Dairy intake in relation to prostate cancer survival

Dairy intake has been associated with increased risk of advanced prostate cancer. Two US cohort studies reported increased prostate cancer-specific mortality with increased high-fat milk intake. We examined whether dairy and related nutrient intake were associated with prostate cancer progression in a Swedish patient population with high dairy consumption. We prospectively followed 525 men with newly diagnosed prostate cancer (diagnosed 1989-1994). We identified and confirmed deaths through February 2011 (n = 222 prostate cancer-specific, n = 268 from other causes). Cox proportional hazards regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) for the associations between food or nutrient intake and prostate cancer-specific death. On average, patients consumed 5.0 servings/day of total dairy products at diagnosis. In the whole population, high-fat milk intake was not associated with prostate cancer-specific death (95% CI: 0.78, 2.10; p-trend = 0.32; multivariate-adjusted model). However, among patients diagnosed with localized prostate cancer, compared to men who consumed <1 servings/day of high-fat milk, those who drank ≥3 servings/day had an increased hazard of prostate cancer mortality (HR = 6.10; 95% CI: 2.14, 17.37; p-trend = 0.004; multivariate-adjusted model). Low-fat milk intake was associated with a borderline reduction in prostate cancer death among patients with localized prostate cancer. These associations were not observed among patients diagnosed with advanced stage prostate cancer. Our data suggest a positive association between high-fat milk intake and prostate cancer progression among patients diagnosed with localized prostate cancer. Further studies are warranted to investigate this association and elucidate the mechanisms by which high-fat milk intake may promote prostate cancer progression.