In a study released today, researchers at Johns Hopkins School of Medicine have concluded that drinking four or more cups of coffee per day may reduce your odds of developing multiple sclerosis (MS).
Since caffeine has been associated with a reduced risk of Parkinson’s disease and Alzheimer’s, the team theorized the same might be true for other neurological disorders like MS.
The results of their study will be presented at the 67th annual meeting of the American Academy of Neurology in Washington, D.C., from April 18 to 25.
The team, led by Dr. Ellen Mowry, assistant professor of neurology at Johns Hopkins University, looked at two studies.
One was in Sweden, and the other was in the United States. Both charted coffee consumption among people living with MS as well as people without MS.
The Swedish study looked at 1,629 people with MS and 2,807 people without MS, while a similar study in the U.S. profiled 1,159 people with MS and 1,172 without MS.
Researchers wanted to know who was drinking coffee (and how much) 1 year and 5 years prior to being diagnosed with MS. The Swedish study also included data from 10 years before diagnosis.
The Swedish study concluded people who did not drink coffee were one and a half times more likely to develop MS than those who drank at least six cups of java per day.
In the U.S. study, those who abstained from coffee shared the same risk with their Swedish counterparts compared to coffee drinkers who downed at least four cups per day.
The discrepancy between the number of cups in Sweden and those in the U.S. is due to the size of the cups, Mowry told Healthline. She pointed out that “six cups in the Swedish study [equals] about the same as four cups in the U.S.”
"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 Mowry in a press release.
So how is coffee protecting the brain from all of these neurological disorders? Researchers are uncertain.
“Caffeine crosses the blood-brain barrier,” said Mowry, “If our results are true, the mechanisms by which caffeine may be impacting MS susceptibility need more careful investigation. Caffeine has been shown to potentially impact some of the immune cells that typically reside in the brain (microglia) but also may impact other aspects of immune function.”
So why coffee? Can other caffeinated beverages like black tea, for example, have the same effect?
“We attempted to explore this in the U.S. portion of the study and didn't see an apparent association of tea,” Mowry said, “but that doesn't mean a link doesn't exist. Further work taking into account that the caffeine content of tea differs from coffee should be done.”
If Mowry’s theory that caffeine could be influencing immune cells responsible for MS activity, could drinking coffee prevent relapses? Researchers don’t know yet.
“There may be toxicities associated with the ingestion of any medication or drug,” explained Mowry when asked if too much coffee might be bad for you. “There is not sufficient evidence from this study to support a recommendation to ingest caffeine/coffee. However, further work should be done to evaluate the possibility that coffee intake could impact MS, particularly surrounding mechanisms by which it may do so, which ultimately could lead to developing new therapies.”
In the future, Mowry said, “I hope to explore caffeine as well as other aspects of diet in order to better evaluate their link with MS risk and prognosis.”