Dietary intakes of carbohydrates in relation to prostate cancer risk: a prospective study in the Malmö Diet and Cancer cohort.

BACKGROUND Dietary carbohydrates have been implicated in relation to prostate cancer. OBJECTIVE Our objective was to examine the associations between dietary intakes of carbohydrates, fiber, and their food sources and risk of prostate cancer, overall and by case severity, in the Malmö Diet and Cancer cohort. DESIGN The analysis included 8128 men aged 45-73 y without a history of cancer, cardiovascular disease, or diabetes and who were classified as adequate energy reporters. After a median follow-up time of 15 y, prostate cancer was diagnosed in 817 men. We used Cox proportional hazards regression to model associations between energy-adjusted nutrient and food intakes with risk of incident prostate cancer, with competing risk of death from non-prostate cancer causes taken into account. RESULTS After adjustment for age and other known or potential risk factors, we observed no associations between total carbohydrates or dietary fiber and prostate cancer. We observed positive associations between the intake of low-fiber cereals with overall and low-risk prostate cancer and between intakes of cake and biscuits and rice and pasta with low-risk prostate cancer (all P-trend < 0.05). A high intake compared with zero consumption of sugar-sweetened beverages was associated with increased risk of symptomatic prostate cancer (HR: 1.38; 95% CI: 1.04, 1.84). CONCLUSIONS Results from this large study with high-validity dietary data suggest that a high intake of refined carbohydrates may be associated with increased risk of prostate cancer. However we observed no significant associations with high-risk prostate cancer, and not all foods that are typically high in refined carbohydrates were associated with prostate cancer.