Wednesday, August 1, 2012

A small primer on Genetics, and its implications for a Paleo diet and lifestyle.

This blog has been dormant for long. From now on I will be making an effort to keep the articles flowing.

I heard this question from a person, who thought that since our digestive system adapts to new food we should be able to adapt to chemicals in our lifetime. This is grossly erroneous. This article will attempt to explain why it is wrong.

There are several questions on why to use a Paleolithic Diet. Paleo diet gurus say that there has been very little evolution since the start of the Neolithic Period. While Scientists say that the rate of evolution has quickened since the advent of Agriculture.

Which one is to be believed?

I would side with the scientists. Yes evolution has quickened with the advent of agriculture. And it must be so, because a changed environment (eating habits) necessitates adaptation. This would increase the pace of evolution. By this logic the pace of evolution must be maddening in the present century. And it must be so. You must be hearing news of increased cases of birth defects :-).

Evolution does not involve only good things. It can create adaptations that are good only on the average. For example Sickle Cell anaemia. It evolved for enabling adaptation to malaria. It is not a good adaptation. Some people get too much of it, that is it becomes the dominant factor then it can cause a much increased mortality. Faster adaptations are generally a trade off.

Over time evolution will find a way to solve a problem that does not have any bad side effects, but this takes a very long time.

Remember that evolution is measured in generations, not in time. So a species like humans who have a very long time between generations (20yrs), will take a long time for the same evolution, as bacteria, where the time between generations is measured in minutes. Bacteria can also evolve by direct DNA transfer, so they don't even need a generation.

Now lets consider another question. Is it really genetic adaptation we see in the nature? Do you know that genetic difference between Chimpanzees and us is less than 1%. So why are we so different than Chimpanzees.

The answer is really Epigenetics. Epigenetics is responsible for most of the genetic conditions that we blame genes for. And the good news is that you can affect epigenetics with your lifestyle.

So what is Epigenetics?

Genes are basically recipes for creating proteins. The Nucleus can be considered to be a huge dynamic library of such recipes. The infrastructure used to organize the library is called epigenetics. There is so much genetic information in the nucleus that it would not be possible to make everything available efficiently. So the library arranges itself to provide the most used recipes in the most efficient way.

If you use different recipes the organization will rearrange to allow the new access to be made more efficiently. This rearrangement can take a long time, even generations.

An important caveat is that the reorganization can only help with conditions that have already been encountered before. It cannot help with new conditions. That is where mutations are required for experimenting with the new conditions. And adapting to a new condition takes a much longer time than adapting to a condition that has occured before.

When you eat modern processed foods, the body is struggling to work with them, many of the chemicals in them, it has never encountered before. It does not know what to do about them. They can and do confuse the system.

When you eat neolithic foods, ie grains/legumes/milk, the body knows how to handle them, although the handling may not be entirely good. Some people may react to them badly, eg Coeliac disease, some may handle them sub optimally, ie gas, bad digestion, others may be able to handle them perfectly well.

With paleolithic foods, chances are that the foods themselves have evolved so much, and have created proteins and ezymes that we cannot handle, but mostly they will be handled very well. Allergies to paleolithic foods are rare, but not rare for neolithic foods. With Modern chemicals, the system does not even know how to react. They mostly cause damage, without system reacting to them.

The good thing is that epigenetics can allow us to reverse that bad effects of the modern foods, if the damage is not extensive.

One more important point is that our digestive system is very much dependent on our gut flora, ie the bacteria and other microbes in our digestive system. The microbes do adapt very fast to new inputs, so the digestive system adaptation is very fast, but this doesn't mean that our body will be able to absorb or discard the modern chemicals correctly. They can still enter our system. They can and will still cause damage to us.

The best option is to start a strict paleo diet for a couple of months, then slowly add neolithic stuff, to determine whether we are able to handle them well. Avoid the modern processed stuff completely. That stuff should not even be part of food.

When you eat a good diet that your body can handle well, you will see marked improvement in your well being, as the epigenetic structure will align to where it should be, slowly over time.

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