What You Need to Know: Daily consumption of a soy protein powder beverage for 2 years failed to delay or prevent disease recurrence in men who had undergone surgery (radical prostatectomy) for prostate cancer, according to a randomized, double blind trial.
Background: Soy consumption has been suggested as a means to lower your risk of prostate cancer recurrence. Still, we didn’t have much data to guide us; that is, until now. Roughly half of men with prostate cancer use dietary supplements including soy. But should they?
The Current Study: 177 men at high risk for cancer relapse were treated across 7 centers between July 1997 and May 2010. All patients received a 20 gram protein powder (to be put into a drink) that contained either soy protein isolate or a placebo (calcium caseinate). Supplements began months after surgery and continued up to 2 years. Investigators then checked PSA blood measurements every 2 months for the first year, and every 3 weeks thereafter. The trial was halted early, as the soy did not appear to have any effects on recurrence.
My Take: This study provides high level evidence that you should not use soy as a means to reduce the risk of prostate cancer recurrence following prostate cancer surgery (radical prostatectomy). Perhaps a lifetime of exposure might reduce the risk of prostate cancer, but even that is highly speculative.
The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.
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Reference: Bosland MC. JAMA. 2013;310:170-178.