Monday, December 23, 2013

Health Research Recap (Week of 12/16/2013)

A trio of studies on gut bugs provides some interesting insight in to the inner workings of the microbiome.  The first study found that extreme diets that focus on either animal or plant matter exclusively can change the microbiome very quickly.  The researchers found a shift in the microbiome  within a day of switching to the all animal diet.  In addition to changing the composition of bacteria within the gut, it also changed the gene expression patterns of the bacteria that were there.  One interesting finding of this study is that the all meat diet increased the amount of a type of bacteria associated with inflammation.  This confirms initial findings of the Human Gut Project that show that people who eat a Paleo diet typically have higher amounts of bacteria associated with inflammation.  This study is very interesting and provides a lot of usable information for a project I am currently working on.  However, you have to take this data with a grain of salt.  Each diet was at the polar end of a continuum and most people eat somewhere in the middle.  You also have to take in to consideration that the inflammatory bacteria are beneficial in this scenario.  You don't want to be myopic when looking at the microbiome, it is highly likely that each type of bacteria is in there for a reason and they increase in proportion to provide metabolic flexibility to the host.  The agreement with the findings of this study and the Human Gut Project on the Paleo diet pretty much confirms a theory that I have that most people eating a Paleo diet are eating far more meat than vegetables, which I don't believe to be a good thing if you want to maintain metabolic flexibility.

The next study showed how the microbiome helps prevent bad guys from causing problems.  The study found that mice that were bred to not have gut bacteria are more susceptible to infection than mice who had an intact microbiome.  The mice were exposed to Listeria infection and within 24 hours the germ-free mice had 10,000 times more of the bacteria in their small intestine and 1,000 times more in lymph nodes that surround the small intestine than the mice with a microbiome.  The most interesting part of this study is that molecules that help regulate gene expression, called micro RNA, were lower in the mice with a microbiome than the mice that were germ-free.  This indicates that these miRNA are the mechanism that Listeria use to infect the host and having a microbiome is necessary to prevent this step and fight the infection.

Another study looked at the effects of Bacteroides fragilis, a microbe found in the gut of humans thought to be related to autism, in mice.  In mice that were bred to model autism, researchers found that dosing the mice with B. fragilis caused a reversal of some of their autism-like behaviors.  The mice also had a reversal of GI symptoms associated with the disease.  I've heard quite a bit about this particular strain of bacteria lately, and most of it seems to be in autism research.  As with all microbiome research, it is likely not as simple as taking a probiotic strain and you are cured, most diseases are multi-factorial and require a multi-factorial approach.

In other autism news, researchers found that children with autism respond well to peer solicited interaction.  Under normal conditions, kids with autism are less likely to engage other children in play than children without autism.  When the interaction was engaged by other children, children with autism played in the same manner as children without it.  This can be beneficial in multiple ways.  First, it is important for children with autism to learn about social interactions and this does that.  In addition, the study found that children with autism had higher levels of the stress hormone cortisol than children without it.  Exposing them to this stressor over time should help them learn to modulate the stress response and dampen it's effects on their ability to be social, just like exposing people to the stress of exercise helps them grow stronger.  This study also shows, in my opinion, that children with autism aren't anti-social, they just don't understand social interaction as well as children without it.

A study found that it's cheaper to bribe kids to eat fruits and vegetables in school than to just let them throw them out in the trash.  Forcing schools to give children fruits and vegetables in the hopes that they will eat them led to a minor increase in consumption.  In other words, most are thrown out.  Giving kids cold hard cash(It was actually small amounts of change) led them to consume 80% more vegetables than they otherwise would, regardless of the amount of money they received(Where were you 30 years ago?).  It appears a week of doing this didn't lead to a permanent change in habits, so the researchers want to redo the experiment over a longer time-frame to see if they can get the habits to stick. You may be wondering how it would be cheaper.  This new policy of giving more fruits and vegetables increased spending for lunches by $5.4 million, the kids end up throwing away $3.8 million of that.  Also, this would save us a fortune on the back-end in healthcare costs associated with the Standard American Diet.

In another study on eating habits in children, a study found that food selection choices by children mirrored those of their elders.  The diet of parents as well as grandparents had an effect on the food choices of children, but it also worked the other way around.  This study illustrates how food can have an effect on other generations, both good and bad.  The takehome message for parents should be, "Monkey see, Monkey do", so eat your veggies if you want your kids to.

I'm not going to spend a lot of time covering this one because it belongs in the pile of "No-duh" studies.  Food advertised during children's programming is nutritionally inferior to the food advertised during adult programming.  This certainly doesn't bode well for developing good eating habits at an early age, but putting your child in front of a television for multiple hours a day is probably not good in any way for their overall health.

The Type 2 diabetes drug Metformin provides only minor benefits in obese children who are also following a diet and lifestyle modification program.  Somehow I don't think this is going to prevent them from recommending it anyway.  In my opinion it's not worth the potential side effects for a minor benefit that could probably be achieved with more lifestyle modification.  The best way to fight obesity is to prevent it in the first place, and I don't believe it's caused by a Metformin deficiency.

A new study in nutrition fails to find any benefit in taking multivitamins for health.  This comes as no surprise to me, nature seems to have packaged food with nutrients and cofactors that enhance effectiveness and absorption.  A perfect example of this is vitamin C and bioflavonoids packed together in citrus fruit that work synergistically with one another in this way.  Another trap you fall in to when looking at nutrition as a bunch of isolated nutrients is the assumption that we've identified all nutrients that are essential to human health.  We know about vitamins because deficiencies in them lead to diseases of deficiency that occur relatively quickly, but that doesn't mean we've identified everything we need to be healthy.  Cancer could potentially be caused by a deficiency of nutrients that activate cellular antioxidant pathways, hence broccoli's potent anticancer benefits.  These are just a couple of the many reasons why you should rely on food and not supplements as your primary source of nutrients.  One thing of note, I do not agree with their recommendation of whole grain breads.  Processed food is processed food no matter which way you cut it, whether it comes from whole grains or not.  If you want to eat whole grains, eat them in their natural form and soak or ferment them.

It appears that the health risks associated with smoking tobacco are epigentic in nature.  A new study found changes in genetic expression associated with health problems that are common in people who smoked, but none of those changes occurred in people who used smokeless tobacco. This points to the act of smoking as being detrimental to health, and not specifically to the use of tobacco.  Of course, this does not exonerate tobacco as being healthy, just that many of the negative things related to it are due to smoke entering the lungs.

Finally, a bonus gut bugs study.  Children who grow up with household dogs are less likely to suffer from allergies than children who grow up without them.  This study compared mice previously exposed to dust from houses without dogs and those exposed to dust from houses with dogs.  Exposing mice to the dust from houses where dogs live caused a change in their microbiome and lowered their immune response to common allergens when compared to mice who were exposed to dust from houses without dogs.  The researchers found higher levels of a strain of bacteria called Lactobacillus johnsonii in the mice exposed to dust from houses with dogs.  When they exposed mice to only this specific strain, they found a dampened inflammatory response in the lungs as well suggesting this particular strain is important for proper lung function.  However, just exposing them to L. Johnsonii did not have as strong of an effect as exposing them to dust from houses with dogs, further strengthening the argument that the entire microbiome and not just singular strains found within it is responsible for optimal effect.