9 Ways to Eat Healthier With Metastatic Breast Cancer

8. Safe and soy

“In the late ’90s and early 2000s, we heard a lot about soy and isoflavones, a class of phytoestrogens. So if a person was estrogen positive, research suggested soy would increase cancer growth,” Lanford says. “That research was conducted in rats, which don’t metabolize soy the way humans do.”
Later, it was thought that those isoflavones, predominantly found in legumes and beans, were a deterrent to breast cancer. Conversely, some worried that foods with soy might reduce potency of drugs that fight breast cancer, including tamoxifen.

In March 2017, a Tufts University study found that, “in specific circumstances,” eating more soy as part of an overall healthy diet could be beneficial. The research did not include supplements.

“Enjoy your soy by eating the whole plant, which has beneficial components,” says Lanford, who likes this AICR round-up on soy”