Total antioxidant capacity: A useful tool in assessing antioxidant intake status

Abstract

Total antioxidant capacity (TAC) considering the cumulative protective activities of all the antioxidants present in food was inversely associated with cardiovascular disease (CVD) risk factors, suggesting a great potential of dietary TAC as a useful dietary assessment tool in human clinical and intervention studies for assessing dietary antioxidant status and predicting plasma antioxidant defense. However, none of these factors has been successfully validated for relevance under different physiological conditions, or for reliability and predictability for in vivo antioxidant status. The objective of this study is to validate TAC as a useful dietary tool in assessing dietary antioxidant status. Forty postmenopausal, overweight and healthy women were recruited for an observational study. Seven day diet recalls and 12-h fasting blood samples were collected for dietary and plasma antioxidant assessments. Results: After multivariate adjustment, TAC from foods and TAC from foods and supplements were both positively associated with intakes of dietary antioxidants, including a-tocopherol (p ?< 0.001), vitamin C (p < 0.01), flavonoids (p < 0.001) and proanthocyanidins (p < 0.01); they were also positively associated with plasma TAC assayed by VCEAC, FRAP and ORAC methods (p < 0.05), and with plasma a-tocopherol (p < 0.0001), and b -cryptoxanthin (p < 0.01) concentrations. Fruits and fruit juices were the primary contributor to dietary TAC (from foods/foods and supplement) followed by tea and vegetable and vegetable juices. Conclusion: Dietary TAC could be used as a useful tool in predicting dietary and plasma antioxidant status.