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Published: Sunday August 10, 2014 MYT 12:00:00 AM
Updated: Tuesday August 19, 2014 MYT 7:56:10 PM

The raw facts behind raw food

Before you embark on that raw food diet or go palaeo, consider the human evolution ... 

I FELT a little funny writing up this article – not funny in a ha-ha way, just a wry sort of funny, like the look between good pals who’ve spotted someone inappropriately dressed at the office party. There seems to be some consensus that eating raw food is the best way to remain healthy and overcome various ailments. There is probably some degree of truth in this – but also some bizarre misconceptions.

The uncooked idea

In a nutshell, one can say raw foodism is the maintenance of a diet of only uncooked and unprocessed foods.

There is also a slightly looser interpretation whereby food is still considered raw if it has not been cooked much above 45°C or even 40°C, depending on who you want to believe.

Mostly, people think that a raw food diet consists of eating uncooked vegetables, nuts and beans – but this is not strictly true. That definition may apply to raw vegans, but there are also raw vegetarians who can also eat uncooked eggs and unprocessed dairy products.

And there are also people who are on other raw food diets, like the raw Palaeolithic diet, which is based mainly on raw fish, raw meats and other plant roots and foods which they assume a Palaeolithic man would be eating a couple of million years ago.

First, let us please get one thing straight: there is nothing wrong at all with ingesting raw food, especially if it is organically produced. It probably does a lot of good to detox your body from the tonnes of myriad chemicals, salts, sugars and additives sadly present in modern processed foods.

The only thing is, one actually needs to be quite fit and healthy to start on a raw food diet in the first place. And if you’re sick, you really need to be at a reasonable level of fitness first for a raw food diet to help you. The reason is due to an odd fact: humans have relatively small digestive systems compared to other primates. To make this fact even more curious, humans actually have much smaller mouths and dental structures than other primates.

Why are these facts so peculiar? Let’s consider a pithy quote from a 19th century French gastronome, Jean Anthelme Brillat-Savarin, who said bluntly, “A man does not live on what he eats but on what he digests.”

To put it simply, if humans evolved eating only raw food, then the intestines would have needed to be much longer to extract more nutrition from what has been eaten (as for herbivores). In addition, human mouths and teeth would need to be much larger, to grind more food before ingestion.

The reason is that unprocessed food is usually pretty darn difficult to digest – try munching on a bag of kale or a cauliflower if you don’t believe me.

Nowadays, we have blenders and juicers to pulverise ingredients into a much more digestible mush before eating, but even so, the digestive effort will likely still be higher than if the food had been cooked.

It’s a little ironic that although food may have lost some nutrients during cooking, on balance, the primitive human body would always prefer cooked food because it is just a much more efficient way to obtain energy – and quick efficient energy is very important to survival in Palaeolithic times.

Cooking the calories

Talking about energy from food, one might be tempted to think in terms of calories. However, it is now clear that calories are not the same even between different preparations of the same foods. You can take practically any type of food as an example.

Let’s assume we have two identical twins. One eats 2,500 calories of cooked meat and vegetables daily. The other eats 2,500 calories of uncooked meat and uncooked vegetables daily.

The inability to fully extract the calories from the uncooked food will mean that the second twin will certainly lose weight within days compared to his twin. In addition, he would have to expend a lot of energy to chew the food fully so that he can even swallow it in the first place.

It is the same with other foods. The calories from a raw carrot is not the same as the calories from a stewed carrot – the nutrients would be different due to the cooking but even so, there would be more digestible calories from the cooked vegetable.

Something to chew on

So what conclusion can we draw from simply looking at ourselves? Why is our intestinal capacity so small? Why are our own mouths only half the size of a chimpanzee’s when fully opened? Why are our teeth so small? Why indeed are our jaw muscles so weak compared to other primates?

Actually, the answer to the last question is quite interesting because our small jaw muscles are due to a gene called MYH16, which started to spread amongst the homo habilis (Australopithecus habilis) species around 2.3 million years ago. That was about the time when the homo genus started to adapt to eating soft, cooked food.

Cooked food is softer to eat and very much easier to digest and hence our human ancestors started to have smaller teeth and shorter intestines. Cutting down the size of their intestines means less metabolic work was required and therefore their bodies can support other organs better – and the main beneficiary organ turned out to be the brain.

