Fab bean or has-been?

WHEN soy burst onto the Western food scene in the early 1990s, the possibilities for the bean seemed boundless. The protein-packed legume had potential to prevent breast cancer, increase bone mass, alleviate hot flashes. It seemed to lower cholesterol, and thus to help prevent heart disease.

Millions of dollars were poured into research, and technologists plopped soy into every food imaginable. They ground it into burgers, hot dogs and sausages (Tofurky was born). They processed it into cheese, milk and ice cream. Manufacturers added it to baby formula, and baristas foamed it into lattes.

Purists consumed soy in its traditional Asian forms -- as tofu, tempeh or edamame -- while hard-core health nuts sought out soy protein powder or isoflavone-packed supplements.

But 15 years later, with ever more soy products available in the grocery store and conspicuous soy consumption a cultural shorthand for “Hey, I’m health-conscious!”, the tides are turning against the Asian wonder food.

Call it the “soy backlash.”

A crop of books and articles are now warning about the dangers, not benefits, of the bean.

Soy now has its very own tell-all, penned by a certified nutritionist: “The Whole Soy Story: The Dark Side of America’s Favorite Health Food.”

It’s being tracked by an international watchdog group, the Soy Online Service, whose mission is to “uncover the truth about soy” and inform consumers about “the plethora of criminal and dangerous lies that issue from the soy industry.”

Soy, we are warned, can do terrible things should we overdose on tofu or soysauge, suggests the men’s magazine, Best Life: “Grow man boobs! Shed muscle tone! Boost estrogen! Saps your sex drive!”

These reactions are extremes. But even mainstream scientists are pulling back on once-heady health predictions for the bean. New research is showing that soy is not the magic bullet researchers once hoped it might be.

Yet these scientists also see soy’s fall from grace as the latest casualty in Americans’ endless -- and unrealistic -- search for a single substance that can change your life.

“It’s just food!” says soy guru Mark Messina, an adjunct professor of nutrition at Loma Linda University in California, who has written books on its health effects and consults for the soy industry. “We are talking about diet here. Not the fountain of youth.”

The vegetable in the hairy pod is a pretty complicated bean. Native to China and Japan, it is termed the “king of legumes” because it has the most complete protein of any member of the pea family. It is high in calcium, magnesium and vitamin B, and contains estrogen-like chemicals -- isoflavones.

Soy has had its share of celebrity champions. Henry Ford was batty for the bean. He created a car made out of plastic from soybeans, wore a soybean suit and soy fiber tie at various public functions, and served a 15-item soy menu at the 1934 World’s Fair.

But it was in the 1990s that evidence of soy’s possible benefits began to mount (see sidebar) and books and magazines took the science and ran with it. “Are soy isoflavones the women’s health powerhouse?” asked a 1997 article in the newsletter the Nutrition Reporter, adding that soybeans might end up “the ultimate women’s health supplement of the 21st century.”

The market for soy foods exploded.

Over the last 10 years, the average growth rate of soy products has been about 14% a year, says Peter Golbitz, president of Soyatech, a soy industry information company. Even now, he says, soy sales continue to grow, albeit less briskly. “We have been selling to baby boomers and hippies for the past 20 years,” he says. “Now it is time to embrace the changing demographic of the American consumer.”

That, he said, includes Latinos, Gen X-ers and Y-ers.

Perhaps no food could withstand the hype heaped on soy. But with more rigorous scientific examination, the bean’s starry promise seems to be crumbling.

In January, the American Heart Assn. published an advisory pulling back on its earlier, 2000 stance on soy, which had recommended “including soy protein foods in a diet low in saturated fat and cholesterol.” January’s statement said that a review of 22 studies showed that soy protein with isoflavones did not, after all, seem to improve cholesterol. Thus, the association said, it “could not recommend the use of isoflavone supplements in pills or food for the prevention of heart disease.”

Alice Lichtenstein, a nutrition scientist at Tufts University and the chair of the heart association’s nutrition committee, says the scientific cart simply got ahead of the horse.

“Soy is good,” she says. “Soy as a food is very good” -- but only because it has healthier fats and vitamins than, say, meat. If you eat a soy burger, you are not eating a hamburger. If you are eating a tofu pup, you are not eating a hot dog.

This April, there was more bad news for soy. Although many women consume soy or soy supplements in the hope of preventing breast cancer, a study in the Journal of the National Cancer Institute found differently.

After analyzing 18 studies, the authors concluded that eating soy may very slightly reduce the risk of breast cancer -- but not enough to recommend soy foods or supplements.

For breast cancer survivors, taking soy supplements (as opposed to food) could actually be ill-advised, says study coauthor Robert Clarke, a professor at Georgetown University’s Lombardi Comprehensive Cancer Center.

Unlike soy foods, supplements contain high levels of estrogen-like isoflavones, such as one called genistein. And estrogens coax breast tumor cells to divide, says coauthor Leena Hilakivi-Clarke, a professor of oncology at Georgetown.

The hot flash connection has also begun to erode. In early trials, soy isoflavones reduced hot flashes by 9% to 40% in menopausal women, but most of the 25 or so trials done later showed no difference from placebos.

