DEAR DR. BLONZ: I have an interest in "real food" supplements, specifically soy supplements, and would appreciate your opinion. You recently wrote about soy and thyroid hormones, but I am interested in soy isoflavones to help with the symptoms of menopause. I don't have much soy in my diet, and wanted to know if taking a supplement would be a good strategy. -- P.L., Chicago
DEAR P.L.: The idea of a "real food" supplement is a bit of a contradiction in terms: Nothing compares with real food. Science has only begun to identify the healthful elements in the foods we eat. Each new study can provide greater awareness about a specific component, and if the research sounds promising, it can breed interest in spinoff products in pill form.
But all this misses the "whole food" point. It is unlikely that a single element holds the key. The smart money rests with the concept that all of a food's elements working together -- that is, the whole food itself -- provides the magic. This makes perfect sense, as whole foods represent an interactive, nature-evolved system designed to survive. What's more, these systems have passed the test of time -- a critical asset when considering GMO crops, as they sidestep this process.
Now, on to the specifics of the soy isoflavones. The isoflavones are phytochemicals (phyto = plant) unique to soybeans. They have a number of abilities and are antioxidants, which may have a direct role in soy's beneficial effects.
Isoflavones have structural similarities to estrogen, but eating soy isn't like taking estrogen. The isoflavones don't function as estrogen in the human body. They only have a "weak estrogenic effect" -- only one-hundred-thousandth (1:100,000) as potent as estrogen. The build of the isoflavone is believed to play a role in some of soy's observed beneficial effects, as it may bind with the body's natural estrogen receptors in a way that lessens estrogen's negative effects. Higher levels of (human) estrogen, for example, are connected with an increased risk of certain hormone-related cancers, such as breast cancer. Studies have shown how populations eating soy-based diets have a lower incidence of breast cancer. Diets containing soy may also protect against colorectal cancer in women: A study in the February 2009 issue of the American Journal of Clinical Nutrition reported that for every 5 grams per day of soy food eaten, the risk decreased by 8 percent.
This is one reason health professionals have encouraged people to have more soy in their diets. For someone who wants soy's benefits, but is not able to have soy in her daily diet, your soy extract capsule may actually seem like a good alternative. I would tend to agree -- but with reservations.
First is the fact that soy foods offer much more than isoflavones. Soybeans contain protein, vitamins, minerals, fiber and essential fatty acids, in addition to other valuable phytochemicals. (Check the information sheet from University of California at Davis at goo.gl/0YcpKv.) If you only take the isoflavones, you miss out on other components that are likely to play a role in soy's whole-food beneficial effects.
Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to email@example.com. Due to the volume of mail, personal replies cannot be provided.