Total dietary antioxidant capacity and lung function in an Italian population: a favorable role in premenopausal/never smoker women.

BACKGROUND/OBJECTIVES: Antioxidant-rich foods may favorably influence lung function. We examined possible associations between the total dietary antioxidant capacity (TAC) and pulmonary function in a healthy Italian population. SUBJECTS/METHODS: Until May 2009, 22,300 persons were randomly recruited from the general population in the Moli-sani project. A sample only including healthy women (5824) and men (5848) was analyzed. TAC was measured in foods by three different assays and the ferric reducing-antioxidant power (FRAP) assay was selected as the better indicator of dietary TAC. The European Investigation into Cancer and Nutrition Food Frequency Questionnaire was used for dietary assessment. The association between quintiles of dietary FRAP and pulmonary indexes was assessed using analysis of variance separately for men and women. RESULTS: After adjustment for confounders, women in the highest quintile of FRAP intake had +39 ml forced expiratory volume in the first second (FEV(1)) and +54 ml forced vital capacity, compared with those in the lowest quintile (P for trend ≤0.006). Stratified analysis showed that this relationship only occurred in women who were premenopausal/never smokers. In this subgroup, the observed effect of higher FRAP intake on FEV(1) was equivalent to an improvement in pulmonary age of 3.3 years. In men, all significant associations between pulmonary function and TAC were lost after adjustment for confounding. CONCLUSIONS: Dietary TAC may have a favorable role in respiratory health, particularly in premenopausal/never smoker women.