FRIDAY, June 11, 2004 (HealthDayNews) -- An apple, orange and a few carrots a day may keep rheumatoid arthritis away.
British researchers report that people with a high daily intake of vitamin C from fruits and vegetables are three times less likely to develop the painful joint illness than those with less healthy diets.
The findings "support current recommendations for eating five or more pieces of fresh fruit and vegetables a day," said study co-author Dorothy Pattison, an arthritis researcher at the University of Manchester, England.
Her team published its findings in the June issue of the Annals of the Rheumatic Diseases.
About 2.1 million Americans suffer from rheumatoid arthritis, an inflammation of the lining of the joints caused by dysfunction in the body's immune system. Rheumatoid arthritis is distinct from osteoarthritis, a much more common condition of unknown origin, characterized by a gradual deterioration of bones and joints.
In the Manchester study, Pattison and her colleagues compared the diets of 73 middle-aged or elderly rheumatoid arthritis patients to those of 146 individuals without the disease.
Study participants with the lowest levels of daily fruit and vegetable intake were at double the risk of developing rheumatoid arthritis, compared to people with the highest intake of these nutrient-packed foods, the researchers found.
The results were even more striking it came to vitamin C: Individuals with low daily levels of vitamin C were three times more likely to develop joint inflammation compared to those with the highest daily intake, the researchers said.
According to Pattison, levels of daily vitamin C deemed sufficient to protect against rheumatoid arthritis are easily obtained within current U.S. "five-a-day" dietary guidelines. In fact, "this amount of a variety of fruits and vegetables will provide an intake of vitamin C above that found to be protective in this study," she said.
At first glance, the new findings may seem at odds with the results of another, similar study released just last week. That study, conducted by researchers at Duke University, found that excessively high levels of vitamin C might encourage the development of osteoarthritis.
But Dr. John H. Klippel, president of the Arthritis Foundation, said the two studies may not be so far apart.
"First of all," he said, "we have to remember that these are two different disease processes." According to Klippel, vitamin C may be especially effective in preventing rheumatoid arthritis because it's a powerful antioxidant, fighting molecules that trigger rheumatoid inflammation.
Pattison agreed, noting that vitamin C "also has a critical role as a cofactor in collagen synthesis, the main protein found in [joint] tissue and bone, critical for bone and joint health."
Vitamin C may fight rheumatoid disease in a third way. According to Pattison, infection can trigger flare-ups of the rheumatoid immune response, and vitamin C's "integral role in fighting infection" may work to keep infection-linked inflammation at bay.
Finally, Klippel pointed out that both studies stress moderation in vitamin C intake as the best route to healthy bones and joints.
"It's excessive amounts of intake that seems to be the problem in osteoarthritis," he said.
For her part, Pattison stressed the British study only looked at dietary sources of vitamin C "and do not support the use of supplemental vitamin C to prevent rheumatoid arthritis."
More information
For more on the connections between diet and arthritis, visit the Arthritis Foundation.
