Soy: Healthy or Dangerous?


Uploaded by drweil on 19.07.2012

Transcript:
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.