On Tue, 15 Dec 1998, Ilya wrote:

> An equal,
> if not more plausible explanation, is that people all started out as either
> allergic or sensitive to some foods. Then, as a partucular culture used
> that food, over centuries the members that were more sensitive died out.

This is adaptation.  Note that it works in the other direction as
well.  When a population is no longer making extensive use of a
particular food, lack of tolerance for that food is no longer
very disadvantageous, so the genes/mutations that cause that
intolerance can increase.

This means that we cannot assume that once people adapt to a food
they stay adapted to it.

> So what you have now is some genetic variation amongst people that is greater
> than what we had during paleo times.

Yes, I think this is exactly right.  The more diversity in the
food supply of subpopulations, the more diversity in adaptation.

> This does not mean that the people
> living today are totally adapted to these non-paleo foods. Just their
> sensitivity tends to be much less.

I don't think the concept of "total adaptation" has any definite
meaning, either for paleo or nonpaleo foods.  If we find that a
population using X foods is generally as healthy as another
population using Y foods, then it is reasonable to conclude that
the two populations are equally adapted to their respective
foods.

> So your Swiss mountain folk might
> be doing fairly well on bread, cheese and meat, but might do even better
> without bread and more veggies instead.

Possibly, but it's also possible that as you introduce veggies
that these people have not been eating with any frequency you
will discover intolerances that have not had a chance to be
weeded out.

> Sometimes, this natural selection
> may be very rapid. If, during the times of famine, all the entire tribe eats
> is bread then very quickly all truly sensitive individuals die off.

Exactly.

> Then,
> the tribe can increase the intake of bread because there are fewer obvious
> reactions even in the times of plenty. Over a few centuries the impact of
> bread could be much smaller than on a totally unadapted person, but to say
> that there is non, or that one should not avoid them is a stretch.

I would argue that it is also a stretch to say that even though
they appear to be quite healthy, the Swiss mountain folk have a
*hidden* intolerance for the bread that they eat in large
amounts.  However, I do think it would be a stretch to conclude
that because this diet works for the Swiss mountain folk it would
also work for everybody else.

> Another point I would like to make is believing stories about out of the
> way poorly researched cultures. Many of the statements about them are
> utterly untrue.

I agree, and I think this is also reason not to rely overmuch on
any single information source, such as Vilhjalmur Stefannson or
Weston Price.  As has been often pointed out, there is bias in
research.

Todd Moody
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