DAVID E. STEVENSON

The New Zealand Institute for Plant and Food Research Limited
Plant & Food Research Ruakura, Private Bag 3230, Waikato Mail Centre, Hamilton, 3240, New Zealand

Abstract

Recent research indicates that antioxidants do not work in quite the way we thought, but may still have beneficial health effects through helping the body respond to and manage oxidative stress (covered in Part 1). This has prompted a rethink of antioxidants in the diet and how we can use them beneficially in the foods we eat. We discuss some examples of new science-based approaches to improving human health and the development and proof of efficacy of future functional foods targeted at assisting the benefits of physical exercise and slowing of the human ageing process.

INTRODUCTION
The findings from recent research suggesting dietary polyphenols may help to manage oxidative stress and our current understanding of how this is achieved were covered in Part 1. Now we look at the body of knowledge around the potential health benefits arising from this property of polyphenols and suggest how this knowledge could be used both to devise new functional food concepts and to provide convincing scientific support for health claims.

HEALTH BENEFITS FROM POLYPHENOL-INDUCED MITOCHONDRIAL RESPONSES

Animal trials linking polyphenols with healthy or health-promoting mitochondrial responses
Intervention studies in mice have found that dietary resveratrol reversed all the harmful biological changes (in particular, a shortened lifespan) induced by a high calorie diet and consequential weight gain and also increased the activity of MB signalling pathways (1, 2). Another study found increases in the major antioxidant enzymes in mice (3), including a doubling of MnSOD activity in mitochondria. Furthermore, a naturally-occurring derivative of resve ...