I would like to add a few precisions on the subject.

First, the goal of the article I mentioned was to find out the best way to
prevent vitamin A deficiency in underdeveloped countries. The conclusion of the
authors was:
 -vegetables (at least in the way they were prepared) do NOT raise serum vit. A
levels AT ALL.
 -beta-carotene supplements do
So, the conclusion was: if you want to reverse vitamin A deficiency by diet
alone, animal sources are much more efficient; but vegetables consumption
shouldn't be discouraged, since they provide other health benefits.

Now, a few questions might arise.

Q: Vitamin A in large doses is known to be toxic, but beta carotene isn't. Does
it mean that body regulates the amount of vitamin A in its system and produces
only as much as it needs to from the available carotenes, and thus that
vegetable sources are the best?

A: It's true that vitamin A in excess is toxic, but it's unlikely that you can
reach excessive levels of it by diet alone. Problems arise when you take
supplements (i.e. pills). It's also true that excesses of beta-carotene won't be
converted, but the problem is: diet rarely provides an excess of beta-carotene,
since the absorption is poor. On the other hand, supplementation by megadoses of
beta-carotene is well-absorbed and safe.

Q: Particle size on uncooked foods is particularly important; pureed or finely
chopped vegetables yields considerably higher beta-carotene absorption compare
to whole or sliced raw vegetables. Does it mean that poorly chewed food is not
well absorbed?

A: That's what I would think, since people who eat cooked food usually aren't
used to chewing enough, but I can't support this assumption by actual data.
Nevertheless, well-chewed (or finely chopped) vegetables are still poorly
absorbed.

Q: Mild heating, such as steaming, appears to improve the extractability of
beta-carotene from vegetables and also beta-carotene bioavailability. Does it
mean we should cook our carrots?

A: That's a complex question. With light cooking, you greatly increase the
amount of beta-carotene, and you lose variable percentages of vitamins, as well
as enzymes. I don't know much about the impact of enzymes on human health.
There are some specific diseases associated with vitamin A deficiency; but not
with enzyme deficiencies. Well, maybe scientists will one day discover the
benefits of raw carrot enzymes, who knows? As for toxicity of steamed carrots, I
am not sure that Maillard molecules pose a great health risk at steaming
temperatures. As I said in another post on this list, they are  problematic
mainly in meat and fish cooked at high temperature, when in the presence of
creatine they form carcinogenic compounds known as "heterocyclic amines".
Probably steamed carrots are "safe".

One of the big questions is: what are the advantages of eating raw? What are the
advantages of cooking? The more you think about it, the less clear the picture.
When examining the question of beta-carotene and other vitamins, clearly
excessive cooking is bad; but with light cooking, on the one hand, you lose a
little, and on the other hand you get more beta-carotene. Certainly, I don't
think it's necessary to cook carrots (I am currently 97% raw and I don't cook my
carrots), but it doesn't seem clear to me which one is best: 100% raw carrots,
or 50% raw and 50% cooked.

Q: How much do we really need, anyway?  Are any raw fooders really deficient in
carotene?

A: Well, are cooked fooders (in the US), provided they have a reasonably varied
diet, really deficient in vitamins? I don't think so. The RDA recommendations
have been established to prevent deficiency diseases, such as scurvy or
beri-beri, plus a safety margin. Now, exceeding the RDA probably has some
additional health benefits. We know that megadoses of antioxidants (vit. C, E,
Beta-carotene) are useful for people who suffer from heart disease. Now, of
course, you will ask "are any raw fooders suffering from heart disease?"
Moreover, the vitamins you get by diet alone will always be far below megadoses,
but the main point is: even if you don't have visible signs of deficiency, an
increased vitamin intake could (perhaps) improve your health.

Now, I don't think any vegan raw-fooder eating carrots regularly will ever
suffer from vitamin A deficiency; but he will certainly get less vitamin A than
someone who eats *some* steamed carrots; and the latter will get less vitamin A
than someone who eats animal sources of vit. A.

I am not trying to tell raw vegans to start eating animal food, or cooking
carrots. Probably beta-carotene intake is fine enough. Just:

 -don't think that because you eat raw you get more vitamins. Some vitamins are
more extractable and more bioavailable after light cooking.
 -don't think that because you eat plenty of carrots you get plenty of vitamin
A. You certainly get some, but not a huge amount.


Finally, I would like to thank Mary J. for her comments. I have no specific
answer about her questions. None of my sources mention candida, so I suppose
candida doesn't interfere with beta-carotene absorption.

Best wishes,

Jean-Louis
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