What about soy food intake and breast cancer survival? We didn’t have a clue, until 2009, when the LACE study was published—Life After Cancer Epidemiology.

About 2,000 California breast cancer survivors followed for nine years. Postmenopausal women, on the estrogen–blocking drug tamoxifen, who got the most of this soy isoflavone in their diet had the lowest rate of breast cancer recurrence—appeared to cut breast cancer recurrence in half. Soy was, if anything, protective. But you can’t just sprinkle some soy sauce. It took soy levels “comparable to those consumed in Asian populations”—one or two servings a day—to reduce the risk of occurrence.

Then came the famous Journal of the American Medical Association study, the biggest yet—5,000 breast cancer survivors. Conclusion: “Among women with breast cancer, soy food consumption was significantly associated with decreased risk of death and recurrence.”

Now this isn’t taking soy isoflavone supplements; this was actually eating soy foods. “[T]he potential benefits are confined to soy foods, and inferences should not be made about the risks or benefits of soy-containing dietary supplements. Patients with breast cancer can be assured that enjoying a soy latte or indulging in pad thai with tofu causes no harm, and, when consumed in plentiful amounts, may reduce [the] risk of disease recurrence.”

And then, finally, 2011: “Soy Food Consumption and Breast Cancer Prognosis.” A third study—the only three such studies in existence—and soy is three for three. “As isoflavone intake increased, risk of death decreased.” What more do we need to know?

To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by veganmontreal.

Please consider volunteering to help out on the site.