(USA) The Downside of Soy - 20/20 Report - 6/9/2000

[Guest guest]

Tonight on 20/20 a special investigative report on

the upsides and downsides of soy.

 

Is a high soy diet for everyone.

Friday evening - on 20/20 - ABC-TV

http://abcnews.go.com/onair/2020/2020_000609_soy_feature.html

 

“We are doing a large uncontrolled and unmonitored experiment on human

infants.”

— Dr. Daniel Sheehan, research scientist for the Food and Drug

Administration and expert on soy.

 

By Brian Ross and Richard D. Allyn

 

June 9 — From tofu and tacos to burgers and baby formula, soy products have

swept the nation as a healthy source of high protein, with a reputation for

being all natural and all good.

 

But a 20/20 investigation has found that amid all of this praise, some

scientists are now challenging this popular wisdom, and suggesting there

may be a downside to this “miracle food.”

 

“The safety issues are largely unanswered,” says Daniel Doerge, a research

scientist for the Food and Drug Administration and an expert on soy.

 

New studies have raised questions over whether the natural ingredients in

soy might increase the risk of breast cancer in some women, affect brain

function in men and lead to hidden developmental abnormalities in infants.

 

This unresolved scientific debate continues to develop. Just last October,

soy enjoyed a huge boost when the FDA issued a health claim, concluding

that soy may lower both cholesterol levels and the risk of heart disease.

 

But two of the FDA’s experts on soy — Doerge and his colleague, Daniel

Sheehan — have stepped forward to criticize their own agency’s claim and

even attempted in vain to stop the recommendation. Their main concern: that

the claim could be misinterpreted as a much broader endorsement for soy

protein, beyond benefits solely for the heart.

 

Signing a highly unusual letter of protest to their employer, Doerge and

Sheehan pointed to research that demonstrates a link between soy and

fertility problems in certain animals. (You can find a copy of the letter in

the related stories section on the right-hand column.)

 

“The animal data is a clear indication for adverse effects, the potential

for adverse effects in humans,” Doerge says to 20/20.

 

Debate Over Soy Infant Formula

 

The core of their concern rests with the chemical make-up of soy: in

addition to all the nutrients and protein, exists a natural chemical that

mimics estrogen, the female hormone. Some studies in animals show that

this chemical can alter sexual development. And in fact, two glasses of soy

milk a day, over the course of a month, contains enough of the chemical to

change the timing of a woman’s menstrual cycle.

 

About 3 to 4 percent of babies must ingest soy formula because they are

allergic or can't digest regular milk formula. (ABCNEWS.com)

 

“We are doing a large uncontrolled and unmonitored experiment on human

infants,” Sheehan says. “We’re exposing infants to the chemicals in soy

infant formula that are known to have adverse effects in experimental

animals, and we have never looked in the human population to see if they

have adverse effects.”

 

The infant formula industry, along with some scientists, have blasted this

criticism of soy, calling it “scientifically unjustified claims that could

unduly frighten thousands of parents.”

 

Kenneth Setchell, a pediatrics professor at Children’s Hospital in

Cincinnati and a leading advocate of soy, contends that scientific studies

on soy show promise in fighting a number of diseases and that adverse

effects seen in animals do not apply to humans.

 

“There have been literally hundreds of thousands of infants that have been

raised on those soy formulas,” Setchell says to 20/20. “Some of those

infants would be well into their late 30s, early 40s now. And you know, I

don't see evidence of tremendous numbers of cases where there are

abnormalities.”

 

The debate over soy formula for infants poses a major issue throughout the

country. Soy infant formula is an undeniable lifesaver for the 3 to 4

percent of babies who are allergic to or can not digest cow’s milk.

However, heavy marketing of soy infant formula has led to its much wider

use, extending well beyond just those infants who are allergic to 25

percent of the entire formula market.

 

“My careful and considered professional opinion is that it makes more sense

not to needlessly expose your baby to these compounds,” says Dr. Claude

Hughes, director of the Women’s Health Center at Cedars-Sinai Medical

Center in Los Angeles. He adds that while breast-feeding is preferred,

mothers who don't breast-feed should use a milk-based formula and choose

soy as a last resort.

 

Other Health Concerns

 

Aside from his concerns about soy’s health effects on infants, Hughes has

also raised potentially more serious questions about soy and breast cancer.

In some cases, soy is thought to protect against breast cancer.

But some studies now indicate, for other women, the chemicals found in soy

may enhance a widely found kind of estrogen-feeding breast cancer.

 

“It can speed up divisions of those cells that are already cancer cells

that depend on estrogen for their growth,” Hughes tells 20/20.

 

The multibillion dollar soy industry has insisted that the health benefits

of soy significantly outweigh any potential risk.

 

Soy — consumed in the form of tofu — may have a connection to accelerated

aging in the brain, according to a three decade-long study begun by the

National Institutes of Health.

 

Dr. Lon White of NIH says that he found greater brain aging and shrinkage

among elderly men — all Japanese-American and living in Hawaii — who had

eaten tofu at least twice a week during middle age.

 

“Their brains, looking at them in terms of how their brain functions,

memory cognition, their brains seemed to be showing an exaggeration of the

usual patterns we see in aging,” White says.

 

The soy industry countered that White’s study only shows an association

between tofu consumption and brain aging, does not prove cause and effect

and is in conflict with research on Asian populations and animals.

 

While the scientific research on soy is still emerging and is often

contradictory, there are now some serious questions being raised about this

miracle food, and some of its staunchest defenders acknowledge that

these questions need to be answered.