Antioxidant-rich food intakes and their association with blood total antioxidant status and vitamin C and E levels in community-dwelling seniors from the Quebec longitudinal study NuAge.

A cross-sectional study was designed to investigate the association between current consumption of a series of 26 common antioxidant-rich foods (ARF) with serum total antioxidant status (TAS) and plasma vitamin C and E levels in community-dwelling older adults. A convenience sample of the first 94 non-smoking Caucasian men (54%) and women (46%) enrolled in the Quebec Longitudinal Study NuAge were selected. The "Functional Foods Consumption Frequency Questionnaire" (FFCFQ) was administered at recruitment (T1) to ascertain patterns of consumption of ARF over the lifetime. The total Oxygen Radical Antioxidant Capacity (ORAC) of 25 ARF reported by subjects was estimated using published values. Serum TAS was determined based on the Trolox equivalent antioxidant capacity (TEAC) assay while plasma vitamins C and E (α- and γ-tocopherol) levels were analyzed by HPLC. The numbers of ARF eaten daily at T1, estimated from the FFCFQ and calculated from the diet recalls, were significantly correlated (r=0.51, P<0.0001) and each measure was associated with total ORAC content (r=0.34, P<0.001 and r=0.59, P<0.0001 for FFCFQ and recalls, respectively). No significant association was found between TAS and the total ORAC value of ARF determined from the quantitative 24-h diet recalls. However, daily ARF consumption at T1 obtained from the FFCFQ was significantly and positively correlated with TAS (r=0.26, P<0.05) and circulating levels of vitamin C (r=0.25, P<0.02) and α-tocopherol (r=0.22, p<0.05) and negatively correlated with plasma γ-tocopherol (r=-0.25, P<0.025). These results highlight associations between ARF consumption and circulating levels of antioxidants in the elderly and suggest benefits from antioxidant-rich foods during aging.