Natural Foods Merchandiser: Can eating too much soy be bad for my health?
Store (Independent natural foods store on the West Coast): As long as you stick to minimally processed sources, like soybeans and tofu, I think it’s fine to eat soy regularly.
NFM: What about phytoestrogens and genetically modified organisms?
Store: In Asia, they’ve been eating soy for thousands of years, and those people are some of the healthiest in the world. I would avoid eating a lot of processed foods with soy isolates, though. You’re right to worry about GMOs, but we have several organic soyfoods. Would you like me to show you?
How did this retailer do?
Our expert educator: Andrew Weil, MD, founder and director of the Arizona Center for Integrative Medicine
Despite a long history of use as a food and numerous scientific studies, eating soy remains controversial. Some research has linked high soyfood intake to an increased risk of certain illnesses, while other studies have shown its protective effects. Part of the disparity may have to do with the form of soy a person regularly eats.
The retailer is right in that most of the studies with positive results, including lower rates of breast and prostate cancers, have come out of Asian countries where soy is primarily consumed in the form of whole, unprocessed foods such as tofu, tempeh, soymilk, soy nuts and edamame. The phytonutrients present in whole soyfoods may help lower cholesterol, tame hot flashes in menopausal women and help protect against osteoporosis, heart disease and certain cancers. I remain convinced that one or two servings a day of whole soyfoods is both safe and nutritious.
Because soy crops are often heavily sprayed with pesticides and other agricultural chemicals, the retailer is correct to recommend organic, whole soy products. Buying organic also ensures that you’re not eating genetically modified soybeans. One study found that GMO soybeans appear to have a slightly inferior nutrient profile compared to the non-GMO variety.
The retailer was smart to suggest cutting back on highly processed, fractionated soyfoods (those made with soy isolates, for example) and functional foods spiked with soy derivatives. When choosing soy-based meat substitutes, look for reduced-calorie or low-fat products made with organic tofu or organic tempeh.