Researchers Say Taking Certain Vitamins Can Shorten Lifespan

As health conscious consumers, we are mindful of the need to eat a balanced diet. But with hectic lifestyles and little time to spare, many people choose to opt for dietary supplements instead, as a safe and effective alternative. But just how safe are our dietary supplements?

Antioxidant supplements such as vitamin A, E and beta-carotene are taken by millions worldwide. Researchers at Copenhagen University in Denmark have looked at dozens of previous studies that were carried out and come to the conclusion that these vitamin supplements appeared to raise, rather than lower, the risk of early death.

A supplements industry expert remarked that the Journal of the American Medical Association contained flaws. In response, nutritionists have stated that the findings revealed the need to eat a balanced diet, rather than rely so much on dietary supplements. Even though vitamin supplements have been in popular demand for decades, the actual benefits that they offer, still remains a mystery, despite hundreds of research projects that have been carried out.

A more recent theory suggests that some vitamins that are taken in conjunction with a balanced diet, perhaps even in supplement form, could actually help prevent damage to the body's tissues, called 'oxidative stress', by getting rid of the molecules called 'free radicals', that are believed to cause it. The damage caused in this process has been linked to cancer and heart disease. The theory that vitamin supplements could protect people from these diseases has not been fully proved.

The Copenhagen study team looked at 815 clinical trials and reviewed the benefits of vitamins A, E, and C, as well as beta-carotene and selenium. As previously mentioned, these supplements are commonly used. The team selected 68 whose methods had a higher likelihood of producing an accurate overall picture of the benefits of vitamins. They then added their results together to form one, large-scale study. Interestingly, this overview seemed to suggest that taking these anti-oxidant supplements did not increase or reduce the risk of early death. But when the researchers eliminated 21 trials, the results altered. The risk of death remained unchanged among selenium and vitamin C users; a significant increase of risk was present for the other three supplements. Beta-carotene produced an approximate 7% increased risk, vitamin E a 4% increase and vitamin A, a 16% increase.

The researchers wrote: "Our findings contradict the findings of observational studies claiming that antioxidants improve health. Considering that 10% to 20% of the adult population in Europe and North America may consume the supplements, the public health consequences may be substantial." The explanation for these increases in risk varies. They said that getting rid of 'free radicals' could actually interfere with the body's natural defense mechanism. They went on to call for further research into the effects of vitamin supplements on health.

Dr Frankie Phillips, a nutritionist at the British Dietetic Association, said that food contained different components which could not be replaced by supplements.
She said: "Our advice is to eat a wide range of foods in a balanced diet which can provide all of the nutrients the body needs to protect itself and combat diseases." Dr Ann Walker, of the Health Supplements Information Service, said the findings of the study were "worthless". She said that the studies examined by the Copenhagen Team were on patients who were already seriously ill. She stated: "How sensible scientists can suggest that a modest intervention of a single antioxidant supplement, can have a major effect in reversing life-threatening pathology, where patients already have advanced cardiovascular disease, is ridiculous".

As we can see, opinion remains divided over the results of these studies. Further studies may help to shed more light on this matter. In the meantime, consumers should continue to exercise caution and consult their doctor if they have any concerns over vitamin supplements. A balanced diet can help a person receive the nutrients that their body needs. But for some, supplements complement a lifestyle that cannot always support a balanced diet.

Source:

http://news.bbc.co.uk/2/hi/health/6399773.stm