Soy isoflavones
Soy isoflavones
What is it? Soybeans are legumes that are considered a complete protein and provide us with ALA omega-3s, iron and calcium. They also provide phytoestrogens (isoflavones are one type of phytoestrogen), which produce estrogen-like effects on the body and are thought to help prevent or treat diseases.
Where is it found? Obviously the most direct source of soy is the soybean. However, given that neither soybeans nor tofu has an overwhelming number of fans, most of us get soy from such products as soymilk, meat substitutes or soy-enriched cereals.
The claim: Since researchers in the U.S. halted the Women’s Health Initiative study on hormone therapy (HT) in 2002 after finding long-term use increased the risk of heart disease and breast cancer, there has been renewed interest in soy, particularly isoflavones. Articles have reported that soy reduces “bad” cholesterol, prevents osteoporosis, eases menopausal symptoms, and even prevents certain cancers. But can 10 mg of soy isoflavones in a 1/2 cup of Nature’s Path Organic Soy Granola cereal make a difference in our health? Lambert-Lagacé thinks not. “A 10 mg serving doesn’t mean much if you’re in midlife and have hot flashes,” she says. “You want 75 to 100 mg of isoflavones [a day] to reduce them.”
Studies have found that the more “real” and less processed the soy foods — like edamame (whole soybeans) and tofu — are, the richer the isoflavone content, offering greater health benefits than those from isolated isoflavones found in supplements and such foods as enriched cereals. “In terms of heart health and lowering cholesterol, we don’t really know which components are helpful,” says McConkey. “Is it the isoflavones or the fibre in soy? I think it’s better to go with whole soy than something with isoflavones added to it.”
The scientific literature is confusing. While some studies show positive benefits of soy isoflavones on hot flashes, heart disease, breast cancer and increased bone mass, others say the evidence is inclusive or flawed. Experts are of two minds when it comes to breast cancer and soy consumption, because of soy’s phytoestrogen component. “Some experts are cautious about women with estrogen-positive receptor breast cancer having soy,” says McConkey. “Others feel three to five servings of soy a week is safe.” The American Cancer Society has suggested to breast cancer survivors to use soy supplements in moderation, and Lambert-Lagacé believes it’s fine to eat whole soy in moderation. “Soy isn’t considered a preventive measure for breast cancer in midlife women, but it won’t trigger the disease.”
Osteoporosis is another area where studies conflict. This may be remedied by a two-year, randomized, double-blind U.S. study that looked at 400 post-menopausal women taking different dosages of soy isoflavone supplements or a placebo. Results aren’t in yet — data analysis began in November 2006 — though preliminary findings look positive.
The bottom line: Lambert-Lagacé believes whole, less processed foods are the ones that give the true health value. “If there’s a choice, opt for the real stuff.” But Holub sees a bright future for functional food components as a low-cost, preventive healthcare model. “I can see walking into a grocery store where a life science grad pricks your finger, gets a cholesterol level and then tells you the cholesterol-lowering foods are in Aisle C.”
This article originally appeared in the September 2007 issue of More
