High daily coffee consumption may lower risk of multiple sclerosis
Drinking around six cups of coffee – more than 900 ml – every day is linked to a reduced risk of multiple sclerosis (MS), according to a new study lead from the Institute of Environmental Medicine at Karolinska Institutet. The findings are being published online in the Journal of Neurology Neurosurgery & Psychiatry.
Caffeine, a central nervous system stimulant, has neuroprotective properties and can suppress the production of chemicals involved in the inflammatory response, which may explain the association found, suggest the researchers behind the current study. They base their findings on two representative population studies: one in Sweden comprising 1620 adults with MS and a comparison group of 2788, matched for age and sex; and a US study comprising 1159 people with MS and 1172 healthy people. In both studies, participants were quizzed about their coffee drinking.
The results showed that the risk of MS was consistently higher among those drinking fewer cups of coffee every day in both studies, even after taking account of potentially important influential factors, such as smoking, and weight during the teenage years.
In the Swedish study, coffee consumption was associated with a reduced risk of MS both at the start of symptoms and 5 and 10 years beforehand, with a 28-30% lower risk among those drinking more than six cups (900 ml+) every day. Similar results were found in the US study, with a 26-31% lower risk among those drinking more than 948 ml daily at least five years beforehand and at the start of symptoms compared with those who never drank coffee.
An observational study
The higher the quantity of coffee drunk, the lower the risk of MS, the results showed. However, the researchers point out that this is an observational study, so no firm conclusions can be drawn about cause and effect. Changes in coffee consumption between an MS diagnosis and data collection as well as inaccurate recall of coffee consumption could have influenced the results.
There are previous animal studies of MS and coffee to back up the current results, but the researchers do not rule out that there could be other chemical components of coffee than the caffeine that may be responsible for the beneficial effect.
The study was led by Anna Hedström and Lars Alfredsson at the Institute of Environmental Medicine, and supported by grants from the Swedish Research Council; the Swedish Research Council for Health, Working Life and Welfare, Knut and Alice Wallenberg foundation, the AFA foundation, the Swedish Brain foundation, the Swedish Association for Persons with Neurological Disabilities.This news article is an edited version of a press release from BMJ Publishing.
High consumption of coffee is associated with decreased multiple sclerosis risk: results from two independent studies
A K Hedström, E M Mowry, M A Gianfrancesco, X Shao, C A Schaefer, L Shen,T Olsson, L F Barcellos, L Alfredsson
Journal of Neurology Neurosurgery & Psychiatry, online 3 March 2016, doi: 10.1136/jnnp-2015-312176