Women who drink moderate amounts of beer have lower risk of developing rheumatoid arthritis, a new study found.

The study was conducted by a team led by Bing Lu, MD, at the Division of Rheumatology, Immunology and Allergy at the Brigham and Women's Hospital and Harvard Medical School in Boston, Daily Rx reported.

Data for the study came from 238,131 participants enrolled in the Nurses Health Study and Nurses Health Study II.

Rheumatoid arthritis is a long-term disease that leads to inflammation in joints and surrounding tissues. The disease causes moderate to severe pain. The causes of the disease are unknown, according to PubMed Health.

Drinking high amounts of alcohol is bad for health. But, research has shown that low to moderate amounts of alcohol have several health benefits. Beer is rich in nutrients like carbohydrates, amino acids, minerals, vitamins and polyphenols. Hops are the main source of phenolic acids in beer. Polyphenols make drinks like beer and wine healthier than spirits.

The women in the studies provided information about their lifestyle and the amount of alcohol they consumed. Researchers divided the women into three categories- high, moderate and low- depending alcohol consumption. In the study, moderate alcohol intake was described as 5.0 to 9.9 grams/day of alcohol, Daily Rx reported.

Researchers then obtained medical records of the women and found that 908 women had developed rheumatoid arthritis during the study period.

Data analysis showed that women with moderate levels of alcohol intake had a 22 percent lower risk of rheumatoid arthritis than women who never drank alcohol. Also, women who drank two to four servings of beer per week had a 31 percent reduction in RA risk.

Researchers couldn't explain how alcohol consumption lowered RA risk.

In rheumatoid arthritis, the body's immune system starts attacking the body's tissues. According to James Maxwell, a rheumatologist at Rotherham Hospital, who conducted a similar research on alcohol and RA, alcohol suppresses the immune system.

"Alcohol reduces immune activity, at least to some extent, and [we] suspect that this is the main reason that alcohol consumption is associated with a reduction in severity of rheumatoid arthritis,"  Maxwell told CNN in an earlier interview. "Alcohol may also have a mild painkilling effect."

The National Health Institute supported the study and it is published in the journal Arthritis and Rheumatism.