Vitamin E Can Boost Immunity, Study Finds
One or two capsules of Vitamin E daily can at least partially reverse the decline in immunity that normally occurs during aging and thereby might make it easier for the elderly to fight off disease, a researcher from the U.S. Department of Agriculture said Thursday at a meeting of the American Chemical Society in Los Angeles.
Department of Agriculture nutritionist Simin N. Meydani fed one group of 17 volunteers a normal diet and a second group of 17 a diet supplemented by two capsules of Vitamin E daily. All those participating were over 60.
After one month on the diet, those receiving the vitamin showed a marked increase in immune responsiveness, as measured by standard skin tests of immune response and test tube measurements of white blood cell responses to foreign materials.
Meydani said she is not yet ready to make a blanket recommendation that all the elderly take daily supplements of Vitamin E, but she said that a growing body of epidemiological evidence in humans and laboratory studies in animals are pointing in that direction.
Immunologist Joel L. Schwartz of the Harvard University School of Dental Medicine in Boston agreed, noting that no previous study in humans had adequately documented the health and the diet of participants.
Immunologist Adrianne Bendich of Hoffmann-La Roche Inc. of Nutley, N.J., said Meydani’s study is “quite significant, mainly because it was so extremely well controlled. A growing body of evidence exists . . . that Vitamin E can delay the inevitable declines associated with aging.”
Schwartz and Bendich participated in a symposium on Vitamin E along with Meydani.
An increasing number of scientists believe that many, if not most, of the deleterious effects of aging arise from the interaction of body tissues with highly reactive forms of oxygen--the same oxidation process that causes the flesh of a freshly cut apple to turn brown or butter to turn rancid with time.
Cells of the immune system are among the most sensitive to oxidation in the body and are thus the first to be affected as the body’s normal repair processes begin to fail with age.
A few scientists even argue that it is precisely this breakdown of the immune system that causes most of the other ill effects of aging, Bendich noted. Others think that aging represents a general deterioration of all biochemical systems.
Vitamin E is an anti-oxidant. It tracks down the reactive form of oxygen and “defangs” it so that it can no longer cause damage. It can also stimulate the action of immune system components that are themselves anti-oxidants.
Meydani and others believe that the body does not get enough Vitamin E in a normal diet to efficiently combat oxidation. Among food sources of Vitamin E are plant oils (such as peanut oil and safflower oil), wheat germ and nuts.
The human studies grew out of Meydani’s previous research with mice.
“When we fed very old laboratory mice diets containing (10 to 15 times the normal amount) of Vitamin E, we found that their immune system was significantly more responsive and mounted a response closer to that of young mice than those fed standard levels,” she said. Similar results have also been reported by other researchers.
Prompted by that success, Meydani recruited 34 healthy volunteers over the age of 60 who moved into a dormitory at the Department of Agriculture’s Human Nutrition Research Center on Aging at Tufts University in Boston for 30 days.
Half of the volunteers received a normal diet containing about 15 international units of Vitamin E. The other half received the same diet but also took two capsules daily containing a total of 800 international units of Vitamin E. Neither the patients nor the researchers knew which volunteers received the Vitamin E.
Meydani and her colleagues measured the volunteers’ immune responsiveness at the beginning of the study and at the end of the 30 days. Although the analysis of the data is continuing because the test was just completed, the data indicates that the volunteers who received Vitamin E had a “significant increase” in immune responsiveness, she said.