Washington (AFP) - People who drink four to six cups of coffee daily may be less likely to get multiple sclerosis, according to international research out Thursday.

"Caffeine intake has been associated with a reduced risk of Parkinson's and Alzheimer's diseases," said lead author Ellen Mowry of the Johns Hopkins University School of Medicine in Baltimore, Maryland.

"Our study shows that coffee intake may also protect against MS, supporting the idea that the drug may have protective effects for the brain," she added.

The findings of a US and Swedish study -- released ahead of the American Academy of Neurology annual meeting in Washington -- each compared more than 1,000 MS patients to a similar number of healthy people.

Researchers tracked how much coffee the subjects drank in the one, five and 10 years before symptoms began for those afflicted with MS.

After accounting for other factors such as age, sex, smoking, body mass index and sun exposure, the Swedish study found that "compared to people who drank at least six cups of coffee per day during the year before symptoms appeared, those who did not drink coffee had about a one and a half times increased risk of developing MS."

Similar protective effects were seen among those who drank lots of coffee five to 10 years before symptoms appeared.

The US study found that "people who didn't drink coffee were also about one and a half times more likely to develop the disease than those who drank four or more cups of coffee per day in the year before symptoms started to develop."

More research is needed to determine if caffeine in coffee has any impact on relapse or long-term disability due to MS, an incurable disease of the central nervous system that affects 2.3 million people worldwide.

The study was funded by the Swedish Medical Research Council, the US National Institute of Neurological Disorders and Stroke, the National Institute of Environmental Health Sciences and the National Institute on Aging.