By JUDY D’MELLO
Monday, August 19th, 2002

There isn’t a health-minded individual in America who is a stranger to soy. We’ve all heard about this near-perfect food’s miraculous benefits: It reverses osteoporosis, eases the symptoms of menopause, reduces the risk of heart disease, lowers cholesterol and even balances the mood swings associated with PMS. As beef turned into a four-letter word culminating in the mad cow scare, and dairy products were charged with creating allergies, soy became the protein of choice — the healthy alternative to red meat, chicken and milk. It’s no wonder food manufacturers and chefs all over the country figured out ways to turn the traditionally watery bean curd into delicious soy ice cream, yogurt,cheese, pasta, burgers and buns.

You may want to hold off before reaching for your next soy wiener, though.

“As little as a 5- to 8-ounce serving of soy milk a day has been proven to suppress thyroid function,” says soy researcher and nutritionist Michael Fitzpatrick. Drs. Daniel Sheehan and Daniel Doerge, former senior researchers at the Food and Drug Administration, have strongly opposed the soy industry’s proclamation that this humble bean is king. In a 1999 letter, the two scientists stated that rather than tout its health benefits, the FDA should attach a warning label to soy products. “The possibility that widely consumed soy products may cause harm in the human population via either or both estrogenic and [thyroid] activity is of concern,” said Sheehan in a recently published study.

Approximately 20 million Americans have some form of thyroid dysfunction — and women are 10 times more likely to suffer from an underactive thyroid (hypothyroidism) than men. The most common symptoms of a hypothyroid patient are lethargy, weight gain, depression, inability to tolerate cold, dry skin, coarse hair and mental “fogginess.”

The disorder usually occurs in women following childbirth and at the onset of menopause. By age 75, one in five women has a sluggish thyroid. Yet signs such as weight gain and lack of mental acuity are often chalked up to natural symptoms of the aging process.

The culprit in a high soy diet lies in the isoflavones found in the bean, in particular, genistein. Interestingly, this is the very same ingredient that’s been enthusiastically promoted as the remedy for everything from heart disease to mood swings. New research shows otherwise. “The isoflavones in soy act like a hormone in the body,” said Dr. Larrian Gillespie, a retired urologist and urogynecologist and author of “The Menopause Diet.” “In many women, especially those who eat large amounts of soy concentrates or take isoflavone supplements, this disturbs the body’s hormonal balance, triggering or worsening thyroid problems.”

Hundreds of new products

Gillespie speaks from firsthand experience. She first tried soy supplements at the recommended dose of 40 milligrams. “I went into full-blown hypothyroidism within 72 hours,” she said. Next she experimented with tofu. “Same results as before, but this time it took me five days to get there.”

Gillespie is troubled by the government’s recent announcement about the potential risks associated with hormone replacement therapy (HRT), which is followed by 6 million mostly menopausal women in the U.S. Drugs such as Prempro, Premarin and Climara were found to increase the rate of breast cancer and strokes. As a result, Gillespie is bracing for a “new push” for soy products by the industry that promise women a “more natural, risk-free” remedy for hot flashes and bone loss.

Soy is already a big business in the U.S. About 140 billion pounds of soy are produced annually here, making the U.S. one of the world’s largest producers and exporters of the bean. Hundreds of soy-based products are introduced each year. According to Sally Fallon, president of the Westin A. Price Foundation (http://www.westinaprice.org/), “Up to 1% of revenue for every soybean sold in America goes toward promoting the benefits of soybeans in the marketplace and maintaining and expanding foreign markets.” In short, the soy industry has clout.

Risk of thyroid cancer

A disturbing example of the industry’s heft is the marketing of soy-based infant formulas. While considered a life-saver for the roughly 3% to 4% of infants who are lactose-intolerant, this “healthy” alternative is so vigorously advertised that it claims a whopping 25% share of total infant formula sales. “It’s criminal that soy formulas are being sold in the marketplace,” says Fallon. “Infants who are exclusively fed soy formula get 10 times the dose of phytoestrogens found in a healthy Asian diet. Such excess can be harmful.”

Fallon also points out that the soy industry has known since the 1950s that soy formulas contain thyroid-suppressing agents. Though many have lobbied to have isoflavones removed from soy formulas, the high cost of doing so has prevented it from happening. For infants, any amount of soy is too much, according to the Soy Online Service (http://www.soyonlineservice.co.nz/). Unborn children exposed to high levels of antithyroid agents, the Web site says, are at high risk for prematurity and reproductive problems. Fitzpatrick, who heads the online service, also believes that long term feeding of soy formulas can raise the risk of thyroid cancer.

Following the money trail might show why more information is not available about these issues in the U.S. Experts believe the regulatory agencies are cowed by the strength of the agricultural companies that dominate the U.S. soy market. Other countries, where there is less economic pressure, have led the way in alerting the public to the potential hazards of soy. In 1996, the British Department of Health issued a warning that the phytoestrogens found in soy formulas could adversely affect infant health. In Switzerland, Australia and New Zealand, health officials recommend a medically monitored diet of soy products for infants and pregnant women.

A tub of tofu

Proponents of soy have long used the Asian diet as their war cry for pushing high intakes of soy isoflavones. “I went to China,” said Gillespie, “and saw how little soy is used in their daily diet. We in America think we must consume an entire tub of tofu in a meal, whereas in Asia a quarter tub [30 milligrams] is considered a lot for a day.”

Moreover, the Asian diet is dramatically different from its American counterpart, containing more fish, fresh fruits and vegetables, and less red meat, chemicals and processed foods. Soy is consumed not only in small quantities by Asians, but often in a fermented state such as tempeh (soybean cake), miso (a paste used in soups) and natto (sticky, boiled soybeans) that are high in Vitamin K. “Look,” says Gillespie, “if soy is the answer, then why is the typical image of an old Japanese woman shrunken and bent over?”

In the mid-’90s I fell hard for the hype surrounding the soybean. Believing the experts’ claims and looking for a low-fat protein, I became an avid consumer of tofu and a daily 12-ounce soy milk shake. I honestly liked the taste. Even after I was diagnosed with hypothroidism three years ago, I followed my “healthy” eating regimen. No one cautioned me of a possible correlation between my thyroid problem and soy consumption. I was 37 and suffered none of the classic symptoms.

Yet my thyroid stimulating hormone (TSH) levels clearly indicated an
underactive thyroid. It was only after my son was born, a year after my diagnosis, that I removed soy from my diet. (As an infant, he suffered from gastric distress, and since I was nursing, a friend suggested I go soy-free to eliminate the bean’s hard-to-digest properties from my system.) Six months later, I was checked again and my TSH levels were normal. Now, I eat only small amounts of soy, occasionally. I still get checked twice a year, and my levels are still normal.

How much is too much?

While deep-pocketed soy marketers cook up even more ways to ingest the bean, there is, unfortunately, little data as what constitutes an appropriate level of soy intake. Soy Online Service cautions that even 30 milligrams of soy isoflavones a day can wreak havoc on the body’s hormonal balance. It advises anyone with a predisposition to thyroid dysfunction to be particularly careful. If, indeed, the Asian diet is one to be emulated, then why not use soy the way they have for thousands of years: in moderation.

Thirty milligrams of soy isoflavones can be found in:

• 7 ounces of soybeans
• 4 ounces of tofu
• 8 ounces of soy milk
• 1.6 ounces of miso
• 2.8 ounces of soybean sprouts