Taking vitamin E will not prevent heart attacks or cancer, researchers said this week, news that could dent the current boom of one of the most widely consumed vitamins.
The extended Heart Outcomes Prevention Evaluation (HOPE-TOO) trial, involving 9,541 heart disease patients, found that the vitamin, which is thought to inhibit inflammation and help prevent narrowing of blood vessels, had the same effect on outcomes as those patients treated with placebo, said Dr Eva Lonn, associate professor of medicine at McMaster University in Hamilton, Canada. She was speaking at the European Society of Cardiology Congress in Vienna, Austria this week.
The randomised, double-blind, placebo-controlled, parallel group trial tested the effects of both the angiotensin-converting enzyme (ACE) inhibitor ramipril and vitamin E on the reduced risk of heart attack, stroke or cardiovascular death in high risk patients.
While the ramipril testing was stopped early due to clearly positive results, the vitamin E study continued to its term. After a seven-year intervention, 21.4 per cent of patients receiving the supplement experienced heart attack, stroke or cardiovascular death compared with 20.6 per cent of patients taking placebo, said Dr Lonn.
About 15.2 per cent of those taking vitamin E had a heart attack compared to 14.3 per cent of those on placebo, while 5.7 per cent of the vitamin E patients had a stroke compared with 5.1 per cent of those on placebo. Just over 10 per cent of those on vitamin E died from cardiovascular reasons compared with 9.9 per cent of those on placebo. None of the differences were significant, Dr Lonn said.
The results confirm another study carried out in the US, published in a recent issue of Circulation (19 August). This found tocopherols to have no preventative effect on heart attack in men taking them over a period of 13 years.
The McMaster University team also investigated the effects of vitamin E on cancer, but again there did not appear to be any statistical differences with placebo. However there was a statistically significant 17 per cent increase in the risk of congestive heart failure. "The lack of benefit of vitamin E on cancer and cardiovascular disease, coupled with the increase in heart failure raises concerns about the use of vitamin E," said Dr Lonn.
The vitamin is however increasingly being studied for its anti-ageing effects, with recent studies finding it may protect against progression of Alzheimer's disease.