| The last year hasn't been a good one for vitamin E. | | | | Analyzing data from the Women's Health Study, a |
| Once considered a wonder supplement, an | | | | trial involving 40,000 women who got either 600 IU |
| inexpensive and harmless pill that might prevent heart | | | | of vitamin E every other day or a placebo, |
| disease, cancer and Alzheimer's, a flurry of recent | | | | researchers found that it provided no overall |
| clinical trials suggest it does none of those things. | | | | cardiovascular benefit such as reduction in heart |
| Some even suggest there is a small chance it could | | | | attacks or strokes. |
| be harmful in higher doses. | | | | However, an analysis of a subgroup of women over |
| Yet while the oily little capsule apparently can't keep | | | | 65 found a 26% reduction in cardiovascular events. |
| people alive longer, it refuses to die, in part because | | | | Buring said that although the finding was "intriguing," it |
| in nearly every one of the recent negative studies | | | | was not supported by previous research. |
| some caveat or contradictory finding creates a | | | | She added that it needs confirmation. |
| glimmer of hope. | | | | Adding even more confusion, the study found a |
| It also doesn't hurt that the dietary supplement | | | | statistically significant 24% reduction in cardiovascular |
| industry continues to promote vitamin E and offers | | | | deaths among all the vitamin E users. |
| experts to refute some of new research. | | | | Buring also questioned that finding because there was |
| "It doesn't go away," said Edgar Miller, a vitamin E | | | | no overall reduction in strokes and heart attacks. She |
| researcher and associate professor of medicine at | | | | said it was possible that it was due to other |
| Johns Hopkins University. "Why does it keep selling | | | | cardiovascular causes such as arrhythmias or heart |
| when there are so many of these negative studies?" | | | | failure, but there was no reasonable biological |
| The answer appears to be a combination of factors, | | | | explanation for that. |
| including years of promising laboratory, animal and | | | | "People should look at that further, but it could be |
| epidemiological studies; heavy promotion by the | | | | chance," she said. |
| dietary supplement industry; and, more recently, | | | | Buring concluded that vitamin E was neither harmful |
| contradictory findings within studies showing no | | | | nor beneficial in preventing cardiovascular disease. |
| overall benefit. | | | | A surprise |
| The required daily amount is 22 IU (international units). | | | | About a week after the Women's Health Study, |
| Many recent clinical trials have ranged from 300 IU to | | | | another controversial vitamin E finding was presented. |
| 2,000 IU. | | | | The study involved 9,500 people aged 55 and older |
| Recent clinical trials of high-dose vitamin E have led | | | | with vascular disease or diabetes who were followed |
| some researchers to speculate that vitamin E in | | | | for an average of seven years. |
| megadoses may increase the oxidation of LDL | | | | It found that 400 IU of vitamin E a day provided no |
| cholesterol, the bad kind. | | | | protection against cancer or major vascular events |
| When cholesterol is oxidated, it contributes to | | | | such as heart attacks or strokes. |
| coronary artery disease. | | | | In addition, the study found a disturbing 13% increase |
| There also is some concern that high amounts of | | | | in heart failure cases and 21% increase in heart failure |
| vitamin E may displace other beneficial anti-oxidants | | | | hospitalizations. |
| from that average person's diet. | | | | That was the first time that vitamin E had been |
| Combining studies | | | | associated with an increased risk of heart failure, said |
| Consider these recent studies: In November, a | | | | lead author Eva Lonn, a professor of medicine at |
| vitamin E bombshell was dropped by Johns Hopkins | | | | McMaster University in Hamilton, Ontario. |
| University researchers at an American Heart | | | | "I am not convinced about the harm," Lonn added. |
| Association meeting. | | | | Indeed, a recent small study of heart failure patients |
| They pooled 19 clinical trials of vitamin E involving | | | | taking a cholesterol-lowering statin drug suggested |
| 136,000 patients. | | | | that vitamin E actually increased the statin's ability to |
| In 11 of the high-dose trials (400 IU or more), the risk | | | | improve blood vessel function and lower inflammation. |
| of dying from any cause increased 4%, compared | | | | Lonn and the other researchers said a review of all |
| with people taking placebos. | | | | heart failure events in large vitamin E clinical trials "is |
| Prior to that finding, vitamin E had been considered, | | | | strongly recommended." |
| at worst, harmless. | | | | Confounding the heart failure finding was what |
| "People take anti-oxidants because they want to live | | | | appeared to be a statistically significant 28% |
| longer," said Miller, an associate professor of medicine. | | | | reduction in lung cancer cases, although in a |
| "What we showed is you don't live longer." | | | | secondary analysis of the data the benefit seemed |
| However, the analysis also suggested that lower | | | | to disappear. |
| doses of vitamin E (less than 150 I.U. a day) were | | | | "The numbers are small," Lonn said. "We think it's a |
| associated with about a 2% reduction in deaths. | | | | chance finding." |
| Researchers acknowledged several potential | | | | The researchers noted that other larger vitamin E |
| shortcomings in their study. | | | | trials showed no lung cancer benefit. |
| For instance, they noted that several of the | | | | Alzheimer's research |
| high-dose trials involved people with various chronic | | | | There still is some hope that vitamin E might help |
| diseases and may not apply to healthy individuals. | | | | prevent Alzheimer's disease, although in May a clinical |
| They also said the small size of several of the trials in | | | | trial of 769 patients with mild cognitive impairment |
| the analysis and inconsistent reporting of health | | | | found it was of no benefit in delaying the progression |
| events prevented a detailed look at the effect of | | | | to Alzheimer's. |
| various doses of the vitamin. | | | | In that trial, the patients took a mega dose 2,000 IU |
| "It's a very flawed analysis," said Julie Buring, a | | | | a day for up to three years, according to the findings |
| professor of medicine at Harvard Medical School who | | | | in the New England Journal of Medicine. |
| recently presented her own vitamin E research. | | | | Other vitamin E / Alzheimer's trials are ongoing. |
| She also said the 4% increased risk of death was | | | | The anti-oxidant vitamin enthusiasm of the 1990s is |
| not "clinically meaningful" and could be a chance | | | | being tempered by clinical trials, according to a JAMA |
| finding. | | | | editorial that accompanied the Women's Health Study |
| Women's health study | | | | results. |
| On March 7, Buring and other Harvard scientists | | | | "These hopes are now confined to modest |
| presented their own vitamin E study at the American | | | | expectations for specific disorders and there are |
| College of Cardiology annual meeting. | | | | concerns about adverse effects," the editorial said. |
| Once again, the vitamin threw researchers a curve. | | | | |