Monday, October 27, 2008

Thanks Mr Cannibal

I remember reading a news report some time ago about how worried people in Germany were about Creutzfeld Jacob disease. It was actually making a lot people sick with worry yet at the time statistics showed that not even one person had come down with the disease inside Germany. Creutzfeld Jacob disease was going to become the new AIDS - which by the way didn’t turn out to be as bad as was predicted but that’s another story. Scientists certainly made the disease look like it had the potential to become a major problem with its long incubation and widespread entry into the human food chain from dodgy animal feeding practises.

Now below I mention that our pre-historic ancestors probably indulged in a lot of cannibalism. This is a direct result of our intelligence strangely enough as intelligence can easily over-ride innate instincts that largely prevent such repugnant behaviour from occurring. From a pre-historic person’s point of view it makes a lot of sense to eat the flesh of humans rather than just let it go to waste. It tastes a bit like pork apparently which is a favourite of all primitive people. Also it is likely that humans didn’t even consider humans from other tribes to be of the same species. Even in recent times it has been common for human races to consider other races to be somehow sub-human and closer to animals than themselves. There have been reports from the Congo of rebels hunting and eating pygmies as if they are food animals for example. The widespread occurrence of cannibalism amongst primitive peoples across the planet implies that it has been very common throughout human history. Evidence gathered from bio-chemical analysis of fossilized human faeces and the cuts and scrapes found on human bones all suggest widespread cannibalism.

Well it turns out those Germans didn't need to worry because cannibalism might have saved us from an epidemic of Creutzfeld Jacob disease or other prion diseases. It appears that most humans are protected from prion disease and the only explanation is that we have been selected to survive such diseases. Our ancestors indulged in so much cannibalism that we all now possess genes that protect us from the unhealthy effects of cannibalism.

Widespread cannibalism may have caused prehistoric prion disease epidemics, Science study suggests:

Human flesh may have been a fairly regular menu item for our prehistoric ancestors, according to researchers. They say it's the most likely explanation for their discovery that genes protecting against prion diseases -- which can be spread by eating contaminated flesh -- have long been widespread throughout the world.

The genes, which are mutant versions of the prion protein gene, show key signs of having spread through populations as the result of natural selection, the researchers report in the journal Science, published by the American Association for the Advancement of Science. Such mutations, or "polymorphisms," could have provided prehistoric humans a better chance of surviving epidemics of prion diseases, similar to modern day diseases such as Creutzfeld Jacob disease, or kuru.

Friday, October 17, 2008

Stomachs and Evolution

The closest relatives of humans are the chimpanzees and bonobos. Bonobos are almost identical to chimps yet have a very different social structure, temperament and diet. It almost looks like humans are a mix of chimp and bonobo with added intelligence thrown in. Chimps eat mostly fruit augmented with protein and fat from insects and any smaller animals they can lay their hands on. Bonobos eat a lot of vegetable matter much like gorillas do. This is because they live south of the Niger River where there are no gorillas. Not having to compete with gorillas has resulted in them developing quite differently to chimpanzees. A diet consisting mostly of vegetables with fruit has resulted in a society where the leaders are females and empathy and sexual orgies abound – one female bonobo was observed copulating fifty times in one day. Ok, I’m digressing now.

The digestive systems of primates vary quite markedly. Chimps, bonobos and gorillas have large colons whereas humans have smaller colons but more volume, proportionally, in the small intestine. The overall gut volume in humans, on average, is proportionally smaller than the other high primates. This implies that humans have adapted to eating higher caloric and easier digested foods. The digestive tracts of the other primates are adapted to eating more vegetable matter that requires a higher degree of processing. Humans have adapted to eating high quality food that is mostly absorbed by the small intestine. In the pre-agricultural era this food would have been meat and starchy roots augmented with nuts and fruits. Selective pressures resulted in an animal that had a smaller gut volume relative to body size. A smaller gut is probably advantageous when running down prey. Predators tend to have smaller abdomens than herbivores.

Today we have greatly increased the ‘quality’ of food. Fruits and vegetables bear little resemblance to their ancestral originals. Fruits and vegetables are packed with sugars that we also extract and refine to produce super foods. Unfortunately we still have a cave-man type of mindset that eats when food is available – especially high carbohydrate food that doesn’t elicit a full response when enough has been consumed. The reason for this is unclear however such foods are so unnatural that we probably haven’t had enough time to adapt to nourishing ourselves with them. The future may well see a human with very small intestinal volume that matches the quality of food taken. We are already starting to do this now with surgical intervention. Stomach reduction surgery is now a very common method of controlling obesity.

Perhaps we will need to consider reducing the gut volumes of new born humans in order to prepare them for an environment where food is available in lethal quantities. If we don’t evolutionary forces will do it for us anyway. Already the epidemic of diabetes and other diet related diseases are working on adapting the human body to the new diet regime by killing off and reducing the fertility of individuals who cannot control their eating impulses. Diabetes and obesity is inflicting individuals at ever younger ages these days and looks set to continue. The survivors will be those most able to optimally process the high caloric foods that abound today.

Thursday, October 16, 2008

Mind Games

You’ve heard it said, maybe a million times, we are creatures of habit. The road to a healthier lifestyle is simply about breaking the bad habits and developing good habits. Once a habit has become established it becomes second-nature and no longer a struggle. A personal example is my habit of not eating breakfast and only eating a piece of fruit and something high protein like sardines for lunch. This has now become so ingrained that I never feel like changing the regime and if I do it is a bit of a struggle.

The problem today is that people have acquired a plethora of bad habits. They do things that are bad for their health without even thinking about it. What was once a rare treat is now part of the daily regime, which is a shame in that rare treats are now, well, rare in themselves. I remember when cashew nuts, fruit juice, restaurant meals and chocolate were great luxuries.

At the end of the day success depends on the outcome of the mind game. Unless you are very lucky a persistent and consistent approach to life is absolutely necessary to achieve your goals. The reason for this is because this is the only way to develop a habit. A habit is analogous to regularly putting money in the bank – a little by little great things can be achieved over time. It is essential, of course, to identify what are bad habits and what are good habits. The analogy of the bank can be applied to eating but in a bad way. People eat just a little too much each and everyday and before they know it (literally) they have a very impressive store of fat. This didn’t just happen over night. No, no, no this is the result of years of over eating every single day.

When I look at the general condition of people I see walking around the mall it strikes me that most people have become misshapen, many grotesquely so, as a direct result of poor eating habits. Other habits, too, have contributed to this freak show such as smoking, drinking and shunning exercise but far and away the single most contributing factor is a poor eating habit. Not a single day passes that I don’t spy a person walking by and think to myself, why, why, why have you done this to yourself? Isn’t your body the most precious thing you have?

Yet the solution is so simple - win the mind game by developing good habits.