As it seems to happen with almost everything, nutrition advice and news aren’t exempt from scandal, innuendo, and misinformation. For years, without the scientific backing, scientists and researchers were convinced soy consumption helped prevent breast cancer, taking their conclusions from the fact that women in Japan, China, and Singapore, where soy is a diet staple, had much lower rates of breast cancer than women in the States.
Fast forward to a study published in 1996, in which soy isoflavones and soy proteins – both contain compounds similar to estrogen (however much weaker) – were found to stimulate the growth of abnormal cells in breast tissue. Another 1998 study drove the soy fear home when a particular strain of mice that received high amounts of isoflavones for a period of time developed breast tumors. The alarm bells went off and soy was blacklisted from many women’s diets.
The first study results were based on fluids extracted from women’s breasts comparing two groups – women who ate no soy, and those who ate 37 grams per day – for six months. The problem is, measuring breast fluid is incredibly tricky. And results are not reliable.
In 2013, Professor Gertraud Maskarinec put soy up to the test, but instead of concentrating on fluids, she took into account breast density (denser, more fibrous breasts are more apt to develop cancer, and the common progestin/estrogen combo given to women post menopause ups the level of breast density). After studying 82 women – half receiving two servings of soy each day, and the other less than three servings per week during six months – and neither group showed a change in breast density. Furthermore, Professor Maskarine debunked the mice studies, as mice metabolize isoflavones very differently than people. Though the mice developed tumors, people won’t.
Soy, a mainstay of many Asian diets, has proven time and again to be a defense against breast cancer. In fact, a US study that tracked women with breast cancer over a course of seven years found that those who consumed a minimum of 10 grams of isoflavones daily were 24% less likely to have a recurrence.
So, what’s up with soy? Soy is a great source of protein, good fats (monounsaturated, polyunsaturated and omega-3 fatty acids), calcium and iron. It’s time to bring soy back into our diets!
Replace high fat animal products (meat and milk) with soy products by using Tofu (firm or extra firm) in soups, pasta sauces and stir fry vegetables. Silken tofu is great to use to prepare dips, shakes, soups, and sauces. This is a great way to heart health while not skimping on the proteins our bodies need!
Add soybeans to salads, soups, sauces and pasta to give your meal an extra soy boost. Or buy edamame (green soy which is divine) and steam and lightly salt to eat as a snack!
Soy beverages are great to use to make pancakes (replacing milk), oatmeal, add to tea or coffee, adding the creamy flavor you’re looking for. Make sure you buy a plain beverage (not sweetened or flavored) that is fortified.
Two or three servings of soy per day (approximately 20 – 24 grams) would be consistent with what is consumed in Asian diets, where it’s been proven to be beneficial. Plus, it adds pop and flavor to the tried and true recipes we’ve grown up with! Registered dietitians breathe a collective sigh of relief to be able to take soy off the black list and recommend clients put it on their shopping list.