Seasonal change in antioxidant intakes and major food sources in overweight postmenopausal women

Abstract

Despite the emerging evidence on antioxidant benefits, no studies have documented seasonal variation of antioxidant intakes from diet. This study aimed to document seasonal change in antioxidant intakes and major food sources from usual diet using antioxidant food frequency questionnaires (Aox‐FFQ). Forty overweight postmenopausal women residing in Farmington, CT participated in a 9‐month observational study and completed an Aox‐FFQ every season. Seven‐day food records (FR) and 12‐h fasting blood samples at the first visit were collected for testing validity of Aox‐FFQ. Individual antioxidant intakes estimated by averaged 7‐d FR and the FFQ were moderately to highly correlated (r=0.34–0.78, P<0.05). Total α‐tocopherol and dietary carotenoid intakes were correlated with corresponding plasma concentrations (P<0.05). Intakes of most antioxidants assessed by the repeated FFQ were consistent over 9 months (p<0.05). Leading food sources contributing to antioxidant intakes, such as vegetables for carotenoids, fruits, fruit juices and vegetables for vitamin C, fruits, fruit juices, tea, vegetables and wine for flavonoids, fruits, fruit juices, tea and wine for proanthocyanidins were not affected by seasonal change, although the minor food contributors were fluctuated in different seasons. To conclude, there was no significant seasonal change in antioxidant intakes and major food sources in this study.Grant Funding Source: Donaghue Nutrition Research Program