New Research Developments in the News

EDITOR’S NOTE: The Integrative Medicine Alliance makes no endorsement of any business, organization, practitioner, therapy, or product described within this newsletter, nor is the information contained herein intended to be a substitute for medical advice. The appropriate use of vitamin E remains the subject of research and debate as indicated by the two releases below.

Additionally, please note that the IMA encourages anyone using herbal therapies or supplements to share the information with their health caregivers since many interactions are possible with standard medications. There are now, progressively available databases which list such interactions. Notifying your caregiver might prevent a possibly serious interaction. Encourage your caregivers to learn about such interactions.

High doses of vitamin E supplements MAY DO MORE harm than good

This story has been adapted from a news release issued by the American Heart Association

Daily vitamin E doses of 400 international units ("IU") or more can increase the risk of death and should be avoided, researchers reported at the American Heart Association’s Scientific Sessions 2004.

The study is simultaneously being released on the Web site of the Annals of Internal Medicine.

In animal and observational studies, vitamin E supplementation was shown to prevent cardiovascular disease and cancer.  However, other studies suggested that high doses could be harmful.

To determine if there is a “dose response,” researchers examined different doses of vitamin E supplements and risk of death from any cause.  They studied death rates in published clinical trials comparing vitamin E supplementation to placebo and included findings from 14 studies, from 1993 to 2004.  Doses ranged from 15 to 2000 IU/day, and average intake was about 400 IU a day.

“Increasing doses of vitamin E were linked to an increase in death,” said lead author Edgar R. Miller, M.D., Ph.D., associate professor of medicine at Johns Hopkins University in Baltimore, Md.

According to the analysis, there is no increased risk of death with a dose of 200 IU per day or less, and there may even be some benefit.  However, an increased risk was found at amounts above 200 IU per day and significant risk of death was found starting at 400 IU a day.  Those who take greater than 400 IU of vitamin E a day are about 10 percent more likely to die than those who do not, researchers said.

“Many people who take vitamin E supplements take between 400 and 800 IU in a single capsule,” said Miller.

The confusion for many, said Miller, is that some doctors have recommended vitamin E supplementation based on studies suggesting that it is beneficial for specific illnesses.  One study in people with a history of prior heart attack showed that vitamin E use correlated with a lower risk of having a second event.  In another trial, patients with end-stage kidney disease seemed to benefit.  However, in both of these studies (in fact, in seven of the eight high-dose vitamin E trials in this analysis) the patients on vitamin E supplementation were more likely to die than those in the placebo group.

“Typically, we get about 6-10 IU per day of vitamin E in our diets.   Vegetable oils, nuts and green leafy vegetables are the main dietary sources of vitamin E.   Supplementation can increase intake by 100-fold,” said Miller.             

Researchers said the current U.S. dietary guidelines do not recommend vitamin E supplementation, but indicate that the upper tolerable limit of intake is 1000 IU per day.

These findings parallel the findings of beta carotene supplementation trials.  Two major studies showed that beta carotene supplementation results in an increased risk for lung cancer and death.  And, as a result, "you will never see beta carotene supplements recommended again,” he said.

There is room for more research, however, on the effects of 200 IU or less per day of vitamin E and how low doses taken in combination with other vitamins might positively affect death rates, he said.

“The big questions that need to be answered are: What is the dose?   And how low a dose – in what combination – would be most useful?” Miller said. 

Co authors are Roberto Pastor-Barriuso Ph.D.; Darshan Dalal M.D., M.P.H.; Rudolph A. Riemersma Ph.D.; Lawrence J. Appel M.D., M.P.H. and Eliseo Guallar M.D., Dr.P.H.

For more information, visit http://www.americanheart.org  or copy and paste the following URL into your browser:

 http://www.americanheart.org/presenter.jhtml?identifier=3026060

VITAMIN E MAY HELP DIABETICS

This story has been adapted from a news release issued by Technion - Israel Institute of Technology.

According to a Technion-Israel Institute of Technology study published in the November 2004 Diabetes Care, about 40 percent of diabetic patients can reduce their risk of heart attacks and of dying from heart disease by taking vitamin E supplements.

The research team, led by Dr. Andrew Levy of the Faculty of Medicine, had earlier demonstrated that diabetics with a particular form of a blood protein called haptoglobin had as much as a 500% increased risk of developing heart disease. The new study shows that when these at-risk patients, who have the 2-2 form of haptoglobin, took 400 international units of vitamin E daily, they reduced their risk of heart attack by 43 percent, and their risk of dying of heart disease by 55 percent.

About 40% of diabetics have the 2-2 form of haptoglobin; the rest have the 1 -1 or 2-1 forms. When they took the same vitamin E supplements, they did not show any significant reduction of cardiovascular risk resulting from vitamin E therapy.

Dr. Levy's study analyzed serum samples that had been stored from the Heart Outcomes Prevention Evaluation (“HOPE”) trial of 2000, designed to study the effect of antioxidant therapy such as vitamin E on cardiovascular risk. The results of that study showed no benefit from vitamin E therapy on cardiovascular risk. However, Dr. Levy notes, the study did not segregate patients according to their haptoglobin type, analyzing instead the benefits of vitamin E in all patients. When he studied the serum samples from the HOPE study according to haptoglobin type, he found the greatly reduced risks noted above.

Now, a large-scale, five-year study of some 2,000 diabetics with haptoglobin 2-2, being conducted in northern Israel, is expected to corroborate Dr. Levy's findings.

"If this larger study confirms our findings, the public health implications will be huge. Vitamin E would represent an inexpensive and safe way to reduce the risk of cardiovascular death and heart attack in a significant proportion of diabetic patients," he said.

Dr. Levy had demonstrated in multiple previous studies that haptoglobin 2-2 is predictive of heart disease -- but only in people with diabetes. That's because diabetics tend to have more free radicals that destroy antioxidants. Furthermore, haptoglobin 2-2 is a very poor antioxidant when compared to the other haptoglobin types. This combination means that diabetics with haptoglobin 2-2 have an even greater deficiency of antioxidants than do diabetics with the other haptoglobin variants. Therefore, an increased supply of antioxidants, such as those found in vitamin E, would be expected to provide the greatest benefit for these patients.

The Technion-Israel Institute of Technology and the Kennedy-Leigh Charitable Trust is funding the new study. Dr. Levy is partial owner of a patent for a blood test that predicts susceptibility to diabetic vascular disease based on haptoglobin type.

The Technion-Israel Institute of Technology is Israel's leading science and technology university with a worldwide reputation for its pioneering work in computer science, biotechnology, water-resource management, materials engineering, aerospace and medicine. Based in New York City, the American Technion Society is the leading American organization supporting higher education in Israel, with more than 20,000 supporters and 17 offices around the country.

 
For more information: http://www.technion.ac.il/