So from the homo habilis through to homo erectus to homo sapiens today, every new species has had a bigger brain than the previous. This is no coincidence – humans basically got smarter because their bodies can afford to support the brain, an organ which needs a lot of energy to maintain.

And because they got smarter, they figured out better ways to obtain food; for examples, from agriculture, keeping livestock, making cheeses, and etc. They also figured out better ways to extract energy from food; for examples, through food preservation, new ways of cooking, and new cooking utensils such as ovens, and etc.

There is further evidence from the fact that certain chemicals created during cooking, like acrylamide, have a lesser effect on humans, even though they are known to cause cancers in other mammals – so human bodies have also adapted to cooking compounds.

It would therefore appear that human beings and human intelligence have evolved together primarily because of the ability of the homo genus to process and cook food.

So here is the funny part:

Eating cooked and processed food is exactly what permitted the human race to develop to the current stage where people can actually afford to avoid cooked food. That’s because human ingenuity (due to our larger brains) has created machines that allow the instant pulverisation of fruits and vegetables into a drinkable mush which the body can digest more easily – without these machines, there is little chance that the raw food fad would have taken off in the first place.

Imagine chewing eight sticks of celery, five sticks of carrots, 250 grams of kale, three oranges and three apples and a couple of guavas for a meal every day (that’s a recipe from some juicing book, by the way).

So consuming pulverised raw food is a pretty good way to improve on nutrient intake – but it will be hard to make up the calorie shortfall compared to cooked food.

Therefore, almost certainly, anyone on a raw food diet will lose weight, which of course, isn’t always a bad thing.

Apart from losing weight, many people on such a diet also report a drop in their sex drive – which again is not necessarily a bad situation given the world’s endemic over-population.

The other funny thing

... would be the reaction if a Palaeolithic man actually somehow came back today to see a modern human painfully chewing raw meat and raw vegetables when there is a grilled steak, two vegetables and chips (with gravy) on the next plate.

He might scratch his head a little and wonder if all that extra brain matter has been worth the effort.

Of course, a raw food diet is probably well worth the endeavour for many modern humans, but a Palaeolithic mind might not understand immediately as he would have never seen an obese or overweight person in his short lifetime.

It’s possible we need rawism

Somewhere along the path of human evolution, we have been a little too successful at manufacturing more food and much more calories than our bodies need – but this hadn’t stopped us from cramming it all in, along with all the associated food chemicals, additives and preservatives.

The raw food movement may therefore be simply a reaction to the inordinate oversupply of calories and unnatural compounds that plague our food today.

However, one has to be sensible about certain extreme raw food ideas. One motivation for some raw food enthusiasts is the promotion of a good intestinal flora.

That is fine but somehow I cannot think it is such a great idea to drink unpasteurised raw cow milk as often suggested – ungulates crap a lot, their tails swing rather close to their udders and there is rather a lot of nasty bacteria around in all farms anyway.

And statistics show that people have been known to die or get rather perilously ill with raw milk, though to be fair the incidence is really not that high.

The other rationale is that somehow raw food can cure all sorts of ailments. Sorry – but it doesn’t.

If you are sick, go see a doctor and don’t rely on juicing papaya leaves or whatever for a cure. It is simply not worth the risk.

Ultimately, the simple facts are that raw food provides a boost in nutrients, and lowers the number of calories you ingest.

You know, one of the problems with fads is that people take them literally – and seriously.

It’s like falling in love – nothing can possibly be that bad about the new love. Everything the new love does is sweet and good and exciting.

Many people will even defend fads against the truth and perpetuate myths and falsehoods, either deliberately or unintentionally.

So be careful about people who’re evangelical about a fad – just because they believe it doesn’t mean you have to.

Raw food lovers live longer?

The irony about thinking that one can live longer by going back to prehistoric diets is that until about the 19th century, the average lifespan for a human being was at most 40 years – and this included people who could afford to eat very good cooked food, were literate and therefore more likely to be included in such statistics.

The poorer folk ate more or less a raw food diet and they died much younger.

But, then, they also didn’t have juicers or food processors.

There’s a joke in there somewhere ... but I’m about to juice up some carrots, and that is mainly because I’m overweight and prefer the taste of carrot juice once in a while.

Tags / Keywords: curious cook, raw food diet

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