Association between a pro plant-based dietary score and cancer risk in the prospective NutriNet-santé cohort

Diverse plant products (e.g. fruits, vegetables, legumes) are associated with decreased cancer risk at several locations while red and processed meat were found to increase cancer risk. A pro plant‐based dietary score reflecting the relative contribution of consumed plant vs animal products was developed, and was associated with lower overall mortality, type 2 diabetes and cardiovascular disease risk, among omnivorous adults. For the first time, we investigated the prospective associations between this pro plant‐based dietary score and cancer risk. This study included 42,544 men and women of the French NutriNet‐Santé prospective cohort (2009‐2016) aged ≥45 years who completed at least three 24‐hr‐dietary records during the first year of follow‐up. The risk of developing cancer was compared across sex‐specific tertiles of pro plant‐based dietary score by multivariable Cox models. In total, 1,591 first primary incident cancer cases were diagnosed during follow‐up, among which 487 breast, 243 prostate, 198 digestive and 68 lung cancers. A higher pro plant‐based dietary score was associated with decreased risks of overall (HR t3vs.t1 =0.85; 95% CI 0.76, 0.97; P trend =0.02), digestive (HR t3vs.t1 =0.68; 95% CI 0.47; 0.99; P trend = 0.04) and lung (HR t3vs.t1 =0.47; 95% CI 0.25, 0.90; P trend =0.02) cancer, though no substantial associations were found for breast or prostate cancers. This large cohort study supports a beneficial role of higher intakes of plant‐based products along with lower intakes of animal products, within a balanced omnivorous diet, regarding primary cancer prevention. These results are consistent with mechanistic evidence from experimental studies.