In general, I recommend decreasing the amount of animal food that you are eating, but that
doesn't mean become a vegetarian, and trying to increase vegetable protein in the diet.
There are many wonderful forms of soy that you can use as vegetable protein, other beans
also.
There is a lot of controversy about soy out there and if you go on the Internet you can
find all sorts of paranoid articles about the dangers of soy.
And now there are some medical experts talking about the dangers of soy of being an endocrine
disruptor, promoting cancer and so forth.
The epidemiological evidence from Asia is extremely reassuring that populations that
eat a lot of soy regularly have better health, better longevity, and in particular lower
rates of hormonally driven cancers.
Japanese women on traditional diets have one of the lowest rates of breast cancer in the
world - if they move to other countries and adopt their ways of eating, western ways of
eating, rates of breast cancer rapidly go up.
Japanese men gets prostate cancer at the same rates as American men but the prostate cancers
in Japan are much less aggressive - there is a much lower tendency to leave the gland
and spread and be deadly than in America.
I think these are both effects of soy diets.
But Japanese, although they eat soy at every meal and they do so from infancy to old age,
they are eating whole soy foods in moderation.
They are not eating fractionated soy foods, they are not eating functional foods spiked
with elements of soy, and they are not taking supplements of soy isoflavones.
A lot of the products, if you look at the ingredients it will say soy isolate, or isolated
soy protein, those are fractionated elements of soy and we have no epidemiological evidence
about their safety or benefits.
I would advise avoiding products made with those things and that includes a lot of those
fake meats out there, you know fake hotdogs and lunchmeats, all things made with soy isolate.
There are a few that aren't: a brand called Tofurkey that makes sausages and sliced things
and the first ingredient is organic tofu.
So by whole soy foods I mean edamame, which are great, soy nuts, soymilk, tofu and tempeh,
those are whole soy foods.
I would stay away from products made with soy isolate, isolated soy protein, I would
not take soy isoflavones as a supplement, I wouldn't eat functional foods like cereals
or soups that have soy isoflavones added to them.
I think moderate, regular consumption of soy beginning as early in life as possible is
good.
With breast cancer protection, it seems the major effect comes in childhood and adolescence.
It's an effect of soy in the diet on developing breast tissue that confers resistance to breast
cancer throughout life, so that's an important message to get to kids.
I expect that the prostate cancer protection works the same way.
We don't know if an America woman suddenly begins eating soy in mid-life that she's going
to get the same benefits in terms of breast cancer protection.
If you look at these isoflavones, these so-called phytoestrogens in soy that have estrogen-like
activity, some of them if you take them in test tubes, some of them stimulate breast
cancer cells to grow and some of them inhibit them from growing.
I think when scientists look at that, this is cause for concern that some of these elements
might actually promote cancer.
But this is the way nature works and it tends to produce things that both push and pull
that have opposite effects on the same thing and when you put them in the body, the body
knows how to deal with them.
To me, I think whole soy foods in moderation are very beneficial for a lot of reasons and
I think that substituting them for some of the animal foods in the diet is a useful change.
You are getting a better fat; the fat in soy is fine, it's when you isolate this as refined
soy oil that it’s a problem of excessive omega-6s.
You are getting these hormonally active things that are beneficial, you are getting fiber,
you are getting a good form of protein, some slow digesting carbohydrate, for all those
reasons it is good.