Apparently rheumatoid arthritis currently affects around 1% adults in the UK, and previous studies have suggested that vitamin C and the pigment beta-cryptoxanthin, both of which are found in brightly-coloured fruit and vegetables, may act as antioxidants, and protect the body against the oxidative damage which can cause inflammation.
In this new research a team from Manchester, based in the Arthritis Research Campaign's Epidemiology Unit, collaborated with researchers from the Institute of Public Health at the University of Cambridge.
In the study they analysed health questionnaires and diet diaries of over 25000 45-74 year-olds which were completed as part of the EPIC (European Prospective Investigation of Cancer) Norfolk study of diet and chronic disease in the 1990s.
They then monitored the participants over a nine year period to identify new cases of inflammatory polyarthritis ( IP ), including rheumatoid arthritis.
According to Dr Dorothy Pattison, who led the research, they found that the average daily beta-cryptoxanthin intake of the 88 patients who had developed inflammatory polyarthritis was 40% lower than those who hadn't, and their intake of another carotenoid, zeaxanthin, was 20% lower.
It was found that those in the top third for beta-cryptoxanthin intake were only half as likely to develop IP as those in the lowest third.
Vitamin C also appeared to be an important factor.
These findings confirm previous research which suggests that a modest increase in fruit and vegetables containing beta-cryptoxanthin and vitamin C, equivalent to one glass of freshly-squeezed orange juice each day, might help to protect against developing inflammatory joint diseases.
In previously published research Dr Pattison has found that both low intakes of fruit and vegetables, particularly those high in vitamin C, and high levels of red meat consumption were associated with an increased risk of developing IP.
The full paper on the findings of the research appears in the August issue of The American Journal of Clinical Nutrition.
Information about weight, eating and exercise were collected during the survey. Participants were monitored for 24 hours on their food intake and also questioned about nine leisure-time physical activities (walking a mile or more at a time without stopping, jogging or running, bike riding, aerobic dancing or exercise, dancing, swimming, calisthenics, garden or yard work, and weight lifting). If individuals reported five or more moderate physical activities or three intensive activity sessions a week, it was considered healthy. Weight was considered within normal range if it fell within the body mass index (BMI) of 18.5 to 24.9 kg/m (obesity was considered at 25 kg/m ).
The researchers concluded that the healthy behaviors such as exercise and diet that lower the risks of diabetes also can lower the risk factors for periodontitis. Exercise--also known to reduce the C-reactive protein in the blood associated with inflammation in the heart and periodontal disease. Healthy eating habits, which builds the body's defenses against disease, also reduce the production of plaque biofilm, which is the primary epidemiological factor associated with periodontal disease.
Conquering periodontal disease, according to the researchers, may mean more than just targeting the disease but addressing multiple risk behaviors, too.
"Since oral health professionals may see their patients two or four times a year, it gives them several opportunities to promote these healthy behaviors," report the researchers.
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