Thomas Bridgeland wrote:

>On Monday, November 8, 2004, at 05:41 PM, Persephone O'Donnell wrote:
>> Many foodstuffs have complex cocktails of natural chemicals, not all of
>> which are nutrients, especially in plants where many were designed to
>> protect the plant from being eaten. I don't think it's safe to assume
>> that
>> a substance must have some purpose in the body just because it's part
>> of
>> something we can eat.


>My example was trans-fatty acids, which are found in milk and meat.
>Milk is specifically designed for a baby's growth. Nothing goes into it
>but what the baby needs. Animals as well produce in their bodies what
>they need to survive. Maybe we adults don't need any at all, maybe we
>do. But from a paleo perspective we are adapted to it either way.
>
>I think what you said is true as regards to plants.

Having always thought that trans-fatty acids are automatically bad for us,
I did some further research this morning. It seems that not enough
experiments have been done to say *definitively* that these substances
cause us harm. However,in excess, it looks as if they probably cause
damage to our cardiovascular systems and brains by becoming a structural
part of our cell membranes.

It also appears that the mother's diet is the source of human milk trans-
fatty acids, particularly hydrogenated vegetable oils, with dairy products
contributing relatively little. Man-made foods containing trans-fatty
acids have much higher proportions than natural food sources such as milk,
sheep, deer etc.

In a study in the early 1990's, it was discovered that Mainland Chinese
women had 0.22% of trans-fatty acids in their breast milk, compared to
7.19% for Canadian women.

Whilst it hasn't been proven that trans-fatty acids in breast milk are
actively harmful to babies, it has been shown that their *elevation* in
breast milk is at the expense of n-6 and n-3 essential fatty acids, and
these are important in infant growth and development.

So perhaps it is true that the infant can cope happily with the levels of
trans-fatty acids that are present in the breast milk of a mother who
consumes them from natural sources only.

Once again, it's the dose that makes the poison.

Unfortunately, because of our unnatural Western diets, many other things
are transmitted in breast milk that the baby doesn't need, but I agree
with you that a mother on an organic paleo diet would only produce milk
containing what is right for her baby.

Cheers,

Persephone

P.S. Thanks for the rest of your post about our ancestors. Very
enlightening!