ABSTRACT: Background:While low-grade chronic inflammation has been suggested as a major modulator of healthy aging (HA), no study has yet investigated the link between the inflammatory potential of the diet and multidimensional concepts of HA. Objective:We aimed to evaluate the association between the inflammatory potential of the diet at midlife, as measured by the Dietary Inflammatory Index (DII), and HA assessed 13 y later. Methods:We analyzed data from 2796 participants in the French Supplémentation en Vitamines et Minéraux Antioxydants (SU.VI.MAX) study aged 45-60 y at baseline (1994-1995) and initially free of diabetes, cardiovascular disease, and cancer. During the trial phase of the study (1994-2002), participants received either a placebo or a daily nutritional dose of antioxidant supplement (120 mg vitamin C, 6 mg ?-carotene, 30 mg vitamin E, 100 ?g Se, 20 mg Zn). HA was assessed in 2007-2009, and defined as having no major chronic disease, good physical and cognitive functioning, independence in daily activities, no depressive symptoms, good social health, good overall self-perceived health, and no function-limiting pain. The DII was calculated based on repeated baseline 24-h dietary records. Its association with HA was assessed by robust-error-variance Poisson regression, providing RR estimates. Results:After adjustment for potential confounders, higher DII scores (reflecting a more proinflammatory diet), were associated with a decreased likelihood of HA: RRtertile 3/tertile 1 = 0.85 (95% CI: 0.74, 0.99); P-trend = 0.03. Secondary analyses revealed that this association was only significant among participants who had been in the placebo group during the trial phase: RRtertile 3/tertile 1 = 0.80 (95% CI: 0.64, 1.00); P-trend = 0.04. Conclusions:This study suggests that a proinflammatory diet may lower the probability of overall HA. The SU.VI.MAX trial was registered at www.clinicaltrials.gov as NCT00272428.