Red and processed meat intake and cancer risk: Results from the prospective NutriNet-Santé cohort study

The International Agency for Research on Cancer (WHO-IARC) classified red meat and processed meat as probably carcinogenic and carcino genic for humans, respectively. These conclusions were mainly based on studies concerning colorectal cancer, but scientific evidence is still limited for other cancer locations. In this study, we investigated the prospective associations between red and processed meat intakes and overall, breast, and prostate cancer risk. This prospective study included 61,476 men and women of the French NutriNet Santé cohort (2009-2015) aged ≥35y and who completed at least 3 24h dietary records during the first year of follow-up. The risk of developing cancer was compared acro ss sex specific quintiles of red and processed meat intakes by multivariable Cox models. 1,609 first primary incident cancer cases were diagnosed during follow up, among which 544 breast cancers and 222 prostate cancers. Red meat intake was associated with increased risk of overall cancers (HR Q5vs.Q1 =1.31 (1.10–1.55), P trend =0.01) and breast cancer (HR Q5vs.Q1 =1.83 (1.33–2.51), P trend =0.002). The latter association was observed in both premenopausal (HR Q5vs.Q1 =2.04 (1.03 4.06)) and postmenopausal women (HR Q5vs.Q1 =1.79 (1.26 2.55)). No association was observed bet ween red meat intake and prostate cancer risk. Processed meat intake was relatively l ow in this study (cut offs for the 5 th quintile=46g/d in men and 29g/d in women) and was n ot associated with overall, breast or prostate cancer risk. This large cohort study suggested that red meat may be involved carcinogenesis at several cancer locations (other than colon rectum), in particular breast cancer. These results are consistent with mechanistic evidence from experimental studies