Drinking alcohol may help reduce the severity of rheumatoid arthritis and cut the risk of developing the painful and crippling disease, a study published Wednesday has shown for the first time.
Researchers led by Gerry Wilson, a professor at the University of Sheffield in Britain, asked 873 arthritis patients and a control group of 1,004 people how frequently they had consumed alcohol in the previous month.
The participants also completed a detailed questionnaire, were given X-rays and blood tests, and had their joints examined.
"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," said lead author James Maxwell, a rheumatologist at the Rotherham Foundation NHS Trust.
X-rays showed less damage to joints, and blood tests showed lower levels of inflammation, according to the report, published in the journal Rheumatology.
There was also less pain, swelling and disability.
Earlier studies had reported similar results in rodents, but this is the first to show that arthritis symptoms diminish in humans in proportion to the frequency of alcohol consumption.
The researchers found that non-drinkers were four times more likely to develop rheumatoid arthritis that people who drank alcohol on more than ten days a month.
They cautioned that any possible benefits from alcohol consumption in relation to rheumatism must be weighed against all the well-known health consequences of immoderate drinking.
The findings held equally true for women and men, and for two distinct forms of the disease, one called anti-cyclic citrullinated peptide (anti-CCP) and the other known simply as "negative".
"Anti-CCP antibodies are not present in most 'normal' people without arthritis," explained Maxwell.
Previous research has shown that these antibodies develop prior to the onset of rheumatoid arthritis, and are likely linked to the process which causes the disease.
Some patients don't develop anti-CCP antibodies, but the symptoms are much more severe in those that do.
The scientists could only speculate as to why alcohol helped reduce symptoms and risk.
"There is some evidence that alcohol suppresses the activity of the immune system, and that this may influence the pathways by which rheumatoid arthritis develops," Maxwell said.
Once the disease has developed, it is also possible that drinking may act as a pain killer, he added.
One limitation of the study is that it did not measure how much people drank, only the frequency. It also relies on people's memories, and does not report long-term drinking habits.
Rheumatoid arthritis affects about one percent of people in the United States and Europe, mainly in older populations. Incidence appears to be somewhat lower in Asia, suggesting that genetics may play a role.
Exactly what causes the disease remains a mystery, and there is no known cure.