What I Choose to Buy at the Co-op... and Why

What's the Scoop on Soy?

by Loretta Gillen, Nutrition Committee

#6 in a series of monthly articles from members of the HWFC Nutrition committee

Many of us know that soy products have been cited for many potential health benefits and risks. The benefits include hearthealthy components (lowering of cholesterol), help with menopause symptoms for women, balancing blood sugar imbalances and reduction of certain cancers. Over-consumption of soy, especially in concentrated forms, have been found to be potentially harmful. It is potentially harmful for women who already have estrogen-based breast cancer to consume large amounts of soy products. In essence, soy has both a light side and a dark side.

Soy products are best consumed in a natural, fermented form (tempeh, miso, natto, etc.) and should always be organic. Unfermented soy products are rich in enzyme inhibitors that can diminish your body’s ability to digest carbohydrates and protein, and interfere with the absorption of zinc, calcium, iron and oral contraceptives. It also causes bacteria in the intestines, which can lead to gas! According to the Natural Health Bible, about 30% of the western population is allergic to soy, or finds that it does not agree with their digestive system. If you choose to eat soy, it is beneficial in moderate amounts (30 grams or less per day).

There’s a growing interest in stopping the use of conventional hormone replacement therapy because of its side effects. The soy foods industry has benefitted because of soy’s high phytoestrogen content. The lay press and soy industry have promoted the message that phytoestrogens act as surrogate estrogens, a conclusion not borne out in clinical studies. A recent study of menopausal women at the Mayo Clinic showed no benefit from soy protein isolates. A study at the Bowman Gray School of Medicine, in North Carolina, found a small reduction in the severity of menopause symptoms, but not their frequency.

A potential benefit of soy foods is the effect of soy protein on insulin and glucose levels. A 1997 study published in the journal Metabolism concluded that soy protein significantly improved cholesterol levels (in monkeys), which positively affected blood sugar levels and heart health.

Soy has also been studied to determine its effect on osteoporosis, which strikes westerners more than Asians. The question is whether or not this disparity is caused by differences in the amount of soy eaten. In fact, there is no evidence that soy foods protect the bones. Bone health can be attributed to an overall healthier lifestyle and diet. One way in which soy could improve bone health is as a replacement for animal fat, which creates an acidic environment in the body and draws calcium from the bones to neutralize this acidity.

While soy is beneficial in moderate amounts, it has the potential to do harm in higher doses. It is estimated that in Asian countries each person eats 30 grams of soy per day (about an ounce). This is enough to take advantage of soy’s cancer prevention effects, without causing potential problems. Avoid genistein or soy isoflavone pills and concentrates, and soybean oil, which has virtually no isoflavones and is usually hydrogenated. If you find that these foods do not agree with your digestive system, or you have headaches or other symptoms, you may want to avoid them as well.

Eating healthy is always a challenge, especially when there are benefits and risks to eating certain foods — plus an overload of various products and information. Try to keep current with available information, and base your decisions on what to consume (or not) on your own personal choices, health history and taste preferences. Most importantly, do everything in moderation!

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