A regular moderate alcohol sample cuts the risk of developing rheumatoid arthritis by up to half, Swedish research suggests.
The Karolinska Institute assessed 2,750 people in two studies, Annals of the Rheumatic Diseases reports.
The risk was up to 50% lower for those who drank the equivalent of five glasses of wine a week compared with those who drank the least, they found.
However, arthritis experts warned that drinking too much alcohol increased the risk of a range of health problems.
Rheumatoid arthritis - an auto-immune disease caused by a malfunctioning immune system - is a condition which results in tender, stiff and swollen joints. It affects 400,000 people in the UK.
The two separate studies assessed environmental and genetic risk factors for rheumatoid arthritis.
Participants were quizzed about their lifestyle, including how much they smoked and drank, while blood samples were taken to check for genetic risk factors.
Researcher Dr Henrik Kallberg stressed the most important finding of the study was that smoking was a very significant risk factor for rheumatoid arthritis.
However, he added: "In addition, it is important to know that moderate alcohol consumption is not deleterious and may in some contexts be beneficial concerning risk for future onset of rheumatoid arthritis."
There are known to be links between moderate alcohol consumption and a reduced risk of other inflammatory processes, such as cardiovascular disease. However, the reason for this is still unclear.
Professor Robert Moots, from the Arthritis Research Campaign, said it was possible that drinking alcohol may have a protective effect against rheumatoid arthritis. But he said the study was not conclusive and any protective effect was not properly understood.
He said: "There is no doubt that drinking too much is very bad for our health in many ways and these risks by far outweigh any potential benefit for reducing the risk of rheumatoid arthritis, which this study points to, without being conclusive.
"We must also remember that drinking alcohol in excess can be especially dangerous in patients taking some anti-rheumatoid drugs that may cause liver damage.
"There are many modifiable lifestyle risk factors for developing rheumatoid arthritis and, as this study also points out, smoking is by far the greatest."