on our internal physiology and, thus, the environment our cells are in.  It's not too big of a reach to think that these lifestyle factors can impact our health by causing our cells to adapt in a way that isn't healthy for us.  New studies on the way lifestyle decisions impact genetic expression are beginning to open up our eyes to the way our lifestyle choices impact our health.  In my next blog we will look at how our new environment is clashing with our old physiology and what the research shows about how this affects our health.

Previous: Your microbiome                                                         Next: Evidence against a western lifestyle

Monday, February 10, 2014

Health Research Recap (Week of Feb. 3, 2014)

Findings of a new study suggest that symptoms of autism may occur earlier than expected.  The study found that children who developed autism averted their attention from the face of those who were speaking to them, and failed to pay attention to key aspects of the face related to speech processing such as the eyes or mouth as early as 6 months of age.  Being able to identify the disorder early may give parents a chance to begin therapeutic intervention earlier, potentially altering the course of their child's development in a positive way.

If you feel like you can't download your stress to you child, you may want to think again.  A study looking at the effects of a mother's stress on her child found that children not only pick up on their mother's stress, their heart responds as if they themselves have been stressed even when they don't experience the stress themselves.  Women who had a 12-14 month old infant were exposed to one of 3 situations where they gave a speech and were given either positive feedback, negative feedback, or no feedback at all.  When the mother was reunited with her child, her child's heart responded in a way that was indicative of the mother's experience.  Not only did the children whose mothers were given bad feedback have higher heart rates than those who received positive feedback, the children of the women who responded most strongly to the stress had higher heart rates than those that responded less to the stress.  time to take up meditation.

A study on providing better access to healthy food in low income areas found that while providing access to healthy food improved people's perception of accessibility, it did not translate in to healthy food behaviors.  The study, conducted in a low-income area of Philadelphia, shows that providing healthy food choices isn't enough to get people to make healthy food choices and did nothing to reduce obesity or increase fruit/vegetable consumption.  Educating the public on why they should make healthy food choices is likely necessary to provide the incentive to do so since unhealthy food tends to be cheaper and more convenient to make. 

A study on the effect of lowering blood pressure on reducing cognitive decline in patients with Type 2 Diabetes found that intensive blood pressure therapy had no effect on reducing cognitive decline.  In addition to not reducing cognitive decline, the patients who underwent intense blood pressure lowering therapy had lower total brain volumes than patients who underwent standard blood pressure lowering therapy.  The takehome from this...Ameliorating symptoms of a condition doesn't typically resolve the problem.  Big surprise there.

A study on sugar found that high sugar consumption dramatically increases your risk of dying from heart disease whether you are obese or not.  In people who consumed 15% of their calories from sugar, the amount found in 2 cans of soda per day and the average US consumption, the risk of dying from heart disease increased by 20% compared to those who consumed less than 10% of their calories from sugar.  In those who consumed 25% of their calories from sugar, an amount 10% of people manage to hit, the risk of dying from heart disease increases by 300%.

Researchers looking at the effects of diets high in Omega 3 oils found that monkeys who were fed a high Omega 3 diet had better neural connections in the brain when compared to monkeys who ate a diet low in Omega 3 fatty acids.  The enhanced brain connectivity was similar to what you would see in a human.  This supports the notion that omega 3 fatty acid consumption likely played a pivotal role in the evolution of the human brain.  It is believed that our primate ancestors climbed out of the trees and scavenged the organ meats from fallen prey.  Organ meats are particularly high in the Omega 3 fatty acids, particularly DHA.  DHA is crucial to brain development as it is a major structural component of the human brain.

Looks like those low fat diets may have lowered cholesterol, but they don't lower heart disease risk.  A review on the effects of dietary focus found that focusing on a diet of whole foods such as nuts, vegetables, fruits, and fish was more effective than focusing on a diet low in fat when it comes to reducing the risk of heart attack.  The Mediterranean diet was particularly effective, but any diet that reduces processed food while focusing on whole nutritious foods would do the trick.  Hopefully this reduces the ridiculous focus on macronutrients(Carbs and fat particularly) that seems to be prevalent today.

Another study on the Mediterranean diet found that it was effective at reducing risk for the metabolic syndrome, a combination of risk factors such as high blood sugar, high blood pressure, high triglycerides, and low HDL cholesterol that are associated with heart disease.  The study found improvements in all risk factors in firefighters who followed the diet, and the improvements were greatest in those who followed the diet more consistently.  Those who followed the diet best saw a 35% decrease in risk for the metabolic syndrome.  This study is pretty neat because the firefighters weren't told to eat a Mediterranean diet, researchers came up with a way of assessing how closely the firefighters' diet resembled the Mediterranean diet and compared that to health outcomes.  Of course, this means this study only show a relationship, it could simply be that people who eat a diet closer to the Mediterranean diet are more health conscious as most nutritional recommendations follow principles of that diet.

