Drinking alcohol may cut the risk of developing rheumatoid arthritis (RA) and make symptoms less severe, research suggests.
People who never drink have around a fourfold greater risk of developing the condition as those who drink alcohol on 10 or more days a month, according to the study on more than 800 RA sufferers and 1,000 healthy people.
Among those who already have the condition, the progression of the disease is less severe if they drink, experts found.
The research, published online in the journal Rheumatology, was led by experts from the University of Sheffield.
People were asked to record the number of days on which they had at least one alcoholic drink over the previous month. This was categorised as no alcohol, drinking on one to five days, six to 10 days and more than 10 days.
The severity of symptoms in sufferers was tested by X-rays, blood tests and an examination of joints by a qualified health worker.
James Maxwell, a consultant rheumatologist at the Rotherham Foundation NHS Trust, said: "We found that patients who had drunk alcohol most frequently had symptoms that were less severe than those who had never drunk alcohol or only drunk it infrequently.
"X-rays showed there was less damage to joints, blood tests showed lower levels of inflammation, and there was less joint pain, swelling and disability. This is the first time that a dose-dependent inverse association between frequency of alcohol consumption and severity of RA has been shown in humans."
Dr Maxwell said the findings of non-drinkers being at greater risk of developing the condition matched previous studies. It is unclear why alcohol affects the chances or can make symptoms less severe.
"There is some evidence to show that alcohol suppresses the activity of the immune system, and that this may influence the pathways by which RA develops," he said.