Scientists are Rethinking Soy's Benefits-San Jose Mercury News
By Julie Sevrens
Imagine, Popeye beats out the evil Brutus and launches into a rousing rendition of his trademark song.
"I'm strong to the finish 'cuz I eats me soy..."
Doesn't rhyme, but it could have happened.
Had the pipe-toking sailor been a fixture of the year 2000, he most likely would have been singing the praises of soy along with just about everyone else. Hyped by manufacturers and dietitians alike, soy foods, we've been told, may reduce the risk of heart disease, prostate cancer and even osteoporosis. You can't get much stronger than that.
But just as Popeye wasn't real, now even some of the staunchest supporters of soy-based diets are beginning to question whether some of the plant's purported properties may be make-believe as well.
It's a controversial notion. Some would even say heresy. But if you listen to a growing number of scientists, you'll hear them suggest that the power of the soybean probably has been overstated in recent months.
"I think we're being duped. I truly do," says Dr. Lon White, a Honolulu researcher who recently shocked the nutrition industry with the results of his long-term, large-scale study of Japanese-American men living in Hawaii. The neuroepidemiologist, who says he never had placed much stock in the idea that nutrition influences health, found that consuming even small amounts of tofu--a derivative of soy--could contribute to a decline in mental abilities over time.
White's study, certainly not the last word on the potential drawbacks of soy, is starting to serve as a wake-up call to nutritionists as well as consumers, many of whom have long accepted that soybeans have positive medicinal qualities but somehow no side effects.
"Soy right now is back in one of those controversial corners," says Jo Ann Hattner, a Palo Alto nutritionist and spokeswoman for the American Dietetic Association. "It's because we don't know everything we should know probably" about soy's physiological effects.
Which is about the only thing most scientists studying the versatile soybean have agreed upon. Products or powder high in soybean protein have some pharmacological properties. But just how powerful, positive or predictable these effects can be is anyone's guess. "We are confused," says Sonia (Ghaemi) Gaemi, a Berkeley nutritionist who has been advising her clients to limit their consumption of soy.
Gaemi says she has seen more than a dozen men and women with health problems, which she attributes directly to excessive consumption of the legume. The reason they and so many other Americans, have embraced soy disturbs her.
"Women in general, they are thinking of it as fashion. 'If I am eating soy products, then I am in fashion,'" Gaemi says.
Not everyone may agree with her, but there's no mistaking that soy has become the dietary darling du jour, rising from once virtual obscurity to prominent positions on mainstream supermarket shelves.
The soy products market was a booming $2.1 billion dollar business in 1999, up from $1.4 billion just two years earlier, according to Nancy Chapman, executive director of the
Soy foods Association of North America.
Business is expected to get even better. The Food and Drug Administration agreed last October to allow manufacturers to promote their soy products as potentially capable of reducing the risk of heart disease. And in April, the U.S. Department of Agriculture began allowing school cafeterias to swap soy burgers and other soy products for meat.
Before such government support, more than one in four shoppers in the United States was already buying soy milk or soy foods, according to HealthFocus, a marketing research firm. Of the consumers polled by the organization, fully one in 10 mentioned trying to eat more soy because of the belief it would help reduce the risk of disease.
Their intentions weren't entirely misguided. Researchers say there is sufficient scientific evidence to believe that soy products do have some beneficial effects on health particularly in preventing heart disease and perhaps prostate cancer.
But neither the benefits nor drawbacks are as clear as researchers would like them to be. Much the research should still be regarded as speculative.
"I think that soy should at the very least be viewed like broccoli and other vegetables--as a food you want in your diet," says Mark Messina, associate professor of nutrition at Loma Linda University and author of "The Simple Soybean and Your Health."
But how much soy is too much? And what health improvements should consumers expect to see?
Messina says that is unclear. But he believes that people have already been expecting too much.
Moderation in meals is what many nutritionists are now encouraging.
"There's been an exaggeration of the benefits or what we know about the potential benefits," he says, pointing to many postmenopausal women who have been taking soy supplements in an effort to reduce hot flashes.
Scientists suspect that special components of the soybean, called isoflavones, are the active ingredient in the plant responsible for changes in the body.
Yet, "while isoflavones may have beneficial effects at some ages or circumstances, this cannot be assumed to be true at all ages," cautioned two members of the FDA while the agency was considering whether to allow soy manufacturers to tout their products as healthful. "Isoflavones are like other estrogens in that they are two-edged swords, conferring both benefits and risks."
That is something that Debra Myers, a Palo Alto stockbroker, says she knows herself all too well now. Months after giving birth to he daughter, Katarina, Myers found herself constantly exhausted but at the same time unable to sleep. At first, she attributed her fatigue and blurred vision to the new challenges of motherhood, but after months and months had gone by, it became apparent that something else was causing her problems, she says.
After seeing a nutritionist, Myers was told her diet was indeed to blame. Just 29 at the time, she had been eating soy at least three times per day, and her body had been difficulty digesting it.
But since her dietitian encouraged her to eat soy on a weekly rather than daily basis, her problems have all but disappeared.
Such moderation in meals is what many nutritionists are now encouraging.
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