High vitamin C intake may protect against rheumatoid arthritis

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. They lived in Norfolk, UK.

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

Seventy three people developed inflammatory polyarthritis - two or more swollen joints for at least a month - between 1993 and 2001. They were referred by their family doctors to the Norfolk Arthritis Register.

Each of the patients with arthritis was 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.

There was some evidence that vitamin E and beta carotene also affected the risk of developing the disease, but these findings were nothing like as strong as the association with vitamin C intake.

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.

Click here to view the paper in full: http://press.psprings.co.uk/ard/july/843_ar16097.pdf