Vitamin E targets dangerous inflammation

People with diabetes face a high risk of heart attack and stroke. One apparent culprit is the chronic, low-grade inflammation that they develop. Megadoses of vitamin E can dramatically reduce that inflammation, a new study finds.

Ishwarlal Jialal and Sridevi Devaraj of the University of Texas Southwestern Medical Center at Dallas studied 47 men and women with adult-onset, or type II, diabetes and 25 healthy volunteers. The scientists sampled people’s blood before and after each received 1,200 international units of vitamin E daily for 3 months.

Before treatment, the 23 people with major diabetes complications such as kidney failure produced roughly twice as much C-reactive protein (CRP), a marker of inflammation, as the healthy group did. Concentrations of CRP were about 33 percent higher in blood from the 24 people with mild diabetes than in the healthy volunteers.

Vitamin E supplements lowered CRP concentrations dramatically in all three groups. CRP measurements in people with mild disease fell to the healthy group’s starting concentration, and those in people with advanced diabetes fell to the concentrations detected in the other diabetic people before treatment.

More importantly, Jialal says, vitamin E cut production of a cytokine, an immune-system signaling molecule. In test-tube experiments, white blood cells were stimulated to provoke an immune response. Cells from volunteers after treatment responded by producing about one third as much interleukin-6—a cytokine that tells the liver to make CRP—as was generated by cells from blood drawn before people took vitamin E. Jialal and Devaraj present their data in the Oct. 23 Free Radical Biology and Medicine.

Their related study in the July 11 Circulation showed that compared with white blood cells from healthy people, those from people with diabetes secrete far more of three types of molecules that foster atherosclerosis. After vitamin supplementation, production of all three fell dramatically for each group.

These studies suggest that high doses of vitamin E might help fight heart disease in diabetics and others, including elderly and obese people (SN: 5/1/99, p. 278), who typically experience chronic inflammation, Jialal says. However, he adds, after supplementation, CRP in even the normal group remains at concentrations that have been linked to high risk of heart disease and stroke. Additional therapies or lifestyle improvements, therefore, appear warranted, he says.

If vitamin E supplementation dampens interleukin-6 production in circulating blood as it does in the test tube, it should reduce inflammation and atherosclerosis in coronary arteries, says biochemist Sushil Jain of Louisiana State University Health Sciences Center in Shreveport.

The new data also offer “further evidence that type II diabetes is a disease of the immune system,” says British diabetes specialist John C. Pickup of Guy’s Hospital in London. Five years ago, he says, “people would have said that was a ridiculous idea.”

Janet Raloff is the Editor, Digital of Science News Explores, a daily online magazine for middle school students. She started at Science News in 1977 as the environment and policy writer, specializing in toxicology. To her never-ending surprise, her daughter became a toxicologist.

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