Drinking a lot of coffee every day could potentially cut the risk of developing multiple sclerosis, according to findings that could help in the search for a cause to the illness.

Consuming more than 900ml – the equivalent of two Grande coffees in Starbucks – may offer up to a 30 per cent reduced risk of the condition, known as MS, experts found. Caffeine is known to have neuroprotective properties and has been shown to suppress inflammatory responses in the body.

Researchers from the Karolinska Institute in Stockholm, Johns Hopkins University in Maryland and the University of California, Berkeley, looked at two studies.

One in Sweden involved 1,620 adults with MS and a comparison group of 2,788 people without MS. The second was a US study of 1,159 people with MS and 1,172 healthy people.

In both studies, people were asked about their coffee consumption and how long they had been drinking coffee for. The researchers then estimated coffee intake at and before the start of MS symptoms in those who developed the disease, and compared this with healthy groups.

The results showed that the risk of MS was consistently higher among people who drank fewer cups of coffee every day in both studies, even after taking into account other factors that might influence the results.

In the Swedish study, drinking coffee was linked to a lower risk of MS both at the start of symptoms and five and 10 years beforehand. Among those who drank more than six small cups (more than 900ml) every day, there was a 28 per cent to 30 per cent lower risk compared with non-coffee drinkers.

Similar results were found in the US study, with a 26 per cent to 31 per cent lower risk among those drinking more than 948ml daily at least five years beforehand and at the start of symptoms.

The authors, writing in the Journal of Neurology, Neurosurgery & Psychiatry, stressed that theirs was an observational study, so no firm conclusions could be drawn about cause and effect.

But they concluded: “Lower odds of MS with increasing consumption of coffee were observed, regardless of whether coffee consumption at disease onset or five or 10 years prior to disease onset was considered. In accordance with studies in animal models of MS, high consumption of coffee may decrease the risk of developing MS.”

In an accompanying editorial, Elaine Kingwell and Jose Maria Andreas Wijnands, from the University of British Columbia in Vancouver, said “the results of these thorough analyses add to the growing evidence for the beneficial health effects of coffee”.