[SU.VI.MAX and NutriNet-Santé: lessons from large cohorts]

Su.vi.max and nutrinet-santé: lessons from large cohorts. This paper presents two epidemiologic studies in the field of nutrition, implemented in France for the last decades: an intervention trial (SU.VI.MAX) and a web-based prospective cohort study (NutriNet-Santé). The SU.VI.MAX study, a randomised, double-blind, placebo-controlled primary prevention trial, has shown that 7.5 years daily low-dose antioxidant supplementation (vitamins and minerals) lowered the total cancer incidence in men only, not in women. This may be explained by a lower baseline status of certain antioxidants (measured by blood concentration) in men compared to women. Finally, the effect of antioxidant supplementation on the incidence of cancer could depend on baseline antioxidant status (which differs from gender and/or nutritional status) and the health status of subjects (healthy vs cancer high-risk subjects). The NutriNet-Santé cohort is a web-based prospective cohort study launched in 2009 aiming to investigate the relationship between nutrition (nutrients, foods, dietary patterns, physical activity) and health outcomes; and to examine the determinants of dietary patterns and nutritional status (sociological, economic, cultural, biological, cognitive, perceptions, preferences, etc.).