Two population based studies published recently seem to suggest just that.
The studies compared coffee intake before the diagnosis of Multiple Sclerosis (MS) in a sample of MS patients versus healthy people (controls). They adjusted for several other factors that could confuse the results, including age, sex, smoking history, weight (body mass index), and sun exposure habits (vitamin D has been suggested to be associated with a reduced risk of MS).
The Swedish study looked at 1629 people with MS and 2807 healthy people, and the US cohort (Northern California) included 1159 people with MS and 1172 healthy people.
In the Swedish study, consuming at least 6 cups of coffee daily prior reduced the likelihood of having MS to 2/3 (0.67) (though the 95% confidence interval [CI] was 0.47 – 0.95 – meaning the true number could be between a 5% and a 53% reduction).
Similarly, in the US patients, people who consumed four or more cups of coffee daily also had a similarly reduced likelihood of MS (OR, 0.67; 95% CI, 0.47 – 0.95).
The two studies matching each other is encouraging that this could be a real effect, but these comparative studies are notorious for giving false leads – when we study medications or supplements against placebo (a sugar pill) without knowing who is taking what (blinded) and the medication or supplement being used by any patient is chosen by chance (randomised), these things often are shown to not be true.
The results are to be presented at the 67th American Academy of Neurology (AAN) Annual Meeting, April 18-25, 2015.
Photo credit: Nina Matthews Photography (Creative Commons).