The Joy of Soy
Laura Lippman points to a quart of soy milk on her desk.
It’s one of a dozen products she has assembled to demonstrate the new food choices for those wishing to increase their soy intake. Soy milk is ideal for the totally natural, “no additives, please” consumer, says Lippman, vice president of sales for Stonecrest Natural Foods in Inglewood, a soy products manufacturer.
There is a “handful” of those hard-core soy consumers, she says.
Then there are the rest of us, who got interested in soy only recently, after a spate of studies suggested that the simple little soybean--packed with protein and hormone-like substances called isoflavones--can reduce cholesterol, build bone mass, alleviate the hot flashes associated with menopause, and possibly reduce the risk of prostate and breast cancers.
In this camp of recent converts reside a number of folks who think chocolate-covered soy sounds much tastier than tofu (especially when tofu is called by its nasty alias, soybean curd).
Fortunately, as researchers have been busily studying the health benefits of soy, manufacturers have been working overtime too. So now it’s possible to find something soy-based for almost any meal, or in between, at grocery or specialty stores, health-food stores or by mail order.
Among the options: soy wieners, cheeses, powders, flour, pills and, yes, even a chocolate-coated soy bar. There are also soy performance-enhancing drinks and soy protein shakes. Miso, a fermented soybean paste, can be used as a soup base. Tempeh--soybeans combined with grains--can be used as a meat substitute. Tofu now comes dressed up in spicy and barbecue flavors or with added parsley and oregano, ready to add to soups or other dishes. Among products expected on store shelves soon are soy protein soups and oatmeal with soy.
Fresh soybeans, which usually come two beans to a pod, are difficult to find. But specialty markets often carry frozen edamame, a soy bean snack. “They’re addicting, like peanuts,” Lippman says.
Someone’s taking the soy message seriously. U.S. sales of soy products are booming--topping more than $1.1 billion in 1996, compared to $300 million in 1980, according to the Soyfoods Assn. of North America, a trade group.
Researchers still don’t completely understand how soy protein or its two isoflavones, called genistein and daidzein, yield health benefits.
“Isoflavones act like natural estrogens, but the potency of the estrogen effect is not as great,” says Dilprit Bagga, a UCLA nutritionist and research scientist at UCLA’s Jonsson Comprehensive Cancer Center. She is involved in a study to determine if boosting soy intake might delay the recurrence of breast cancer. The isoflavones bind to receptors for estrogen and testosterone, blocking the effects of the hormones, she says.
When it comes to cholesterol reduction and bone building, it’s thought that soy protein and the isoflavones somehow work together. “The relationship between the isoflavones and the protein is complex,” says Dr. James Anderson, professor of medicine and clinical nutrition at the Veterans Affairs Medical Center in Lexington, Ky., and a longtime soy researcher.
At an American Heart Assn. meeting last month, Dr. John R. Crouse III and his colleagues from the Wake Forest University School of Medicine in Winston-Salem, N.C., presented the results of their study of 156 subjects with moderately high cholesterol who took soy protein with differing amounts of isoflavones, ranging from just a trace to 58 milligrams of isoflavones a day. Reductions in total and so-called bad cholesterol were seen with the soy and high isoflavone diet, but not with the diet containing just traces of isoflavones.
The isoflavones might be the real workhorses in reducing the risk of breast and prostate cancers and easing menopausal hot flashes, researchers say, and are not easily part of many people’s diets.
“Soy foods are unique sources of the important isoflavones genistein and daidzein,” Anderson says. “There may be small amounts of these isoflavones in black beans, but this has not been as well studied and is less definite.”
For those who include soy in the diet, “I recommend seven servings a week,” says Anderson, defining a serving as eight to 10 grams of soy protein per serving.
UCLA’s Bagga recommends a somewhat lower intake, two or three servings of soy foods a week for general health improvement. She cautions consumers not to go overboard on soy. She believes the 60 grams a day of soy she is giving to subjects in her study of breast cancer recurrence should be the upper limit.
The easiest way to boost soy intake is to sprinkle isolated soy protein powder into orange juice and other beverages. Consumers should check labels. Most isolated soy protein products are processed with water, Anderson says, leaving more isoflavones in the finished product. Soy products that have been processed with alcohol, which is used to diminish the soy smell and taste, have a much lower concentration of isoflavones.
“Start to think of soy as yet another healthy food to add to your diet,” says Mark Messina, an adjunct professor of nutrition at Loma Linda University and soy researcher in Port Townsend, Wash., who sometimes works as a consultant for the soy industry. “When you have cereal, reach for soy milk,” he says. “Use tofu when making chocolate mousse pie. I think that would break the psychological barrier against tofu.”
When picking a soy product, be sure soy protein is the first or second ingredient listed on the label, Messina says, to ensure you are getting adequate amounts. (And be aware that soy sauce and soybean oil have almost no isoflavones.)
Popping a few soy pills might seem like the easiest solution, but Anderson cautions consumers to avoid them. Soy pills sold in health-food stores often contain only the isoflavones, so you could miss out on the important benefits imparted by the soy protein. And isoflavones in pill form have not been studied, Anderson says.