Add better vision through old age to the list of benefits you can get from exercise.  A study in animals found that exercise slowed retinal degeneration in mice.  Mice were exercised on a treadmill for 2 weeks and measured the damage their eyes experienced from bright light.  The mice who exercised had less damage from the light and higher levels of brain-derived neurotrophic factor(BDNF) than mice who didn't exercise.  When the effects of BDNF were blocked in the exercising mice, they were not protected from the damage from the light, indicating that BDNF plays a pivotal role in the process.  BDNF has been researched heavily because it also appears to be pivotal in the enhanced brain function seen in people who exercise as it enhances neural connections in the brain.

Finally, studies have shown that pesticide exposure are associated with an increased risk Parkinson's disease.  A new study found that this risk is epigenetic, and can increase a person's risk of Parkinson's by up to 600% depending on their genetic make up.  It is important to note that the study didn't look at exposure to the particular pesticide from ingesting food, it came from using the pesticide at home or outside.  This shines a light on why we need to be careful before we start introducing these types of things to the population as a whole.  While using pesticides may present no risk to a large percentage of the population, it may present a huge risk to a small percentage of the population who carry a specific gene variant.  So while the numbers on a study may show that there is little effect of exposure to most of the population, that's likely no solace to the few who get a disease like Parkinson's from it.

Thursday, February 6, 2014

The Human's guide to being Human: Your microbiome

While all biological functions occur through gene/environment interactions, most life on the planet is not possible without some form of assistance from a different form of life.  Most plants could not reproduce without pollination by insects and therefore they would not exist today without a little help from their friends.  This type of symbiosis is not reserved only for members of the plant kingdom, members of the animal kingdom, including humans, require some assistance too.

I'd like to begin this blog with a couple of questions.  What do termites eat?  If you're like most people, you know the answer to this question is wood.  However, if I were to tell you that termites are incapable of digesting wood, you may become a little confused.  The truth is, termites consume wood and as it makes it's way through their digestive tract, microbes found within their digestive tract break down the wood in to something termites can use to perform their every day functions(1).  Despite lacking the enzymes capable of breaking down wood in to something that is useful to them, termites are able to consume wood and get something out, but only with the help of bacteria capable of breaking it down first.

For my next question, I'd like to ask you if the diet of Gorillas is high in carbohydrate or high in fat?  Gorillas typically consume large amounts of fiber, a carbohydrate, as well as some fruit, also high in carbohydrate.  Since gorillas don't eat canola oil and aren't seen tearing apart other animals for food, it seems logical that a gorilla diet is a high carbohydrate diet then, right?  Not so fast.  Similar to the microbes found in the gut of the termite, microbes in the gut of gorillas break down fiber that they can't digest in to short chained fatty acids that the gorillas can absorb and use for energy.  All tolled, including fiber as a carbohydrate, Western Lowland Gorillas consume 84% of their diet in the form of carbohydrate.  However, once that is acted upon by the microbes in their gut, almost 60% of what enters their circulation is fat(2).  Without microbial fermentation of this non-digestible fiber in their gut, Gorillas would not have access to more than 57% of the calories they consume.  In other words, they could not exist without these microbes.

In humans, upwards of 1000 different species of bacteria live in the gut.  In addition to the gut, these bacteria can be found anywhere the body is exposed to air including the skin, mouth, eyes, and nose.  It may not seem intuitive that the digestive tract is exposed to air, but in actuality the digestive tract is a tube open on both ends, the mouth and anus.  In other words, it is not a part of your internal environment, it is actually an interface between the external environment and your internal environment, much like the skin.  Bacteria that reside in the gut perform a host of functions including digesting fibers we can't use in to short chained fatty acids that we can, training our immune system, regulating the integrity of the intestinal wall, manufacturing vitamins, and helping transport minerals just to name a few.

The collection of bacteria found within your gut is often referred to as your microbiome.  It is estimated that there are 100x more genes in your microbiome than there are genes within your cells.  In other words, from a biological function perspective you are more bacteria than human.  While all of the above mentioned functions are beneficial to us, the gut is not a sanctuary for good bacteria, bad bacteria can also reside there.  Depending on what you eat and the microbes you are exposed to, any number of good or bad bacteria can take up residence in the gut and perform their biological functions.

