Caffeine appears to help ward off multiple sclerosis, at least in a preliminary animal study. Mice given caffeine were 75 percent less likely to develop the animal model of MS than those not given it, said study senior author Dr. Margaret Bynoe, an assistant professor of microbiology and immunology at Cornell University School of Veterinary Medicine, in Ithaca, N.Y.

"The 25 percent who got it got mild cases," she said, although she noted the research is preliminary and the trials were in mice that had the animal model of MS.

Caffeine is known to block a compound called adenosine. "Inhibiting adenosine prevents the infiltration of lymphocytes [a type of white blood cell involved in immune system response] into the central nervous system," Bynoe explained. "If the lymphocytes cannot get in, you cannot get the inflammation characteristic of MS. The inflammatory response is what causes the damage to the myelin covering the nerve cells."

Bynoe believes her team is the first to demonstrate this mechanism.

In the animals given caffeine, the equivalent of 6 to 8 cups of coffee a day for humans, "there was a reduction in the inflammation, the pathology, a reduction in the brain pathology," Bynoe said.

Adenosine plays a crucial role in many body processes, including energy transfer, the promotion of sleep and the suppression of arousal. On the cellular level, caffeine can bind to the same receptors as adenosine, preventing the adenosine from attaching to cells in the central nervous system.

The new finding is "certainly deserving of further study," said Dr. John Richert, executive vice president of research and clinical programs for the National Multiple Sclerosis Society.

But he had a caveat: "It's important to note that EAE [the animal model of MS] is not MS, and many potential treatments that have worked on EAE have not worked on MS."

About MS 

MS is a debilitating autoimmune disease, and about 400,000 Americans are affected, according to the National Multiple Sclerosis Society. In MS, the immune system attacks the myelin, the fatty sheath that protects the nerve fibers in the central nervous system.

The myelin, as it is damaged, forms scar tissue that prevents or hinders nerve impulses from getting through, leading to a variety of symptoms such as numbness in the limbs or loss of vision. Treatments include medications, physical therapy and the use of assistive devices.

SOURCES: Margaret Bynoe, Ph.D., assistant professor, microbiology and immunology, Cornell University School of Veterinary Medicine, Ithaca, N.Y.; John Richert, M.D., executive vice president, research and clinical programs, National Multiple Sclerosis Society, New York City, Tom Gasiewicz, Ph.D., professor and chairman, department of environmental medicine, University of Rochester Medical Center, Rochester, N.Y.; Joshua Bomser, Ph.D., associate professor, nutrition, Ohio State University, Columbus; April 6-7, 2008, presentations, Experimental Biology annual meeting, San Diego