The effect of walnut intake on factors related to prostate and vascular health in older men.

BACKGROUND: Tocopherols may protect against prostate cancer and cardiovascular disease (CVD). METHODS: We assessed the effect of walnuts, which are rich in tocopherols, on markers of prostate and vascular health in men at risk for prostate cancer. We conducted an 8-week walnut supplement study to examine effects of walnuts on serum tocopherols and prostate specific antigen (PSA). Subjects (n = 21) consumed (in random order) their usual diet +/- a walnut supplement (75 g/d) that was isocalorically incorporated in their habitual diets. Prior to the supplement study, 5 fasted subjects participated in an acute timecourse experiment and had blood taken at baseline and 1, 2, 4, and 8 h after consuming walnuts (75 g). RESULTS: During the timecourse experiment, triglycerides peaked at 4 h, and gamma-tocopherol (gamma-T) increased from 4 to 8 h. Triglyceride - normalized gamma-T was two-fold higher (P = 0.01) after 8 versus 4 h. In the supplement study, change from baseline was +0.83 +/- 0.52 micromol/L for gamma-T, -2.65 +/- 1.30 micromol/L for alpha-tocopherol (alpha-T) and -3.49 +/- 1.99 for the tocopherol ratio (alpha-T: gamma-T). A linear mixed model showed that, although PSA did not change, the ratio of free PSA:total PSA increased and approached significance (P = 0.07). The alpha-T: gamma-T ratio decreased significantly (P = 0.01), partly reflecting an increase in serum gamma-T, which approached significance (P = 0.08). CONCLUSION: The significant decrease in the alpha-T: gamma-T ratio with an increase in serum gamma-T and a trend towards an increase in the ratio of free PSA:total PSA following the 8-week supplement study suggest that walnuts may improve biomarkers of prostate and vascular status.

Effect of cow milk on food folate bioavailability in young women.

BACKGROUND: The findings of animal and human studies suggest that a certain component in milk enhances food folate bioavailability. OBJECTIVE: The objective was to evaluate whether cow milk enhances the bioavailability of food folate in humans. DESIGN: Thirty-one young women were fed low-folate diets on a 4-d rotation with (n=17) or without (n=14) cow milk for 8 wk. Plasma and erythrocyte folate and plasma total homocysteine (tHcy) concentrations were monitored. RESULTS: Plasma folate concentrations steadily declined in both the milk and the nonmilk groups; however, the declines were not significantly different between groups (P=0.09). In contrast, erythrocyte folate concentrations declined only in the nonmilk group and remained unchanged in the milk group; the difference between the 2 groups was significant (P=0.01). Plasma tHcy concentrations significantly increased in the nonmilk group and remained unchanged in the milk group; the difference between the 2 groups was significant (P=0.02). CONCLUSION: The inclusion of cow milk in the diet enhanced the bioavailability of food folate as assessed by the changes in erythrocyte folate and plasma tHcy concentrations but not in plasma folate concentrations. The mechanisms of action by the components of cow milk remain to be investigated.

Effects of moderate-fat (from monounsaturated fat) and low-fat weight-loss diets on the serum lipid profile in overweight and obese men and women.

BACKGROUND: Little evidence of the effects of moderate-fat (from monounsaturated fat) weight-loss diets on risk factors for cardiovascular disease exists because low-fat diets are typically recommended. Previous studies in weight-stable persons showed that a moderate-fat diet results in a more favorable lipid and lipoprotein profile (ie, lower serum triacylglycerol and higher HDL cholesterol) than does a low-fat diet. OBJECTIVE: We evaluated the effects of energy-controlled, low-fat and moderate-fat diets on changes in lipids and lipoproteins during weight loss and subsequent weight maintenance. DESIGN: We conducted a parallel-arm study design in overweight and obese [body mass index (in kg/m(2)): 29.8 +/- 2.4] healthy men and women (n = 53) assigned to consume a low-fat (18% of energy) or moderate-fat (33% of energy) diet for 6 wk to achieve weight loss, which was followed by 4 wk of weight maintenance. All foods were provided and body weight was monitored to ensure equal weight loss between groups. RESULTS: The moderate-fat diet elicited favorable changes in the lipoprotein profile. Compared with baseline, HDL cholesterol was unchanged, whereas triacylglycerol and the ratios of total and non-HDL cholesterol to HDL cholesterol were lower at the end of the weight-maintenance period in the moderate-fat diet group. Despite similar weight loss, triacylglycerol rebounded, HDL cholesterol decreased, and the ratios of total and non-HDL cholesterol to HDL cholesterol did not change during the 10-wk interval in the low-fat diet group. CONCLUSIONS: A moderate-fat weight-loss and weight-maintenance diet improves the cardiovascular disease risk profile on the basis of favorable changes in lipids and lipoproteins. There is merit in recommending a moderate-fat weight-loss diet.