In the case of good bacteria, there is typically some benefit to the host in them being there.  Bad, also called pathogenic, bacteria tend to cause problems by either activating the immune system or secreting toxins directly in to the host.  In a way, your gut is like the petri dish mentioned in my last article on how cells work and the bacteria are merely vehicles for the genes that they contain since all biological functions are a product of gene/environment interaction.  By filling the petri dish with "food" that benefits a certain type of bacteria, you are effectively altering the genome found within that petri dish, in this instance your gut.  In this way, your microbiome is actually a more adaptable part of your total genome.  While your coding genes are fixed from birth, and your epigenome can change but over longer periods of time, your microbiome can change relatively quickly based on the type of food that's available.  In fact, a recent study showed that switching from a mixed diet to an all meat diet can cause the microbiome to change significantly in as little as 2 days(3).  Stress and sleep are also believed to impact the microbiome as would anything that directly affects either one.

Our microbiome is developed relatively early in life and changes as we age.  When we are born, we are exposed to the vaginal flora as we exit our mother's birth canal.  Those who are born via C-section do not get this exposure because they are removed via an incision in the stomach, which could lead to health issues much later in life.  Breast milk is another way we get exposed to beneficial bacteria early in life, so those who are not breast fed are at a further disadvantage in developing a healthy microbiome.  As we are able to crawl and interact with our environment as babies and toddlers, we also expose ourselves to more bacteria that will become part of our microbiome.

The hygiene hypothesis postulates that one of the reasons we have seen an increase in allergies and autoimmunity is because our focus on preventing children from ever coming in to contact with microbes from the environment prevents the immune system from developing properly.  There is evidence that there is something to the hygiene hypothesis as children raised on farms or with pets are less likely to experience allergies or autoimmunity.  Furthermore, the microbiome has been implicated in a range of health problems from autism to depression to obesity so there is the possibility that the microbiome is responsible for multiple areas of development, not just the immune system.

Even once you've entered adulthood, the microbiome will continue to change throughout life.  Combined with changes to the epigenome, the microbiome can dramatically change your health.  Studies in identical twins show that the same coding genes put through different environments can yield completely different outcomes.  There are identical twins where one is obese and one is lean.  There are identical twins where one dies of cancer and the other never gets the disease.  These changes can only come about through a change in the environment in which the genes are exposed to since the genes are identical.  We can adapt to a wide variety of environments, and this flexibility is afforded to us by the epigenome as well as the microbiome.

An interesting aspect of the microbiome that bears mentioning is that the appendix may be a reservoir for all of the types of bacteria that make up our microbiome.  When an infection of some sort occurs in the digestive tract, the colon pulls water out of circulation which causes diarrhea, a flushing of the digestive tract that removes both good and bacteria.  Then, based on the types of foods you eat, you will begin repopulating your colon with bacteria that were hiding in your appendix that make their way out and in to the colon where non-digested food arrives.  This is just a hypothesis, but it certainly makes me relieved that I still have my appendix and wasn't one of the people who had appendicitis and convinced it was useless, or more "junk" so to speak.

If we look at the traits of the 3 parts of the genome, we can see that each affects change differently.  The microbiome allows you as an individual to adapt to the environment quickly based primarily on the type of food that is available.  For example, many of the traits that the microbiome can affect deal with metabolism and the ability to store and use nutrients.  Quite a bit of the research I have been looking at recently leads me to believe that the microbiome likely helps us adapt to changes in the seasons in many ways, particularly by altering insulin sensitivity and increasing or decreasing metabolism.  It does this as the types of foods available from season to season change, and the types of foods we consume allow the proportions of different strains of bacteria found with in our microbiome to change as we provide a different environment within our inner "petri dish".  This is why a diverse array of different bacterial strains within our microbiome is important, it allows us to adapt to a wider variety of environments.  Our metabolic flexibility is largely dictated by our microbiome.

The epigenome allows an individual to become better suited to some aspects of the environment that are constant, but is able to change when the environment changes and becomes constant in another way.  Coupled with the microbiome, the epigenome likely has huge implications on your health and how you function from day to day as both can make you better at certain things based on how the environment interacts with these aspects of your genome.  You are, however, constrained by your coding genes.  You are not going to develop the ability to make an enzyme you've never been able to make.  Looking back at the termite at the beginning of this blog, if the termite were to somehow lose the microbes within it's microbiome that help it digest wood, it would be curtains for the termite.  In this way, the environment that your ancestors evolved in is also pretty important.

