The advice from the Department of Health has been issued following a large review of scientific evidence published last year and advises caution over the use of Vitamin supplements.
Health officials say most people's nutritional needs are met by eating a balanced, varied diet including plenty of fruit and vegetables, and dietary supplements may do more harm than good.
The scientific review included 67 studies involving more than 230,000 people and has been republished by the Cochrane Collaboration, an international organisation for evidence-based research.
The review involved trials on beta-carotene, Vitamin A, Vitamin C, Vitamin E and selenium, with varying doses of each antioxidant.
The review found no evidence that the nutrition supplements extend life but found in fact that Vitamins A and E and beta carotene appear to slightly increase premature death rates among those taking them while Vitamin C and selenium have no effect.
The researchers say they found no evidence to support antioxidant supplements for primary or secondary prevention and beta-carotene, Vitamin A and Vitamin E given singly or combined with other antioxidant supplements significantly increase mortality.
The researchers say current evidence does not support the use of antioxidant supplements in the general healthy population or in patients with certain diseases.
They say more research on Vitamin C and selenium are needed and have called for more regulation of the health supplements industry and political action on the issue.
The Health Department says caution should be used in the use of high doses of purified supplements of Vitamins, including antioxidant Vitamins, and minerals, as their impact on long term health may not have been fully established and they cannot be assumed to be without risk.
Good sources of Vitamin A include cheese, eggs and oily fish; Vitamin E is found in foods such as soy, corn and olive oil; beta carotene is found in carrots, rockmelons, apricots and mangoes; Vitamin C is found in citrus fruits, strawberries, kiwifruit, capsicums, blackcurrants and potatoes; Selenium is found in meat, fish, shellfish, cheese and avocados.
The researchers fed the calorie restricted group a diet that was 30 percent lower in calories than that consumed by the overweight group and 50 percent lower than the obese group. Only 7.5 percent of mice on the calorie-restricted diet developed pancreatic lesions at the end of the experiment, and these lesions were so small that none exhibited symptoms of illness. For mice on the overweight diet, 45 percent developed lesions, as did 57.5 percent of those on the obesity-inducing diet. Lesions were also much larger in the overweight and obese mice than the calorie restricted mice.
While calorie restriction has been shown to have an anti-cancer effect in multiple species and for a variety of tumor types, its impact had not been well-studied in a model of pancreatic cancer. Pancreatic cancer is the fourth leading cause of cancer death and remains mostly intractable to existing treatments.
The decline in blood levels of inflammatory proteins in the calorie restricted mice makes sense, Lashinger notes, because fat tissue is a major source of inflammatory factors such as cytokines.
mdanderson/