Walnuts Good for Prostate Health?

COLLEGE PARK, Penn.—An eight-week study published in Nutrition Journal concluded walnuts may improve biomarkers of prostate and vascular status in older men (2008:7:13) (DOI: 10.1186/1475-2891-7-13). In random order, 21 subjects consumed their usual diet with or without a walnut supplement (75 g/d) isocalorically incorporated in their habitual diets. Prior to the supplement study, five fasted subjects participated in an acute time course experiment and had blood taken at baseline and 1, 2, 4, and 8 hours after consuming 75 g of walnuts. During the time course experiment, triglycerides peaked at four hours, and gamma-tocopherol increased from 4 to 8 hours. Triglyceride-normalized gamma-tocopherol was two-fold higher (P=0.01) after 8 versus 4 hours. In the supplement study, change from baseline was +0.83 +/- 0.52 micromol/L for gamma-tocopherol; -2.65 +/- 1.30 micromol/L for alpha-tocopherol; and -3.49 +/- 1.99 for the tocopherol ratio. A linear mixed model showed the ratio of free PSA to total PSA increased and approached significance (P=0.07). The alpha-tocopherol to gamma-tocopherol ratio decreased significantly (P=0.01), partly reflecting an increase in serum gamma-tocopherol, which approached significance (P=0.08). The scientists concluded walnuts may improve biomarkers of prostate and vascular status.