A high vitamin C intake may protect against the development of painful widespread rheumatoid arthritis, report researchers. The findings are based on 23,000 men and women taking part in the ongoing European Prospective Investigation of Cancer (EPIC). All were aged between 45 and 74 when they entered EPIC between 1993 and 1997.

As part of the EPIC study, their diets were assessed using seven day food intake diaries.

Patients who developed arthritis were matched with two people of the same age and gender, and their diets assessed. Those with inflammatory polyarthritis tended to have a lower daily intake of fruits and vegetables than those who did not develop the disease. People with a low intake of fruit and vegetables had around double the risk of developing arthritis of those with a high intake.

But vitamin C itself seemed to have an even more important role. Those with the lowest levels of vitamin C intake were three times more likely to develop inflammatory arthritis than those with the highest intakes, the results showed.

Significantly, the recommended daily intake of vitamin C is 40 mg a day. Those with levels below this were at four times the risk of inflammatory polyarthritis. But those who consumed less than 56 mg a day were still at three times the risk, suggesting the RDA for vitamin C may need to be reviewed. Previous research has shown that harmful free radicals have been found in the joint fluid of patients with rheumatoid arthritis and inflamed joint. Vitamin C is a powerful antioxidant that mops up free radicals.

British Medical Journal, Jun 9, 2004