Relationship between Dietary Factors and Prostate-Specific Antigen in Healthy Men

INTRODUCTION: There is little evidence indicating whether dietary factors influence prostate-specific antigen (PSA) concentrations. We examined whether nutritional factors, including energy, protein, fat, and carbohydrate intake were associated with PSA in healthy men. SUBJECTS AND METHODS: We investigated 13,594 men aged 50 years and over who visited a hospital for a routine health checkup between 2003 and 2007. Dietary intake was assessed using a food frequency questionnaire. We performed a multiple linear regression to examine the association between PSA and dietary intake. RESULTS: After controlling for age, body mass index, and physical activity, PSA was significantly negatively associated with percent protein intake (p for trend < 0.001). Compared with the lowest quintile, PSA was 5.8% lower (95% CI: -8.9 to -2.5%) in the highest quintile. We also observed a significant positive association between percent fat intake and PSA concentration (p for trend 0.043). PSA was 3.4% greater (95% CI: 0-6.9%) among men in the highest quintile compared with those in the lowest quintile. CONCLUSIONS: Men who had a lower percent protein intake and higher percent fat intake had an elevated PSA level, although the magnitude of these associations was small.