If you truly think about it, evolution is happening at all 3 levels of your genome.  Your microbiome is evolving based on the food you put in to your body, your cells are evolving as the microbiome changes the inputs to the epigenome which changes the inputs to your cells leading to different outcomes, and the human species as a whole is adapting as these other parts of your genome interact with the coding genes.  Furthermore, all 3 aspects of your genome allow you to adapt to the environment that you are in, in either a good way or a bad way.  With all of this talk about evolution and adaptation, it seems that a talk about evolution by natural selection is in order for the next blog.

Previous: How your cells work                                                                     Next: Evolution and adaptation

Monday, February 3, 2014

Health Research Recap (Week of Jan. 27, 2014)

Researchers studying mice found that fragmented sleep caused tumors to grow more aggressively by altering the immune system.  The researchers placed 2 groups of mice in cages that allowed them to either sleep uninterrupted or with constant interruption for 7 days and then injected them with tumor cells.  After 2 weeks, all mice had tumors that were felt and they were assessed after 4 weeks.  The tumors in the mice who experienced fragmented sleep were twice the size of those who slept uninterrupted and were more likely to invade other tissues when implanted in the thigh.  Sleep affects health in many ways, so getting good sleep should be high up on your list of priorities.

A couple of studies found that sleeping for short or excessively long periods of time is linked to symptoms of depression.  The first study was done in twins and showed changes in the expression of genes related to both sleep and depression symptoms based on sleep duration.  The effects were almost twice as large in twins who slept for less than 7 hours or more than 9 hours when compared to those who slept between 7-8.9 hours per night.  The other study showed a link between sleep deprivation and depression, but the study in twins is more interesting because it shows that putting the same genes under different environmental conditions can have a pretty strong affect on health.

Researchers found that people who ate a bad breakfast as adolescents were 68% more likely to have the metabolic syndrome 27 years later than those who ate a substantial one.  A poor breakfast was defined as either eating nothing or only eating or drinking something "sweet".  The characteristics of the metabolic syndrome that were most affected were abdominal obesity and high fasting blood glucose.  While the snap judgement is to declare breakfast the most important meal, I think the real issue is that people focus more on eating real food that is unprocessed and nutrient dense than when they are eating their food.

A study on the effect of contradictory nutritional information found that people who felt they had heard more conflicting nutritional recommendation were more likely to ignore them altogether.  Furthermore, they were more likely to ignore recommendations that were not very controversial and had total support such as eating more vegetables.  One of the trappings of using the type of data that most people base their recommendations on is that it is not very accurate, and it is unfortunate that the nutritional sciences pump out recommendations based on shoddy research.  Especially since it apparently causes some blowback that this study identifies.

A study on the psychological effect of labeling obesity as a disease found that obese people who read the message that obesity was a disease were less likely to believe healthy nutritional practices were important, were less likely to be concerned about their weight and had a more positive body image, and were more likely to select higher calorie choices from a menu than people who read the message that obesity was not a disease or a neutral message on the topic.  I personally am against the message that obesity is a disease, my opinion is that it is a metabolic state that increases the risk for disease.  I also believe the message that it is a disease is damaging in more ways than this study elucidates, but the most obvious is that making someone feel like their state is out of their control is not very motivating. Regardless, I believe a good body image is important, but not when it comes at the expense of someone's health.

A study on yoga found that female breast cancer survivors who practiced yoga for 3 months had 41% less fatigue and an approximate 12% drop in inflammatory cytokines than women who did not practice yoga.  Additionally, the same tests were run 3 months after the yoga class had finished and fatigue was 57% lower and inflammatory cytokines were approximately 17% lower in the women who practiced yoga.  The researchers believe the continued improvement once the classes were stopped was possibly from improved sleep quality, continued practice at home, or the women also could have taken aspects from the yoga classes such as breathing and meditation and applied them in real life.

A study found a two-fold increase in heart attack risk for men under the age of 65 at the onset of testosterone therapy.  In men over 65 and men under 65 with pre-existing heart disease, beginning testosterone therapy doubles their risk of having a non-fatal myocardial during the onset of therapy.  The study didn't look at the long term effects of testosterone therapy, but I think there is a place for testosterone therapy if done properly and in the context of an otherwise healthy lifestyle.

Dr. Michael Eades has a great post on the way pharmaceutical research is deceptively reported to inflate the effects of their drugs, check it out here.