When arthritis flairs up, grabbing a glass of wine with swollen fingers may be far from one's mind. But it may not be such a bad idea, according to research published in the Jan. 2 issue of the Proceedings of the National Academy of Sciences.
A team of researchers at Göteborg University in Sweden found that low and steady doses of alcohol slowed the onset of rheumatoid arthritis (RA) in laboratory mice. The discovery could prove to be useful in preventing the painful and destructive autoimmune disease in humans.
"Our aim here was to assess whether low but persistent consumption of ethanol in quantities nontoxic to the liver might affect the incidence of human RA," wrote the researchers, from the Department of Rheumatology and Inflammation Research and the Center for Bone Research. "Our results suggest that ethanol intake delays the onset and halts the progression of destructive arthritis."
The cause of arthritis is unknown, though theories abound, from family history to long-term knuckle cracking. With RA, the body's immune system turns on itself, confuses healthy tissue with foreign invaders and then attacks and inflames parts of the body. The destruction of joints may begin as soon as one year after onset.
The authors explained that since other studies have found a link between moderate drinking and lower rates of heart disease and stroke, they decided to test if alcohol may protect the health of joints and surrounding tissue by suppressing RA's autoimmune response.
The researchers used two groups of mice. The first group was given just water, while the other group was given a solution of 90 percent water and 10 percent ethanol, an amount similar to light to moderate consumption levels in humans. The mice were then given a collagen-type injection to induce arthritic symptoms.
After nine days, 85 percent of the control group showed arthritic symptoms, but only 20 percent of the mice that drank ethanol suffered the same problems.
Ethanol also appeared to reduce the severity of inflammation. By day 25, the arthritic mice in the ethanol group suffered flare-up symptoms only 5 percent of the time. The arthritic mice that drank only water experienced flare-ups 20 percent of the time. By day 35, those in the water-only group with arthritis were crippled, exhibiting symptoms 100 percent of the time. The ethanol group flared up only 40 percent of the time.
Further examination revealed that the mice who consumed ethanol had greater bone mineral density overall; studies on humans have similarly found that drinking wine and beer may contribute to greater bone mass. Also, the spleens of the mice in the ethanol group produced fewer inflammatory proteins that could contribute to the onset of arthritis. The authors did not observe side effects in the ethanol-consuming mice, which even maintained a healthy weight.
The researchers found that acetaldehyde, a metabolite of ethanol, may be responsible for the amelioration of joint inflammation, according to Nick Zagorski, a staff member at the PNAS journal. This shows promise, he said, for a therapy that may one day be alcohol-free and suitable for a wide range of patients. (The researchers noted that alcohol-based therapies are problematic because excessive consumption depresses the immune system and increases the chance of bacterial infections.)
A new approach would provide an alternative to current arthritis treatments, which vary from exercise in mild cases to corticosteroids in more severe instances. Many treatments have side effects; corticosteroids, for one, are believed to be related to higher blood pressure, bone thinning and weight gain. Doctors sometimes prescribe additional medications to combat those side effects.
More research is needed to better understand how moderate drinking helps prevent arthritis, the researchers noted. But they were impressed with how ethanol-consuming mice were better-equipped to deal with inflammation. "Even more importantly," they wrote, "the arthritis remained nondestructive even at late stages of the disease."
The researchers are confident that the benefits would be similar in humans, according to coauthor Andrej Tarkowski, even though some questions have yet to be answered. "It is presently unclear what dose would be the appropriate one," he said. "Maybe, speculatively, 1 to 2 glasses of wine per day, as in the case of cardiovascular diseases."