This versatile vegetarian protein source comes in the form of burgers, chips and milk — but as prevalent as it is, many people are unclear if soy is good for them or potentially harmful to their health.
After researchers cautioned against consumption of soy protein, reporting findings that soy increased the risk of breast cancer, many people became wary of this previously highly touted health food. Despite these findings, the U.S Food and Drug Administration authorized a health claim for products containing at least 6.25 grams of soy protein per serving stating that soy, “as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease.”
It’s understandable that this contradictory advice would leave any consumer confused and ambiguous regarding soy’s status as a “health food,” or something quite opposite.
When it comes to the research regarding soy’s role in promoting breast cancer, results must be taken with a grain of salt. The research showing possible harmful effects of soy products were based on studies isolating a specific component of the soy plant, called isoflavones — namely a specific type of isoflavone found in soy called genistein. Isoflavones such as genistein act as phytoestrogens, a weak type of estrogen that activates estrogen receptors in cells, including breast and tumor cells. These isolated isoflavones are sold in a concentrated pill form marketed to menopausal women as a remedy to help relieve symptoms such as hot flashes. In postmenopausal women, high levels of isoflavones such as genistein have been linked to a higher risk of breast cancer.
It makes sense that just as a couple of components of the soybean were isolated when conducting these studies, they are not telling us the whole story. When consuming a whole, intact soybean, there are many biologically active ingredients that work together to have multiple effects on the body.
Researches think that when a soybean is consumed in its whole form, the different compounds can interact in ways that reduce the negative outcomes that one individual component, such as genistein, may have. For this reason, the FDA limited its health claim advertising soy’s heart healthy benefits to intact soy protein, not one or two isolated constituents.
The National Cancer Institute and the American Cancer Society recommend that breast cancer survivors can safely consume moderate amounts of soy foods — anywhere from a few servings a week to three servings a day. Research has even shown that intake of soy foods may be protective against breast cancer, especially if consumed during childhood and adolescence.
Press reports cautioning against soy’s consumption should not cloud our vision of this legume’s various health benefits. Soy contains many antioxidants that can help prevent chronic diseases associated with oxidative stress such as cancer, cardiovascular disease and diabetes. Soy protein is also a highly digestible, high-quality form of protein comparable to beef, milk, fish and egg protein.
Its ability to support increased muscle mass while at the same time being low in cholesterol and saturated fat make it a great substitute for meat sources of protein when considering heart health. Additionally, studies have found that soy reduces blood cholesterol levels about 3 percent to 5 percent, which is why the FDA recognizes that 25 grams of soy each day (four 6.25 grams servings) may reduce the risk of heart disease. Further studies support that the cholesterol-lowering effect of soy protein may be increased to as high as a 13 percent to 14 percent reduction when combined with other foods such as plant sterols, viscous fibers and nuts.
After looking at the facts, we can put to rest the ambiguity surrounding soy’s status as a healthy versus unhealthy food and safely say that it is a great vegetarian source of protein that can be included as part of a healthy, balanced diet.