Review Finds Soy to Help Prostate Health

by | Apr 9, 2009 | 2009, Men's Health, Men's Health - Prostate, Soy Isoflavones

Written by Greg Arnold, DC, CSCS. In a review including 15 researches on nearly 172,000 patients, eating soybean foods once per day reduced the risk of prostate cancer by 71%. Soy isoflavones at 90 mg per day reduced prostate cancer risk by 52%.

After lung cancer, prostate cancer is the second leading cause of cancer deaths in American men (1).  The NIH estimated that the overall economic cost of cancer in the United States was $189.8 billion in 2004, with $69.4 billion attributed to direct medical costs, $16.9 billion to indirect morbidity costs, and $103.5 billion to indirect mortality costs (2).

Now a new study (3) has built upon findings in a 2006 study (4) and again found that soy may help prostate health.  In the study, researchers reviewed the current research (called a meta-analysis) on soy and isoflavone consumption and its association with prostate cancer risk in men.  They found 15 such studies that satisfied their criteria for credibility and included nearly 172,000 patients.  The researchers found overall soy intake to reduce prostate cancer risk by 26% and that this benefit ranged from > 240 grams of tofu per week producing a 20% reduced risk (5) to eating soybean food (soybeans, tofu, and miso) once per day producing a 71% reduced risk(6).

Regarding soy isoflavone intake, the greatest reduction in prostate cancer risk (52%) was seen with > 89.9 mg per day (7).  Of the 8 studies looking at isoflavone intake, 5 of the 8 measured total isoflavone intake (without breaking them down individually) and 3 looked at Genistein.  In the Genistein studies, those with more than 62 mg per day had a 48% reduced risk compared to 17.9 mg per day.

For the researchers, “consumption of soy foods is associated with a reduction in prostate cancer risk in men.”

Source: Yan, Lin, and Edward L. Spitznagel. “Soy consumption and prostate cancer risk in men: a revisit of a meta-analysis.” The American journal of clinical nutrition 89.4 (2009): 1155-1163.

© 2009 American Society for Nutrition

Posted April 9, 2009.

References:

  1. Stanford JL.  Prostate Cancer Trends 1973-1995, SEER Program, NIH Pub, No. 99-4543. Bethesda, MD: National Cancer Institute, 1999.
  2. Svatek RS. The Cost of Prostate Cancer Chemoprevention: A Decision Analysis Model.  Cancer Epidemiology Biomarkers & Prevention 2006;15:1485-1489.
  3. Yan L.  Soy consumption and prostate cancer risk in men: a revisit of a meta-analysis
    Published February 11, 2009; doi:10.3945/ajcn.2008.27029.
  4. Hedelin M.  Dietary Phytoestrogen, Serum Enterolactone and Risk of Prostate Cancer: The Cancer Prostate Sweden Study.  Cancer Causes and Control 2006; 17(2): 169-180.
  5. Jacobsen BK, Knutsen SF, Fraser GE. Does high soy milk intake reduce prostate cancer incidence? The Adventist Health Study. Cancer Causes Control 1998;9:553–7.
  6. Nomura AMY, Hankin JH, Lee J, Stemmermann GN. Cohort study of tofu intake and prostate cancer: no apparent association. Cancer Epidemiol Biomarkers Prev 2004;13:2277–9.
  7. Nagata Y, Sonoda T, Mori M, et al. Dietary isoflavones may protect against prostate cancer in Japanese men. J Nutr 2007;137:1974–9.