Dear Earth Talk: How healthy is soy? I heard that, despite its healthy image, most soy is grown using chemicals like other crops and is even being genetically modified.--D. Frinka, Syracuse, NY
Food products made with soy have enjoyed great popularity in the U.S. and elsewhere in recent years. Two decades ago, Americans spent $300 million a year on soy food products; today we spend over $4 billion. More and more adults are substituting soy--a great source of protein--for meat, while a quarter of all baby formula contains soy instead of milk. Many school lunch programs nationwide have added soybased veggie burgers to their menus, as have countless restaurants, including diners and fast food chains.
And there are hundreds of other edible uses of the legume, which now vies with corn for the title of America's most popular agricultural crop. The U.S. Food and Drug Administration promotes the inclusion of soy into other foods to cut down on heart attack risk. Clinical studies have shown that soy can also lower the risk for certain types of breast and prostate cancer.
But there may be a dark side to soy's popularity and abundance. "Many of soy's health benefits have been linked to isoflavones--plant compounds that mimic estrogen," reports Lindsey Konkel in Environmental Health News. "But animal studies suggest that eating large amounts of those estrogenic compounds might reduce fertility in women, trigger premature puberty and disrupt development of fetuses and children." But before you dump out all your soy foods, note that the operative phrase here is "large amounts" which, in laboratory science, can mean amounts substantially above what one would consume in real life.
Also at issue is that upwards of 90 percent of the U.S. soybean crop is grown using genetically...