Supplements �raise death rate

by 5%�

Nigel Hawkes, Health Editor

Vitamin pills commonly taken by millions of people are doing them more harm than good, an analysis of the evidence has concluded.

Three supplements � vitamins A and E and beta carotene � appear to increase death rates among those taking them. Vitamin C and selenium have no effect.

The results, published in The Journal of the American Medical Association, suggest that money spent on vitamin supplements is wasted. In response, the British Heart Foundation said people should not take supplements but should concentrate instead on eating a healthy diet.

The new study is a meta-analysis; a procedure in which many earlier studies are collected together. It was carried out by a team led by Goran Bjelakovic, of Copenhagen University Hospital, and colleagues, using methods developed by the Cochrane Collaboration, the leading international group specialising in the analysis of what works in medicine.

Supporters of vitamin supplements, which are consumed regularly by up to ten million Britons, believe these can act as antioxidants, preventing highly active oxygen radicals in the body-damaging molecules such as cholesterol causing heart disease. The theory seemed plausible, and some initial trial results appeared to lend it support. But as better trials were done different results emerged. The Copenhagen team considered 68 randomised control trials, involving 232,606 people, and published by October 2005. Of these, they rate 47 trials as being of the best quality, with the rest more prone to bias of one sort or another.

Taking only the 47 low-bias trials, involving 180,938 people, they found that supplements as a whole increased the death rate by 5 per cent. When the supplements were taken separately, beta carotene increased death rates by 7 per cent, vitamin A by 16 per cent, and vitamin E by 4 per cent. Vitamin C gave contradictory results, but when given singly or in combination with other vitamins in good-quality trials, increased the death rate by 6 per cent.

Selenium was the only supplement to emerge with any credit. It appears to cut death rates by 10 per cent when given on its own or with other supplements in high- quality trials, but the result is not statistically significant. The team concludes: �Our findings contradict the findings of observational studies claiming that antioxidants improve health.�

They say there are several possible explanations. One is that oxidative stress is not the cause of conditions such as heart disease for which it has been blamed, but may be a consequence of such conditions.

Alternatively, by eliminating free radicals we may interfere with essential defensive mechanisms. But the team adds that they examined only the use of synthetic vitamins, and their findings should not be translated to fruit and vegetables.

Ann Walker, of the Health Supplements Information Service, a body funded by the industry, said that the study combined the results of trials on two different classes of people: those with no known ill-health, and those already suffering from conditions such as heart disease. �The results of these mixed-sample metaanalyses are worthless,� she said.

Ellen Mason, a cardiac nurse at the British Heart Foundation, said: �There are good scientific reasons for believing that antioxidant supplements might protect against heart disease but a number of clinical trials have failed to provide any robust evidence in favour of this"

Vitamins raise death risk:

study

Popular vitamin supplements designed to prevent disease might actually increase the risk of death, a landmark international study has found.

Vitamin A performed worst in the 68-trial review, with the supplement said to lift mortality risk by 16 per cent.

A closely-related nutrient, beta carotene, had a 7 per cent rise.

Vitamin E supplements were associated with a 4 per cent increased risk, according to the Journal of the American Medical Association.

The Danish researchers found the top-seller, vitamin C, had no effect - positive or negative - on survival. The researchers also cleared the trace mineral selenium of increased risks.

They concluded "the public health consequences may be substantial" given that 10-20 per cent of Western adults swallow supplements regularly in the belief they're preventing disease.

The review examined the effects of beta carotene, vitamins A, E and C and selenium on the death of more than 230,000 adults involved in trials.

When looking at both low and high quality studies, they found no significant association between vitamin use and mortality.

But high-quality results analysed alone showed an average 5 per cent rise for the three supplements, vitamins A and E plus beta carotene.

Australian expert Luis Vitetta, from the Centre for Complementary Medicine and Research, said the results were "very concerning" and added strength to evidence that vitamins can do more harm than good.

"There's a billion dollar vitamin industry based on this idea that people can prevent disease when they're actually just putting themselves at extra risk," said Prof Vitetta, from the University of Queensland.

Supplement manufacturers claim these products have an antioxidant effect, essentially eliminating free radical "messenger molecules" that are responsible for the so-called oxidative stress which has been linked to disease.

But critics doubt whether oxidative stress even exists, with this research saying that killing off free radicals only interferes with some essential defensive mechanisms which affect survival.

Professor Vitetta said smaller studies had shown that those who "mega-dosed" on vitamins had the most heightened risk, and called for "very, very prudent" consumption.

He said doctors needed to be able to offer more concrete advice on vitamin intake, a call supported by the Australian Medical Association's John Gullotta.

"These results show this is an area of real concern that we should be looking at further," Dr Gullotta said.

The Complementary Healthcare Council (CHC), which represents the industry, said the results were based on old data and included trials which allowed doses of vitamins not accepted in Australia.

CHC executive director Tony Lewis would not comment on the study's claims but said the evidence was "weak".

Balz Frei, director of the Linus Pauling Institute at Oregon State University, said the study and the data studied were both flawed because more than two-thirds of the previous research that was examined involved people with heart disease, cancer or other risks who were being treated to see if the supplements worked.

"This kind of approach does not work," he said. "Over the years it has become clear from these clinical trials that antioxidants don't work in disease treatment."

The Natural Products Association, a supplement trade group, said the study "stands in stark contrast to large actual clinical studies that have not demonstrated any increased risks".

Daniel Fabricant, a vice-president of the association, said reviews of existing studies, called meta-analysis, often worked but in this case the process was biased because "there are many other factors that could contribute to mortality that were simply not assessed".

Supplements �raise death rate

by 5%�

Vitamins raise death risk:

study