Increasing the antioxidant content of food: a personal view on whether this is possible or desirable

Abstract

A commonly held belief is that higher intake of antioxidants will promote better health through enhanced antioxidant status and lowered oxidative stress. However, the benefits of antioxidant-rich foods have not been reproduced in supplementation trials with pure antioxidants. This has driven research and commercial interest in foods, including traditional foods and their components, with enhanced antioxidant content and improved antioxidant bioavailability, which in many cases is very low. In this paper, evidence for the health benefits of antioxidant-rich foods and methods to increase the antioxidant content and bioavailability of food antioxidants are reviewed briefly, and the concept that increased food antioxidant content/intake per se is beneficial is examined from a cautionary perspective, considering issues of low bioavailability, rapid catabolism, biotransformation and the paradoxical pro-oxidant effects of dietary antioxidants.

Keywords::

• polyphenols
• ascorbic acid
• FRAP assay
• food fortification
• bioavailability
• redox balance
• dietary antioxidants
• oxidative stress
• pro-oxidant

Declaration of interest: We are grateful to The Hong Kong Polytechnic University for supporting this work. We have no competing of conflicting interests.