Wednesday, March 24, 2010

Facts About Vitamin E

Let’s talks about the facts about vitamin E. Since its discovery, there have been a lot of misconceptions and myths about this essential nutrient, so I want to present you the hard science and what we can honestly know about it. It was first discovered in 1922, as its deficiency caused sterility in laboratory rats. Early on, it was considered an aphrodisiac by many people, but, as you may know, there is a big difference between infertility and sexual desire. It was promoted as anti-aging, said to prevent wrinkles and impotence.

In the early 1990’s vitamin E was one of the most popular dietary supplements. It is actually an antioxidant and the thought was that it could reduce the incidence of heart disease and cancer. Some of the studies at the time suggested that, so consumers where driven to buy supplements. Vitamin E may actually have some role in the reduction of chronic disease, but now almost every major study suggests that this vitamin is not the hero we thought it was. Major studies have failed to show an association between vitamin E intake and the prevention of chronic disease.

Let’s turn to the hard facts about vitamin E. It is a fat-soluble vitamin and it is stored in body fat. Its primary role is as an antioxidant. An antioxidant stabilizes cell membranes and protects them from oxidation. It protects lung membranes from environmental contaminants, it prevents mutations in DNA and also protects from cardiovascular disease by protecting lipid from being oxidized. Keep in mind that it is the oxidized LDL that is so lethal.

Vitamin E is part of the family of compounds called tocopherols. The most common form of it is alpha-tocopherol. There are other forms of it that are absorbed, but they contribute much less to the vitamin requirement than alpha-tocopherol.

Vitamin E and Heart Disease

Interest in vitamin E was generated when observational and epidemiological studies suggested it might lower the risk of heart disease. One of the most convincing studies was published in 1993 and suggested that women who took vitamin E for more than two years had a 30% to 40% risk reduction of cardiovascular disease.

At that time, other international studies suggested that vitamin E was also associated with reduced heart disease risk, so it wasn’t just in the United States, it was worldwide. Then came the HOPE study. With the HOPE study, vitamin E’s wheels began to come off. HOPE stands for Heart Outcomes Prevention and Evaluation. This long term study evaluated the effectiveness of vitamin E. They studied individuals who had preexisting vascular disease like diabetes, so they were in their way to developing heart disease. Vitamin E was thought to prevent heart disease, so why not give it to the most vulnerable people and see its effectiveness?

The study was unique because it followed individuals for up to 7 years. They were taking 400 IU of vitamin E, more than the requirement. There was no benefit in the prevention of heart disease or cancer in this group of individuals. They were high risk individuals and there was no effectiveness. Furthermore, in individuals who were taking this extra vitamin E there was an increased risk of heart failure. Now we’ve got evidence that not only there is no benefit, but there is harm.

Preliminary research suggests vitamin E may aid in the preservation of cognitive function in Alzheimer’s disease. So, we’ve got some studies suggesting that this vitamin is good and others suggesting no.

A recent study by the American Cancer Society indicated that those who take vitamin E for 10 years can reduce the risk of bladder cancer. Observational studies suggest that maybe vitamin E and selenium together might be able to prevent prostate cancer. The SELECT study, however, which stands for Selenium and Vitamin E Cancer Prevention Trial, demonstrated that this combination is not effective as a prevention strategy.

We get again here this dichotomy of vitamin E. The bottom line is: get your vitamin E from food and stay away from supplements if you already have any vascular disease.

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