Antioxidants and the prevention of cancer

It has been estimated that Australians spend approximately $4 billion annually on complementary and alternative medicine (CAM; includes purchases of products and visits to practitioners), just under half of which is spent on CAM products.1 Spending on CAM products equates to roughly half of all non-subsidised health care products in Australia.1,2 The most frequently purchased CAM product type in Australian representative surveys is clinical nutrition, accounting for 50% to 60% of CAM product usage.1,3 CAM is most often used to improve general health, in the belief that dietary supplementation is useful to prevent chronic disease. Following the release of results from observation trials suggesting that a high dietary intake of fruits and vegetables is associated with reduced cancer incidence and mortality,4–6 there has been a strong awareness that intakes of some nutrients beyond the recommended daily intake may have a role in the prevention of many diseases. Diet is thought to play a significant role in the development of many diseases, including cardiovascular disease, stroke, macular degeneration, dementia and cancer. This article will briefly review the recent evidence surrounding the use of diet and dietary supplements to prevent cancer.