Q. I have read many times about the importance of vitamin E as an antioxidant. However, vitamin E comes in many different forms.Which type do you recommend and why?
--J.N., West Palm Beach, Fla.
A.Antioxidants protect key cell components by neutralizing the damaging effects of "free radicals," which are natural by-products of cell metabolism. Free radicals form when oxygen is "metabolized," or burned by the body.
The cellular damage caused by free radicals is believed to contribute to a variety of health problems.
Vitamins, which are nutritionally essential to control metabolic processes, usually are classified by their solubility in the body and are either "water soluble" or "fat soluble."
Most of the water-soluble vitamins are not normally stored in the body in appreciable amounts and are excreted in the urine. Thus, a daily supply in the body helps to avoid depletion and interruption of normal physiological functions.
Each of the fat-soluble vitamins A, D, E and K has a distinct role. Several have antioxidant properties to depress the effects of free radicals. Vitamin E is one of the most important antioxidants because it is "lipid soluble," which means that it works in the fatty compartments of the body and protects cell membranes from turning rancid.
Vitamin E helps prevent plaque buildup in arteries and promotes their flexibility. It helps slow the onset of Alzheimer's disease, prevents coronary-artery disease, and can reduce ischemic strokes (caused by plaque in a brain artery) by more than half. In a recent study of Alzheimer's patients, vitamin E delayed progression of the disease in more than half of those who took it.
Vitamin E comes in eight different forms, however, a puzzling fact if you're trying to choose one type to take. Four types are classified as tocopherols and four as tocotrienols.
Most vitamin E products are d-alpha tocopherol, a natural form of the vitamin. Some are dl-alpha tocopherol, which is synthetic and not nearly as effective an antioxidant as natural vitamin E.
It is best to get as many of the tocopherols and tocotrienols as possible. I personally take a supplement of mixed tocopherols and tocotrienols.
I recommend taking at least 400 IUs (International Units) of vitamin E per day, but I usually take 800 to 1,200 IUs daily. If, however, you are taking blood thinners, such as Coumadin or aspirin, limit vitamin E intake to 400 IUs per day.
Q.Do nutritional supplements improve memory? --A.H., Norfolk, Va.
A.Many nutritional supplements help improve memory, but two appear to be especially effective: ginkgo and phosphatidyl serine. Ginkgo increases circulation to the brain, which sends the brain more oxygen.
A 1997 study in the Journal of the American Medical Association revealed that 30 percent of patients with dementia performed better on memory and reasoning tests after taking ginkgo for a year than those who took the placebo.
A dose of 120 mg (milligrams) of gingko a day usually is quite effective. Please note that memory improves in only about half of those who take ginkgo.
If your memory doesn't improve after taking it for a month, double the dosage to 240 mg for another month. If it hasn't improved after the second month, discontinue using it.
Phosphatidyl serine is a soy-based nutritional supplement that, according to Thomas Crook, renowned research psychologist and author of The Memory Cure, is the best supplement he has found for improving memory.
Crook believes that taking phosphatidyl serine can roll back the clock 14 years for recalling names, 12 years for written information and seven years for recognizing someone previously seen.
Phosphatidyl serine is expensive--about $15-$30 for 30 capsules or about $40 or more for 60 capsules of 100 mg each. I usually start my patients with 100 mg per day.
It is available at most health-food stores.