More than soy’s effectiveness is now under scrutiny: A few scientists are actually voicing fears about its safety.

Some worry that soy may affect thyroid function, and even interfere with the absorption of synthetic thyroid hormones. (However, a March review of 14 trials found that neither soy protein nor isoflavones adversely affect the gland.)

Others are worried about reproductive problems. Last year, researchers at the National Institute of Environmental Health Sciences found that mice given genistein right after birth developed irregular menstrual cycles and problems with ovulation and fertility. This year, they reported that genistein disrupted the development of ovaries.

“Whether these things cause problems in humans, we just don’t know,” says Wendy Jefferson, an NIEHS scientist and the paper’s lead researcher. “But so many babies are on soy formulas. If these things are going to be a problem ... it is a problem that would only manifest later, when a woman was trying to get pregnant, or having reproductive cycle problems.”

The research led an independent panel of 14 scientists to meet in March and decide whether soy formula -- fed to an estimated 10% to 20% of U.S. infants -- is hazardous to human development or reproduction.

The panel concluded that soy formula was safe but the one pediatrician on the panel expressed concerns. Dr. Ruth Etzel, who works at the Alaska Native Medical Center in Anchorage, says exposure to soy formula occurs during a critical time in infancy and might possibly affect development of the brain and reproductive system.

Yet even as some soy fears grow and much of its promise is being shot down, new possibilities are popping up.

A recent study suggested that if women consume soy during the third trimester of pregnancy, it could help program fetuses with a craving for healthful foods and a good metabolism.

Others suggest that when women eat soy could be key. Research by Anna Wu, professor of preventive medicine at USC, suggests that girls who eat a lot of soy during adolescence -- when their breasts are developing -- may be less likely to get breast cancer later.

And bone strength may be one place where soy really delivers. A three-year, $3.4-million study funded by the National Institutes of Health is testing whether soy isoflavone supplements can help preserve bone in the lower part of the lumbar spine in post-menopausal women.

Nutritionists watch the very public taking down of soy with bemusement -- and slight exasperation. Many point out that meta-analyses (which pool results of different studies together) are not the best way to determine a food or medicine’s effectiveness -- especially in the case of soy because the product comes in so many forms.

But they also see the fall of soy as part of the cycle of American pop culture, be it celebrity or bean: hoist it up to impossible heights, then drag it down and bash it. The truth about soy, they say, is somewhere in the middle.

“Soy is eaten by two-thirds of the world’s population.” says Dr. David Heber, director of the UCLA Center for Human Nutrition -- apparently quite safely. If anything is problematic, nutritionists say, it is the quintessentially American habit of assuming that if a little of something is good, then a lot must be really good. Eat soy as a food, they add. It would be nearly impossible to overdose from eating too much tofu, tempeh or soy burger.

And be realistic.

“If a drug company came up and said ‘We are going to develop a product that reduces the risk of heart disease, reduces the rate of prostate cancer, that alleviates hot flashes and does good things for bone, and that doesn’t have any side effects,’ they would be laughed out of the room,” says Dr. Gregory Burke, a professor in the department of Health Sciences at the Wake Forest University School of Medicine.

But just because soy is not a magic cure for hot flashes and breast cancer does not mean it isn’t a good food.

“It should be thought of in the same way that people think of exercising, not smoking and a prudent diet,” Burke says. “It is not to be overdone, and not to be said it is worthless.”

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Soy’s medical side

The idea that soy could help with chronic diseases, especially women’s diseases, came from comparisons of Asia to the West. Rates of breast cancer, heart disease and endometrial cancer were known to be much lower in countries such as Japan, where soy foods like tofu are frequently eaten.

It is hard to boil vast cultural differences down to a few foods, but scientists tried to adjust for other lifestyle differences and found that after they’d done that, eating soy still appeared protective.

The data were intriguing enough that in 1991 the National Cancer Institute made millions of dollars available for soy research.

In 1995, the New England Journal of Medicine published an analysis of 38 clinical trials that found eating an average of 47 grams of soy daily reduced bad (LDL) cholesterol by 12.9% -- the same effect as modernday statins, and with no apparent side effects.

“To find a food that lowered cholesterol 13% was phenomenal,” says soy scientist Mark Messina.

In 1999, the Food and Drug Administration granted a health claim for soy: Foods with 6.25 grams of soy protein a serving (and which were also low in fat, cholesterol and sodium) could bear a label declaring that the protein might lower heart disease risk.

Right around that time, women’s health was gaining attention and boomers were hitting menopause. Hot flashes became the topic du jour. Soy, again, took center stage.

Scientists hypothesized that soy’s so-called phytoestrogens might be why Japanese women’s rate of hot flashes is one-third that of Americans. Early research supported that notion.

Studies have also shown that Asians who eat soy have higher bone density than Asians who don’t; animal studies suggest that both soy and soy isoflavones can keep bones dense.

Small, clinical trials are encouraging: A study published in the American Journal of Clinical Nutrition in 2000 reported that perimenopausal women who took 80 milligrams of soy protein powder with isoflavones daily over six months did not lose any bone mass in their lumbar spine region.

A control group who took whey protein lost a small but significant amount of bone (1.3%).

-- Hilary E. MacGregor