For the study, researchers looked at a Swedish study of 1,629 people with MS and 2,807 healthy people, and a U.S. study of 1,159 people with MS and 1,172 healthy people. The studies characterized coffee consumption among persons with MS one and five years before MS symptoms began (as well as 10 years before MS symptoms began in the Swedish study) and compared it to coffee consumption of people who did not have MS at similar time periods.
The study also accounted for other factors such as age, sex, smoking, body mass index, and sun exposure habits.
Credit: Andy Ciordia, CC BY-NC-ND
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. Drinking large amounts of coffee five or 10 years before symptoms started was similarly protective. In the US study, 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 the disease.
"Caffeine intake has been associated with a reduced risk of Parkinson's and Alzheimer's diseases, and our study shows that coffee intake may also protect against MS, supporting the idea that the drug may have protective effects for the brain," said study author Ellen Mowry, MD, MCR, with Johns Hopkins University School of Medicine in Baltimore. "Caffeine should be studied for its impact on relapses and long-term disability in MS as well."
The study was supported by the Swedish Medical Research Council, the Swedish Research Council for Health, Working Life and Welfare, the Knut and Alice Wallenberg, AFA, and Swedish Brain Foundations, the Swedish Association for Persons with Neurological Disabilities and the U.S. National Institute of Neurological Disorders and Stroke, the National Institute of Environmental Health Sciences and the National Institute on Aging. Results will also be discussed at the American Academy of Neurology's 67th Annual Meeting in Washington, DC, April 18 to 25, 2015.