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Star Bulletin Alan Titchenal & Joannie Dobbs Health Options
Alan Titchenal
 & Joannie Dobbs
                  Monday, March 28, 2005

 

Vitamin E is in the hot seat again


VITAMIN E is good for the body, but scientific debate has heated up lately about how much should be consumed each day.

In a scientific review paper published last November, high dosage vitamin E supplementation was questioned. The collective data from multiple studies involving more than 135,000 study participants indicated a greater number of deaths in those taking higher doses of vitamin E.

Another study published in the current issue of Journal of the American Medical Association reports little or no difference in the incidence of cancers and heart attacks between patients given a natural source of vitamin E or a placebo. However, those taking the 400 IU vitamin E supplement had an increased incidence of heart failure and hospitalizations due to heart failure compared to the placebo group.

Question: What is heart failure?

Answer: Heart failure is a condition in which the heart loses its ability to pump blood efficiently because the heart muscle has weakened. The condition causes fluid to accumulate in the lungs, hands, ankles, or other parts of the body. Heart failure is also called congestive heart failure.

Q: Did the excess vitamin E cause the heart failure?

A: The study cannot draw this conclusion. Many people in the placebo group also had heart failure and all of the 9,541 people in the study were older than 55 and already had vascular disease or diabetes at the start of the study.

Q: Does the study indicate that taking vitamin E is dangerous?

A: No, but the safety of high intake of any single antioxidant is questionable, especially at levels greatly exceeding recommendations.

Q: What is an antioxidant?

A: Antioxidants are naturally occurring nutrients and food chemicals that help to prevent cellular damage associated with the normal aging process. Antioxidants work by binding to destructive compounds called free radicals. If free radicals are left unchecked, they can cause damage to the heart muscle, promote cataracts or even cancer. Likewise, the immune system is weakened by inadequate antioxidants.

An excess of antioxidants also may cause damage. Typical nutrients that have antioxidant functions are vitamin C, vitamin E, carotenoids and selenium. Hundreds of other plant chemicals can play an antioxidant role and may help to prevent or repair cellular damage.

Q: How can a person get enough but not excessive antioxidants?

A: Since antioxidants work in conjunction with each other and with cellular enzyme systems in the body, it is best to have a balanced intake of a wide variety of antioxidants rather than very high doses of one or two.

The safest way to do this is by including plenty of fruits and vegetables in the diet, along with a moderate intake of whole grains and nuts. Generally, the brighter the fruit and vegetable color, the greater the concentration of naturally occurring antioxidants. As the local chapter of the American Cancer Society says, "Eat a rainbow."

If you take dietary supplements, it is likely safest to use a multiple vitamin and mineral product with moderate levels of each nutrient. Some is good, but more is not always better.


Alan Titchenal, Ph.D., C.N.S. and Joannie Dobbs, Ph.D., C.N.S.
are nutritionists in the Department of Human Nutrition, Food and Animal Sciences,
College of Tropical Agriculture and Human Resources, UH-Manoa.
Dr. Dobbs also works with the University Health Service

© 2005 Honolulu Star-Bulletin -- http://starbulletin.com
http://www.nutritionatc.hawaii.edu/HO/2005/302.htm

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Human Nutrition, Food & Animal Sciences · University of Hawai`i at Mānoa
1955 East-West Road · Honolulu, HI 96822
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