JAMA Vitamin E Study Results Overinterpreted and Misapplied
Consumers Should Continue to Use Vitamin E Supplements

WASHINGTON, D.C.,March 6, 2001—Findings from a vitamin E study published in this week’s Journal of the American Medical Association (JAMA) were overinterpreted and misapplied. The study conclusions were based on short-term markers of a biochemical process, not clinically significant disease markers.

The researchers did not measure disease markers, such as the build up of plaque in the arteries. "Clinical data indicate that vitamin E slows the thickening of the walls of the carotid arteries, a change directly associated with atherosclerosis and cardiovascular disease," stated John Hathcock, Ph.D., vice president of nutritional and regulatory science at the Council for Responsible Nutrition, "and support the regular use of vitamin E supplements."

As reported by Reuters Health (March 5), a three-year study–discussed at this week’s Annual Conference on Cardiovascular Disease Epidemiology and Prevention–found that high doses of vitamin E slowed the progression of atherosclerosis. The California researchers used ultrasound to measure the thickness of carotid arterial walls in 573 adults free of heart disease. The benefit was limited to vitamin E from supplements; no effect was observed with dietary vitamin E.

The JAMA study involved 30 healthy adults, aged 18-60 years, divided into six groups of five subjects, and randomly assigned to receive placebo or one of five doses of natural vitamin E–200, 400, 800, 1200 or 2000 international units (IU) per day for eight weeks. Urinary levels of three compounds were measured before the study began (at baseline), every two weeks during the study, and one, three and eight weeks after the study ended.

Vitamin E is an antioxidant and neutralizes free radicals, reducing oxidative stress. Therefore, vitamin E should reduce levels of substances that are produced from reactions with free radicals. The researchers found, however, that vitamin E did not affect the amount of these biochemical markers. One explanation for the lack of demonstrated effect on the markers measured in the JAMA study is that the participants were healthy and probably had sufficient levels of antioxidants to prevent oxidative stress.

Balz Frei, Ph.D., director of the Linus Pauling Institute at Oregon State University, explained, "In subjects who already have normal levels of oxidative stress, such as in the present study, no further reduction is possible. It still might be advisable to take vitamin E supplements as a safety precaution to prevent conditions of increased oxidative stress from developing." Oxidative stress is typically increased among smokers, diabetics, alcoholics, and those who suffer from heart disease and inflammatory disorders.

The Council for Responsible Nutrition (CRN) is a science-based, trade association founded in 1973 and represents more than 100 companies in the dietary supplement industry, including ingredient suppliers and manufacturers. CRN members adhere to a strong code of ethics, comply with dosage limits and manufacture dietary supplements to high quality standards under good manufacturing practices.