Soy has been getting soy much attention lately,
and there’s a lot of conflicting information out there. Let’s start with ”What is soy?” Soy is in the legume/bean family that’s native
to southeastern Asia. Although it’s been part of the Asian diet for thousands of years,
soybeans were only introduced to America about two hundred years ago. Now, the U.S. states
produce about half of the world’s supply of soybeans. Soybeans contain 35 to 40% protein. These
soybean proteins are complete which means they contain significant amounts of all the
essential amino acids our bodies need but can’t make on our own. That’s why soy protein
can be a great substitute for animal-based protein that have complete proteins too but
also contain more fat, especially unhealthy, saturated fat along with cholesterol. For such a tiny package, soy is a dietary
powerhouse when it comes to biological action. That’s because soybeans are uniquely rich
in certain bioactive molecules called isoflavones. Isoflavones can function as an anti inflammatory,
an antioxidant (counteracting the damaging effects of free radicals in our cells), and
they can even kill parasites! There are different forms of isoflavones.
Some forms are more bioavailable, which means our bodies can use them more easily than others.
Most traditional Asian soy foods generally contain more of the bioavailable kind than
do Western foods Isoflavones are found in a number of plants
besides soy, like fava beans, and even in coffee! You can find a lot of products made
with soy, but watch out for processed soy foods. Though usually high in protein, they
typically contain lower levels of isoflavones. In addition to any possible biological action
from isoflavones, many soy products are believed to be healthy. That’s because of their high
content of polyunsaturated fats (the good kind), fiber, vitamins and minerals, and their
low content of saturated fat (the bad kind). Eating soy foods might lower the risk of heart
disease, type 2 diabetes and certain cancers like breast and prostate cancers, as well
as improve bone health and give relief from menopausal symptoms. Now I’ve got your attention,
right? Well, you and millions of other people, But if you dig through all the medical literature,
you’ll find that it’s complicated and it hasn’t all been sorted out yet.
Bottom line: If you’re using soy protein to replace artery-clogging animal protein in
your diet, then you’re switching out saturated fat and bad cholesterol for a wiser protein
source. That’s a good idea. But if you’re hoping to stave off heart disease with small
amounts of processed soy or soy supplements, the benefits are much less certain.
And if you’re looking to soy protein or isoflavones to improve menopausal symptoms, postmenopausal
bone loss, prevent or treat breast and prostate cancers, a lot more research needs to be done
before a strong recommendation can be made. As part of a balanced diet, it’s soy good.