2004-05-18
By Diane Clay
The Oklahoman

One of the hottest fields in preventative research is the study of nutrients and how much is needed to get the best results.

Researchers at the Oklahoma Medical Research Foundation found themselves in the middle of the debate during work on free radicals and antioxidants.

They noticed that when they used high levels of alpha- tocopherol, commonly known as vitamin E, to fight free radicals, another beneficial nutrient was being kicked out.

That nutrient, gamma-tocopherol, is a healthy component found in green leafy vegetables along with vitamin E. Both components are needed for a healthy diet. Gamma-tocopherol has been shown to be beneficial in preventing prostate cancer.

Researchers at the Oklahoma foundation also believe gamma-tocopherol is involved in neuro-degenerative diseases such as amyotrophic lateral sclerosis (ALS) and possibly has a beneficial effect on heart problems.

"What has been shown is that dietary vitamin E is very beneficial in lowering heart problems, some cancers, etc. But when you start putting in large amounts of the supplement, that does not hold true," said Robert Floyd, head of the foundation's Free Radical Biology and Aging Research Program.

"If you look very carefully over the papers that have been published, gamma-tocopherol is very important and may be even more important than alpha-tocopherol."

Floyd, Kenneth Hensley and other researchers are working with vitamin E to determine its benefits in ridding the body of unneeded and dangerous components called free radicals.

Floyd said vitamin E is best consumed through food, but supplements are OK. He said the typical amount of vitamin E in multivitamins, somewhere near 100 International Units, is fine. Doses that reach 800 IU or 1,000 IU become dangerous.

"I don't want people to just quit taking vitamin E. It's just the really high levels that are of a concern," he said.

Floyd said work also is being done elsewhere on possible negative effects of consuming too much beta-carotene, which is found in orange and yellow vegetables and fruits. He said it doesn't appear high levels of vitamin C produce the same problem.

Floyd and other researchers are working to understand this process at the molecular level to determine why gamma-tocopherol is lost and why the component protects against some diseases.

"That's the hottest thing that is going on in the antioxidant world at the present time," Floyd said.

"You are beginning to see people question this on a worldwide scene."

Vitamins

Vitamin A: Can be found in foods including eggs, whole milk, liver, fortified milk, fortified cereal and dark fruits and vegetables.

Vitamin B-1 (thiamin): Can be found in baked potatoes, ham, whole grain flour, oranges, peas, raisins and brown rice.

Vitamin B-9 (folic acid): Can be found in asparagus, avocados, bananas, beans, Brussels sprouts, cantaloupe, citrus fruits/ juices and green leafy vegetables.

Vitamin C: Can be found in fruits, orange juice, vegetables and rose hips.

Vitamin D: Can be found in cod-liver oil, egg substitutes, herring, salmon, sardines, tuna, sunlight and vitamin D-fortified milk.

Vitamin E: Can be found in almonds, asparagus, avocados, broccoli, corn, canola oil, fortified cereals, several kinds of nuts and wheat germ.

Vitamin P: Can be found in apricots, broccoli, buckwheat, cherries, grapes, green peppers, green tea, onions, red wine and tomatoes.