BY Alyse

To Soy or Not to Soy

From soy chicken cutlets, soy milk, and soy-based meat substitutes, to soy nuts, chips, soy-based energy bars, and protein powders…soy products are popping up everywhere!  This trend is secondary to the highly publicized research on soy’s health benefits.  Before overstocking your shelves with soy products, read on to learn about potential soy dangers and how much soy may be too much.


What caused this surge in soy-fortified products?
As soon as the media labeled soy the new “food cure”, soy products became the craze. The hype about soy’s benefits reached its pinnacle in the media after clinical evidence was published suggesting that including soy protein in a diet low in saturated fat and cholesterol may reduce the risk of coronary heart disease (CHD).

As a result of these studies, the FDA approved the health claim that soy protein plays a “role in reducing the risk of CHD.” This approval allowed for soy foods and beverages to have the claim on their label if they were low in fat, saturated fat, and cholesterol and contained at least 6.25 grams of soy protein per serving (the amount that is one-fourth of the supposedly effective level of 25 grams per day). It was also this health claim that lead food manufacturers to fortify an enormous number of food/beverage products with soy, in the hopes of making money off its new popularity.

A few other health benefits associated with soy, which further influenced its popularity, include:

  • Soy is rich in isoflavones- potential weapons against some cancers.
  • · Soy contains antioxidants, which protect cells from damage by free radicals. 

Given that heart disease is the number one killer in America, eating mass quantities of soy is a great idea, right? Wrong!

While the results of some clinical trials suggest the possibility of lowered total cholesterol, LDL, and triglycerides as a result of consuming soy, other studies do not reveal such positive effects. In fact, in late 2007, the FDA announced it was reevaluating the evidence in support of the health claim for soy protein and CHD.

Here is a list of some possible risks of consuming excessive soy:

  • May block the absorption of beneficial minerals
  • May inhibit certain enzymes
  • May inhibit thyroid hormone synthesis
  • May disrupt endocrine function
  • May increase allergic reactions (far more common than from other legumes)
  • May increase breast cancer risk; increasing consumption of soy, especially when you haven’t been consuming it your entire life, definitely does NOT have a preventive effect against breast cancer, as once believed. Researchers found that women consuming soy protein isolate actually had an increased incidence of epithelial hyperplasia, a condition that presages malignancies. Also, breast cancer survivors may be at higher risk of tumor recurrence because of the estrogen-like effects of soy.

Furthermore, while some studies boast that Asian women suffer far fewer cases of breast cancer than American women do because of their soy consumption, the hype neglects to point out that these Asian women eat a diet that is dramatically different than their American counterparts. The standard Asian diet consists of more natural products, far less fatty meat, greater amounts of vegetables and more fish.

Finally, some research has shown reduction of some peri-menopausal and menopausal symptoms such as hot flashes as a result of soy consumption, although other studies show inconsistent results.


Including soy products in your diet can be healthy. However, stick to the natural soy products, such as soybeans (edamame), tofu, tempeh, and soy sauce. Skip the soy fortified foods and beverages (bars, chips, powders, puddings…) and soy supplements, especially products with soy protein isolate. If you didn’t eat soy products on a regular basis growing up, DON’T start mega-dosing on them now. A balanced diet that includes 1 or 2 servings of soy a day is a good idea, as long as it also includes plenty of vegetables, fruits, whole grains and beans or other lean protein sources. However, women at a high risk for breast cancer or who have had breast cancer may want to limit themselves to no more than a few servings a week.

As for soy’s effect on reducing CHD risk, although it may be beneficial, there are numerous other ways to decrease CHD risk without any of the potential adverse risks of soy. These include increasing soluble fiber, fruit, vegetable, poly- and mono-unsaturated fat intake, decreasing saturated and trans fat intake, reaching a desirable body weight, and engaging in daily physical activity.