Association between grain intake and prostate-specific antigen: A cross-sectional study from US men

Previous studies investigating the association between grain intake and prostate-specific antigen (PSA) levels have yielded inconsistent results. This study aimed to clarify the associations between whole grain and refined grain intake and serum PSA levels. We analyzed cross-sectional data from the National Health and Nutrition Examination Survey for the years 2001 to 2010. The study population comprised male participants aged 40 years and older, consistent with the National Health and Nutrition Examination Survey PSA measurement protocol. This dataset included complete demographic characteristics, grain intake data, and PSA measurements. 5639 participants were ultimately included. Multivariate weighted linear regression analyses revealed a significant inverse association between whole-grain intake and PSA levels. In contrast, refined grain intake was not significantly associated with PSA in either continuous or categorical analyses (all P > .05). A significant overall linear association was observed between whole-grain intake and total PSA (P overall = .0294), with no evidence of nonlinearity (P nonlinear = .1165). This inverse association was consistent across subgroups stratified by age, body mass index, drinking status, smoking status, diabetes, and hypertension (all P for interaction >.05). In summary, in contrast to refined grain intake, whole-grain intake may play a protective role in maintaining prostate homeostasis, as reflected by lower PSA levels. These findings provide novel insights for the prevention and management of patients at high risk of elevated PSA and offer guidance for dietary recommendations.