Caution about E > Endeavors, Spring 2000

A common form of Vitamin E has been associated with arthritis.

Newsmakers:
Caution about E
by Jill Aitoro

For all those health-conscious people who have made popping a vitamin as essential as brushing their teeth, results of a study may inspire a quick glance at the bottle label. Recent findings indicate that a component of vitamin E—gamma tocopherol—may somehow contribute to the degenerative disease osteoarthritis. Tocopherols are fat-soluble substances in the blood collectively known as vitamin E. To stamp out the possibility of harmful effects of gamma tocopherol, it must be ingested in proper proportion with the sister vitamin E component alpha tocopherol.

An earlier study looking at alpha, similar to gamma though different in antioxidant strength, had shown that people at the higher end of dietary intake of vitamin E might be protected from knee osteoarthritis worsening. The more recent study elaborates on that finding.

“No previous studies have looked at actual blood levels of these tocopherols but relied instead on what people reported eating, which is much less reliable,” says Joanne Jordan, research associate professor of medicine as well as the principal investigator of the government-sponsored Johnston County Osteoarthritis Project.

The most recent study looked at the blood of 200 random cases of people who had knee X-ray evidence of arthritis, as well as 200 random cases of people who did not. The study’s findings indicated that those with high measures of gamma tocopherol had increased chances of developing osteoarthritis, while alpha tocopherol neither protected against nor increased the risk of the disease.

“Looking at the ratio of alpha over gamma in the blood provided more information,” says Jordan, who is also a member of the Thurston Arthritis Research Center in the School of Medicine. “Those with a high ratio were 50 percent less likely to have osteoarthritis, which suggests that having more alpha is important,” she says.

The analysis was done cross-sectionally, meaning the various tests were conducted at the same time. While future studies extending from the findings will again use the initial study population, a long-term study will be needed.

“The findings clearly need to be corroborated in other studies that look to see whether or not the ratio (of alpha to gamma) at baseline predicts what the osteoarthritis status is going to be five or six years down the pike,” Jordan says.

This study was unique because half of the subjects were African American, and half were Caucasian. Jordan says the findings suggest that the increased risk with the gamma seemed to be particularly the case with the African American population.

“A high alpha over gamma ratio seemed more protective in the African Americans, which may be caused by the fact that they don’t have as much alpha in their blood as Caucasians,” Jordan says.

So what does all this mean for vitamin devotees? “If this turns out to be a finding that gets corroborated elsewhere, it may be wise at this juncture to just stick with the pure alpha tocopherol when taking a vitamin E supplement,” Jordan says. But no need just yet to cut the morning dose from the daily regimen.

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