oxygenated food for the brain?

By Alison Campbell 18/08/2010

I was reading a couple about ‘raw foods’ today. This is ‘raw foods’ as in ‘foods that you don’t heat above 40oC in processing them.’ It’s also as in, a vegetarian diet. (I do rather enjoy vegetarian food & when we had a French exchange student staying with us that was pretty much all we ate, because that was what she ate & it must be hard enough being half a world away from home without having to live in a house of voracious carnivores. But I don’t think I could eat nothing but, all the time; I like meat too much.) Anyway, what caught my eye wasn’t so much the diet program itself but the mis-use of science to promote it. That did rather get my goat brocolli.

Apparently you should get your kids to eat their greens (along with the rest of the diet) by telling them that plants do this wonderful thing: they turn sunlight into chlorophyll & when you eat it – it will give you extra oxygen. Sigh… This concept was repeated in the second article, which told me that raw (but not cooked) foods are ‘oxygenated’ & thus better for your brain, which needs to be fully oxygenated to work properly. Well, yes, & so do all your other bits & pieces, & they don’t get the oxygen from food. As Ben Goldacre once said, even if chlorophyll were to survive the digestive process & make it through to the intestine, it needs light in order to photosynthesise, quite apart from the fact that you don’t normally absorb oxygen across the gut wall. And it’s kind of dark inside you 🙂

The second shaky claim related to digestive enzymes. Because raw foods are ‘alive’ then they are full of enzymes. And so we’re told that eating them will help you to digest your meals better.

Er, no. FIrst, because when said enzymes – being proteins – hit the low pH environment of your stomach they are highly likely to be denatured. This change in shape means that they lose the ability to function as they should, & in fact they’ll be chopped up into amino acids like any other protein in your food, before being absorbed & then used by your cells to make their own enzymes.

And second – the raw foods diet is plant-based. Yes, plants & animals are going to have some enzymes in common. I’d expect that those involved in cellular respiration & DNA replication/protein synthesis would be very similar, for example, because these are crucial processes in any cell’s life & any deviations in form & function are likely to be severely punished by natural selection. But we already have those enzymes; they’re manufactured in situ as required. In other words, even if the plant enzymes somehow made it into cells intact & capable of functioning, they’d be redundant. However, with a very few exceptions, plants aren’t in the habit of consuming other organisms so, in regard to plant cells being a good source of the digestive enzymes required to for the proper functioning of an omnivore’s gut – no, I don’t think so. No.

You might say, why on earth do you bother about this stuff? After all, it’s not doing any harm. But the thing is – science is so cool, so exciting; it tells us so much about the world – why do people have to prostitute it in this way? Kids (& others) are fascinated by the way their bodies’ organ systems work, and I can’t see why there seems to be a need to provide ‘simple’ – and wrong! – alternative ‘explanations’ when the real thing is so wonderful.