Soy: Health Food or Health Hazard?

For many vegetarians, soy products such as tofu and tempeh provide a valuable source of protein. And now soy has entered the mainstream. Even meat-eaters may crack open an edamame pod or slip soy milk into their coffee.

Soy advocates tout its low levels of saturated fat and a potential link to better heart health. Meanwhile, darker headlines have hinted at a connection between soy and cancer risk. What’s the truth?

Exploring the Perks

Some research has shown eating soy daily lowers levels of low-density lipoprotein (LDL), or “bad,” cholesterol. And some women seem to find relief from hot flashes when they take soy supplements—available as tablets or capsules—during menopause.

Researchers are currently studying whether compounds in soy, called isoflavones, help heart health, prevent bone loss and even prevent some cancers. This includes breast and prostate tumors.

Understanding the Risks

On the flip side, however, isoflavones act like estrogen in the body. Certain types of breast tumors need estrogen to grow. So some scientists worry that consuming soy can promote, rather than protect against, these breast cancers.

Thus far, the research suggests it’s safe for women—including breast cancer survivors—to eat soy. Experts at the National Cancer Institute caution that the picture continues to evolve. If you’ve had breast cancer or are at high risk, talk with your doctor.

Soy’s Bottom Line

Some people have a soy allergy that causes a rash, stomachache or stuffy nose. This most often occurs in children, who tend to outgrow it by age 10.

Everyone else can consider soy one of many healthy proteins. Regularly rotating between animal- and plant-based sources adds nutritious variety to your meals. Stick to whole-food products, such as soybeans, tofu and tempeh. Talk with your doctor before taking supplements.