Eat Your Soy, Boy
By Sally Squires
Washington Post Staff Writer
Tuesday, May 4, 2004; Page HE01
Yes, it's true that your wife, girlfriend or significant other has been eating
a lot of soy lately, mainly to boost her female hormones. That doesn't mean
it's bad for you, fella. Instead of pushing aside that soy milk, go ahead
and pour some on your morning cereal. Dig into the soy burgers at the office
cafeteria and the tofu that appears in your takeout stir-fry.
It turns out that soy, at least in the doses most people will consume it
in food, may be good for guys, too. A growing number of studies suggest that
soy has plenty of health benefits for men -- from lowering cholesterol levels
to protecting against prostate cancer -- and few downsides.
"Real men should eat soy," said Kenneth Setchell, professor of pediatrics
at the Cincinnati Children's Medical Center, who has studied soy for 30 years.
"Generally, men are put off by soy. It tends to be sort of a woman's thing.
That's a great pity, because the evidence that soy protects against prostate
cancer is quite strong."
While there have been worries that men who consume large quantities of low-carb
soy bread, soy cereal or other soy-filled foods may get a little too in touch
with their feminine sides, research findings have generally not borne out
"Soy is a very healthy food," said physician James Anderson, who has studied
soy for 15 years at the University of Kentucky in Lexington and is convinced
enough of its benefits to eat about a dozen servings of soy per week. "It's
Most concerns about soy have centered around the fact that it is a rich source
of isoflavones, substances that mimic the effects of the female hormone estrogen.
To determine what these plant-based chemicals might do, Steven Zeisel and
his colleagues at the University of North Carolina at Chapel Hill fed megadoses
of soy to men as part of a recent National Cancer Institute study.
Nipple discharge, breast enlargement and slight decreases in testosterone
occurred with the megadoses. But "we still couldn't find anything that was
serious, and we went up to doses that are probably 30 times what you could
get from normal foods," Zeisel said. "I don't think that there are a lot
of estrogenic worries. Your testicles will not shrink and you won't have
massive breast enlargement" from eating soy.
And if you stick with foods rich in soy as opposed to supplements, researchers
say, there's no evidence of harm, unless you happen to be among the one in
every 1,000 people who are allergic to soy. "It's quite difficult to overconsume
soy, to be honest," said Setchell.
Not only is soy a rich source of high-quality protein, but it also contains
complex carbohydrates that don't raise blood sugar as high as more processed
carbohydrates. It has fiber, folic acid (a key B vitamin), healthy fat and
antioxidants that help protect against cancer.
There's also evidence that soy acts as a probiotic in some people, promoting
growth of healthy bacteria in the gastrointestinal tract that in turn produce
health-promoting substances. While it's possible these days to eat soy at
every meal and snack, it only takes a small amount of soy to produce health
benefits. Less than a handful of soy nuts, about a fifth of a cup, provides
12 grams of protein, said Anderson, who keeps a stash near his desk for snacks.
"If you can eat a third of a cup a day, that would give good protective levels
in terms of heart disease."
Will such soy-filled products as low-carb bread, soy cereal, soy crackers
and cookies have the same benefits as traditional soy sources?
"My feeling is that soy milk and tofu have the best test of time," said David
Jenkins, professor and chairman of nutrition and metabolism at the University
of Toronto and St. Michael's Hospital in Toronto. The soy isolates found
in meatless burgers and hot dogs "have also been shown to be very effective,"
Jenkins said. By contrast, soy sauce has only minimal levels of active soy
ingredients and comes with massive amounts of sodium.
Just resist any urge to eat raw soy. Uncooked soybeans contain a substance
that inhibits trypsin, a key enzyme required for protein digestion. "Horses
who eat raw soybeans die," said Zeisel. While raw soybeans may not be as
deadly for humans as they are for horses, Zeisel said it's not worth the
risk: "Don't ever eat soybeans raw."
Here's how cooked soy stacks up in health benefits:
Bone health Studies suggest that soy helps preserve bone and may help build
it in some people. While nearly all the research has been done in women,
who suffer more extreme bone loss with age than do men, researchers say there's
no reason to suggest that soy may not also help protect older men from osteoporosis.
Blood pressure Soy appears to lower blood pressure slightly. It also seems
to lower blood pressure by "improving elasticity of blood vessels," Setchell
Cholesterol Since 1999, foods containing 6.25 grams of soy protein per serving
can be promoted for their ability to lower blood cholesterol when combined
with a diet low in saturated fat and cholesterol. About 25 grams of soy protein
daily helps lower the most damaging form of blood cholesterol -- low-density
lipoprotein (LDL) -- by up to about10 percent and total cholesterol by up
to 7 percent, according to Anderson. There's also evidence that blood triglyceride
levels rise less after a meal containing soy and that eating a diet rich
in soy may help reduce the metabolic syndrome -- a constellation of symptoms
that include elevated cholesterol, blood pressure and extra fat at the waistline.
Colon cancer A few studies suggest that soy may help protect against colon
cancer, but the evidence is still emerging.
Diabetes Soy contains healthy carbohydrates with a low glycemic index, meaning
they are less likely than more-processed carbs to raise blood sugar levels.
New research also suggests that eating soy food appears to help protect the
kidneys of those with diabetes, especially those with type 1.
Studies in Europe and at the University of Illinois also suggest that soy
helps reduce protein in the urine of people with diabetes, which can help
reduce kidney damage, a common complication of diabetes.
Hair loss Soy helps boost production in the intestines of equol, a substance
that binds to dihydrotestosterone, the chief culprit in causing hair follicles
to die. Although still in early investigation, Setchell and other researchers
theorize that boosting equol could help protect against baldness.
Muscles As a protein source, soy ranks at the top of the list. But no need
to take massive doses of soy protein supplements or powder to build more
muscle. Eating a soy burger, a handful of soy nuts or a soy smoothie after
a weight training session is plenty to help repair muscle, according to Jeff
Potteiger, an exercise physiologist at Miami University in Ohio.
Prostate In Asian countries, where soy consumption is high, incidence of
prostate cancer is similar to that in Western countries, but the disease
is much less likely to kill. Studies of Seventh-Day Adventists, who eat no
meat, have found that drinking one glass per day of soy milk appears to lower
prostate cancer risk by 30 percent; two glasses per day may lower risk by
up to 70 percent. At the University of North Carolina, researchers found
men with elevated blood levels of prostate-specific antigens (PSA) who took
megadoses of soy showed a significant slowing in rise of the PSA.
Waistline Soy foods are lower in calories, total fat and saturated fat than
comparable meat products, and they have zero cholesterol -- all benefits
that can help protect against obesity. There's also some evidence that soy
may help reduce buildup of dangerous visceral abdominal body fat, according
For that reason, some soy researchers, including Anderson, Setchell, Jenkins
and Zeisel, say they're putting their findings into practice by pouring soy
milk on their cereal, snacking on soy bars and eating a soyburger instead
of a hamburger. Example: A beef burger has about 190 calories, 11 grams of
fat, four grams of saturated fat, zero carbs and no fiber, while a soyburger
contains 50 fewer calories, a third of the fat, 10 grams of carbohydrates,
three grams of fiber and zero saturated fat and cholesterol.