Antioxidant pills 'increase risk of early death'

More bad news for pill poppers and health freaks generally. The claim that antioxidants in food are somehow different is just deep faith. Note that in the madhouse that is the medical literature, a Cochrane study is unusually authoritative

Researchers at Copenhagen University carried out a review of 67 studies on 230,000 healthy people and found "no convincing evidence" that any of the antioxidants helped to prolong life expectancy. But some "increased mortality".

About 12 million Britons supplement their diets with vitamins and the industry is worth 330 million pounds. But little research has been done on the long-term health implications.

The Department of Health said yesterday that people should try to get the vitamins they need by eating a balanced diet and advised care in taking large doses of supplements. A spokesman said: "There is a need to exercise caution in the use of high doses of purified supplements of vitamins, including antioxidant vitamins, and minerals. Their impact on long-term health may not have been fully established and they cannot be assumed to be without risk. "Anyone concerned about their diet should speak to their doctor or dietitian."

Antioxidants, including vitamins A, E, C and beta-carotene and selenium, are said to mop up compounds, called free radicals, which cause disease. It is this action that researchers believe may cause problems with the defence system. The Danish research, released by the influential Cochrane Library, applied only to synthetic supplements and not to vitamins that occur naturally in vegetables and fruit.

It found that vitamin A supplements increased the risk of death in healthy people by 16 per cent. Taking beta-carotene was linked to a 7 per cent increased risk, while regular users of vitamin E supplements increased the risk of an early death by four per cent.

Although the review found no significant detrimental effect caused by vitamin C, it found no evidence that it helped ward off disease. Millions take it in the hope of avoiding a common cold.

Goran Bjelakovic, who led the review, said: "We could find no evidence to support taking antioxidant supplements to reduce the risk of dying earlier in healthy people or patients with various diseases. "If anything, people in trial groups given the antioxidants beta-carotene, vitamin A, and vitamin E showed increased rates of mortality."

But Patrick Holford, a nutritionist who has formulated supplements for the company Biocare, said: "Antioxidants are not meant to be magic bullets and should not be expected to undo a lifetime of unhealthy habits. "When used properly, in combination with a healthy diet full of fruit and vegetables, getting plenty of exercise and not smoking, antioxidant supplements can play an important role in maintaining and promoting overall health."

A spokesman for the Health Supplements Information Service said: "People should get all the vitamins and minerals they need from their diet, but for the millions who are not able to do that, vitamins can be a useful supplement and they should not stop taking them."

However, Catherine Collins, of the British Dietetic Association, said: "This study is deeply worrying and shows that there should be more regulation for vitamins and minerals. "The public can buy vitamins as easily as sweets. They should be treated in the same way as paracetamol with maximum limits on the dosage."

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Update:

My most frequent commenter has put up a long comment on this post in which he accused the Cochrane authors above of “cherry-picking” what they studied. Cherrypicking is indeed a common and often fatal flaw in meta-analyses but I would be surprised if Cochrane authors had done it irresponsibly.

I did not look closely at the study myself because the finding is one that was already well-substantiated. See here and here, for instance. It is true, however, that a single author -- Bjelakovic -- seems to be behind much of the review literature. That does not, however, erase the original studies that he reviews and his acceptance as a Cochrane reviewer indicates a judgment that his reviews are indeed representative.






Mumps outbreak

A large mumps outbreak in the United States in 2006 may have been caused by the failure of the vaccine, federal health experts reported Wednesday. In a study reported in the April 10 issue of the New England Journal of Medicine, authors urge a more effective mumps vaccine or changes in vaccine policy to eradicate the disease. The study found that 84 percent of people between the ages of 18 and 24 who became ill in the outbreak had received the second recommended dose. The national incidence of mumps was 2.2 per 100,000. The highest incidence was in persons 18 to 24 years of age, with an incidence 3.7 times that of all other age groups combined.

"Despite a high coverage rate with two doses of mumps-containing vaccine, a large mumps outbreak occurred, characterized by two-dose vaccine failure, particularly among Midwestern college-age adults who probably received the second dose as schoolchildren," the study authors wrote. "A more effective mumps vaccine or changes in vaccine policy may be needed to avert future outbreaks and achieve the elimination of mumps."

The authors conclude that further studies are needed to help evaluate national vaccine policy, including whether the administration of a second dose of MMR [measles-mumps-rubella] vaccine at a later age or the administration of a third dose would provide higher or more durable immunity.

Mumps is a disease caused by a virus that usually spreads through saliva and can infect many parts of the body, especially the parotid salivary glands. These glands, which produce saliva for the mouth, are found toward the back of each cheek, in the area between the ear and jaw. In cases of mumps, these glands typically swell and become painful. Mumps was common until the mumps vaccine was licensed in 1967. Before the vaccine, more than 200,000 cases occurred each year in the United States. Since then the number of cases has dropped to fewer than 1,000 a year, and epidemics have become fairly rare.

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