Are Consumers Warming Up to Soy?

by Food and Drug Administration (FDA)

(Page 3 of 4)

Although it's clear that Americans are increasing their consumption of soy products, the soybean has a long way to go before it becomes a staple in the average pantry. According to a 1999 survey by the United Soybean Board, two-thirds of consumers surveyed believe soy products are "healthy," up from 59 percent in 1997. While the public may think it's good for them, only 15 percent eat a soy product once a week.

The reason for the disparity appears to be a problem of perception. "Americans are not prepared to make massive lifestyle changes in order to get healthy foods into their diet," says chef and soy cookbook author Dana Jacobi. "Many people have negative attitudes toward soy products due to their misconception of, or their experiences with, taste and texture. But in fact, there are so many ways to work soy into your diet."

Industry figures show that in some cases, the popularity of soy foods is increasing dramatically. For example, in 1998, sales of soymilk grew 53 percent in mainstream supermarkets and 24 percent in health food stores over the previous year, according to data from Spence Information Services, a San Francisco sales tracking firm. Another research firm, HealthFocus, reports that 10 percent of shoppers in 1998, versus 3 percent in 1996, said they are eating more soy specifically because they believe it will reduce their risk of disease.

According to the Soyfoods Association of North America, three factors are responsible for driving soy's upward trend:

Baby boomers are more enlightened about, and more interested in, longevity and good health than previous generations. The double-digit growth in Asian populations in the United States has fueled demand for traditional soy foods. Americans also are eating more Asian foods, which often include soy.

Young people are choosing more plant-based foods. A food industry survey found that 97 percent of colleges and universities now offer meatless entrées on their menus.

Mainstream grocery stores also have been prominently displaying soy products amid traditional foods. Soy-based burgers and sausages are often found in the freezer case next to other meats. Some stores offer refrigerated soymilk alongside cow's milk products. And it's not unusual to see tofu, along with soy cheese and cold cuts, in a store's fresh fruit and veggie department. "We expanded our line of soy products in the produce section even before [FDA approved] the health claim," says Paulette Thompson, nutritionist for Giant Food, a large East Coast grocery chain. "But soy is still rather mysterious to many consumers, so it's important to educate them." She says her company is offering information about soy in its Sunday newspaper supplements and its quarterly consumer magazine. It also plans a special "healthy products" promotion that will trumpet the benefits of soy and other diet components.

For consumers reluctant to try soy foods because they fear a bad taste, food manufacturers are creating new lines of soy-based products that contain enough soy to meet the claim requirement but are developed specifically to taste good. "Soy's major stumbling block has been its taste, real or perceived," says Meghan Parkhurst, spokeswoman for Kellogg Co. She says the company plans to introduce in several western states a granola-like soy cereal that got high marks for taste in consumer trials.

Examining the Controversy

While the existing scientific data strongly support the value of increasing soy protein as described in the health claim, questions have been raised about individual components of soy, especially when consumed as concentrated supplements by some segments of the population.

"FDA continues to monitor the debates about the relative safety of these individual soy components and the scientific research that will eventually resolve them," says the Center for Food Safety and Applied Nutrition's Lewis, "If new results suggest an increased risk, the agency will modify or refine its policies in light of the new information."

A number of studies already are under way or in the planning stages now. In one study, Barry Delclos, Ph.D., a researcher at FDA's National Center for Toxicological Research (NCTR), is overseeing a long-term, multigeneration study in rats of the soy component genistein. Early data using rats suggest that genistein alone may prompt undesirable effects such as the growth of breast tissue in males. The study will analyze the relationship between dosage and any adverse outcomes.

The National Institutes of Health is sponsoring a long-term follow-up study on the safety of soy infant formula. The study is a "longitudinal retrospective epidemiological" assessment in which young adults who consumed soy formula as infants will be compared with young adults who consumed milk-based formulas as infants. They will be evaluated for any adverse effects from infancy into their childbearing years.

NCTR's Sheehan says research is needed in this area because an earlier study, published in 1997 in the medical journal The Lancet, showed that infants consuming soy formula had five to 10 times higher levels of isoflavones in their blood serum than women receiving soy supplements who show menstrual cycle disturbances. He says these levels may cause toxicological effects. "Infants receive higher doses of soy and isoflavones than anybody because it is their only food and they are consuming it all the time." The American Academy of Pediatrics, however, has published guidelines showing that in some cases, soy protein-based formulas "are appropriate for use in infants" when cow's milk cannot be tolerated.

Sheehan also expresses concern about the effects soy may have on the function of the thyroid gland. Animal study results, some of which date back to 1959, link soy isoflavones to possible thyroid disorders, such as goiter. A 1997 study in Biochemical Pharmacology identified genistein and daidzein as inhibitors of thyroid peroxidase, which data suggest may prompt goiter and autoimmune disorders of the thyroid. Critics of these studies suggest that iodine deficiency may be a factor that needs to be considered when evaluating study results.

Though the research community has varying degrees of concern about a possible "dark side" to soy consumption, one thread runs consistently through its messages: the need for more research for new uses of soy components. The health claim, however, focuses on uses of soy protein that are generally accepted among health professionals as useful for heart-healthy diets.

Sales of soy foods probably will continue to rise steadily for the foreseeable future, says Sansoni of the Grocery Manufacturers of America. "We're seeing a 'buzz' with soy products that intrigues people and they want to try them," he says. "But I don't believe soy is a fad. It's a continuing trend that's here for the long haul."

With the rising interest, the health claim for soy protein appears to have succeeded. It has provided specific guidelines to help the public improve the heart-healthiness of its diet and has stimulated the industry to produce new food products high in soy protein. These trends, in the end, should be good for those trying to lower their risk of heart disease.

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.