Improvement of diet sustainability with increased level of organic food in the diet: findings from the BioNutriNet cohort

Organic food consumption has steadily increased over the past decade in westernized countries. The aim of this study, based on observational data, was to compare some sustainability features of diets from consumers with varying levels of organic food. The diet sustainability among 29,210 participants of the NutriNet-Santé study was estimated using databases developed within the BioNutriNet project. Four dimensions (nutrition, environment, economy, and toxicology) of diet sustainability were assessed using: 1) nutritional indicators through dietary intakes and dietary scores, and BMI; 2) environmental indicators (greenhouse gas emissions, cumulative energy demand, and land occupation); 3) economic indicators via diet monetary costs; and 4) estimated daily food exposures to 15 pesticides. Adjusted means (95% CI) across weighted quintiles of organic food consumption in the diet were estimated via ANCOVA. Breakdown methods were used to disentangle the contribution of the production system (organic compared with conventional) from the dietary pattern in the variation of diet-related environmental impacts, monetary costs, and pesticide exposure, between the 2 extreme quintiles. Higher organic food consumption was associated with higher plant-food and lower animal-food consumption, overall nutritional quality (higher dietary scores), and lower BMI. Diet-related greenhouse-gas emissions, cumulative energy demand, and land occupation gradually decreased with increasing organic food consumption, whereas total diet monetary cost increased. Diet exposure to most pesticides decreased across quintiles. Diets of high organic food consumers were generally characterized by strong nutritional and environmental benefits. The latter were mostly driven by the low consumption of animal-based foods, whereas the production system was responsible for the higher diet monetary costs, and the overall reduced dietary pesticide exposure.