Enjoy that coffee: it may be good for you.
The National Institute of Neurological Diseases and Stroke (NINDS) describes multiple sclerosis (MS) as "an unpredictable disease of the central nervous system," symptoms of which can range from fairly benign to devastating. MS disrupts communication between the brain and the rest of the body.
Coffee contains over 1,000 biologically active compounds, including the central nervous system (CNS) stimulant, caffeine. Caffeine's neuroprotective properties can suppress the production of chemicals involved in the inflammatory response.
Previous studies have associated a high coffee intake with lower rates of cardiovascular disease (CVD), stroke and type 2 diabetes. In animal models of Alzheimer's disease, caffeine has helped to protect against blood-brain barrier leakage.
Two representative population studies provided data for the current research.
Dr. Anna Hedström, of the Institute of Environmental Medicine, Karolinska Institutet in Stockholm, Sweden, and colleagues compared 1,620 Swedish adults with MS with 2,788 healthy subjects, matched for age and sex.
In the US, teams from Johns Hopkins University in Baltimore, MD, the University of California-Berkeley and the Kaiser Permanente Division of Research in Oakland, CA, compared 1,159 people with MS with 1,172 healthy participants.
Six cups a day linked to 31% lower risk of MS
In both studies, participants provided information about their coffee drinking.
The Swedish participants quantified their usual daily intake in cups at different ages, from 15-19 years until they were 40 years and over.
In the US study, participants gave information about their maximum daily consumption. Those who drank one or more cups also recalled at what age they started drinking coffee regularly.
- Around 400,000 people live with MS in the US
- There are approximately 10,000 new diagnoses each year
- MS mostly affects white people, and women are more prone than men.
The researchers then estimated coffee consumption at and before the onset of symptoms in those with MS, and they compared the results with those of the healthy groups.
There was a consistently higher risk of MS among those who drank fewer cups of coffee every day in both studies, even after adjusting for factors such as smoking and weight during adolescence.
In the Swedish study, coffee consumption correlated with a lower risk of MS both at the onset of symptoms and 5-10 years beforehand. Those who consumed over six cups (900 ml+) daily had a 28-30% lower risk.
The US study revealed a 26-31% reduction in risk among those who drank above 948 ml daily at least 5 years before and at the start of symptoms, compared with those who never drank coffee.
Findings indicate that the more coffee people consume, the lower their risk of MS.
The authors caution that a causative link cannot be confirmed, since this was an observational study.
'Role of coffee warrants further investigation'
Limitations include the possibility that patients with MS changed their coffee consumption some time between receiving a diagnosis and giving the information, potentially influencing the results. Participants might also not have recalled their coffee consumption accurately.
The effects could also be due to another chemical component of coffee rather than caffeine. The team calls for further research.
Their findings support those of previous animal studies of MS, and they strengthen existing evidence that caffeine protects against neurodegenerative diseases such as Alzheimer's and Parkinson's disease.
In a linked editorial, Dr. Elaine Kingwell and Dr. José Maria Andreas Wijnands, of the Faculty of Medicine, University of British Columbia in Vancouver, Canada, point to inconsistencies in previous studies, but they express the hope that a better understanding of MS etiology may lead to novel MS therapies.
"Although it remains to be shown whether drinking coffee can prevent the development of MS, the results of these thorough analyses add to the growing evidence for the beneficial health effects of coffee. [...] The role of coffee in the development of MS clearly warrants further investigation, as do the mechanisms that underlie the relationship."
The researchers note that while the findings do not confirm that coffee drinking can prevent MS, they add to growing evidence that coffee may be good for health.
In January, Medical News Today reported on findings suggesting that stem cell transplantation might help people with MS.