Geoffrey Purcell wrote:
> If you read about the various famines in the last 60 years, you'll find that one of the big
> reasons why some underdeveloped countries have them so frequently is that they are
> too dependent on one or two
> staples(usually poor foods such as tubers, like cassava etc- cassava contains cyanogenic
> compunds so must be fermented, grated and left out in the sun so that the cyanide can
> evaporate, it also needs to be cooked beforehand, and has been linked to the deficiency-
> disease kwashiorkor.) The trouble with tubers is
> that they commonly have antinutrients in them, and are deficient in a number of key
> trace nutrients, so become a problem if consumed in more than trace amounts. The other
> point is that the DHA hypothesis holds that it's the DHA in meat that helps to increase
> brain-size(tubers don't contain DHA in remotely significant amounts, last I checked).
>
My question was, why would tubers only have been eaten in famine times?
These observations, while correct, don't answer that question. Virtually
all plant foods, including the paleo ones, have so-called "secondary
compounds" (toxins and antinutrients) to some degree, including
strawberries, peaches, spinach, broccoli, radishes, cauliflower,
cabbage, and collard greens--all of which contain goitrogens. Spinach
and rhubarb also contain oxalic acid, another antinutrient. So the mere
presence of antinutrients in foods doesn't make them either inedible or
nonpaleo. The fact that a given food, such as peaches, is devoid of DHA
certainly isn't sufficient to make it nonpaleo. There's no reason to
believe that these foods would only have been consumed in trace amounts,
despite the presence of antinutrients in them.
I ask this not because I advocate a tuber-based paleo diet, or because I
think tuber consumption is what drove the evolution of the brain. The
question is simply: Should a (modern) paleodiet include any tubers? The
answer to that questions is generally understood to be that a modern
paleodiet should include only foods that were a normal (not necessarily
dominant) part of the actual diet of paleolithic people. So the
question isn't, Did paleolithic people have a tuber-based diet. I agree
that the answer to that question is no. The question is, rather, Did
paleolithic people normally eat tubers, not as desperation famine food,
but as part of their diverse foraged food supply? I see no reason to
think that the answer to this question was no.
The difference between edible and inedible plants is that the edible
ones have lower levels of secondary compounds; they are not necessarily
devoid of them. Cooking lowers the levels of secondary compounds in
otherwise inedible plants to levels comparable to those in plants that
are edible uncooked. The only diet that would be devoid of secondary
compounds would be an all-meat diet (but no raw eggs!). While this is
certainly an option, I think nobody would suggest that a paleo diet
*requires* it. And since cooking (not just fire) extends well back into
the paleolithic era, to before the appearance of modern homo sapiens,
cooking is paleo. That doesn't mean that a paleo diet entails cooking,
but it does mean that it includes it. Cooking made more foods available
by making more plants edible, and it did so in indisputably paleo
times. So the "edible raw" criterion of paleo doesn't line up very well
with what actual paleolithic people were probably doing for the last
quarter million years or so.
Todd Moody
[log in to unmask]
|
