Dietary intake and serum concentrations of antioxidants in children with juvenile arthritis

Earlier studies have shown that patients suffering from juvenile arthritis (JA) have reduced serum concentrations of antioxidants compared with healthy controls. The aim of this study was to investigate whether the lower serum concentration of antioxidants found in these patients could be explained by a low dietary intake.

Serum from 14 patients and 22 healthy controls was analysed for the antioxidants retinol, beta-carotene, vitamin E, zinc and selenium. All of the participants completed a food frequency questionnaire that gave a picture of their dietary intake for the previous month.

Compared with the healthy controls, the patients with JA had significantly reduced serum concentrations of beta-carotene (0.57 +/- 0.41 and 0.71 +/- 0.26 mmol/L respectively, p < 0.05), retinol (918 +/- 246 and 1176 +/- 300 IE/L, respectively, p < 0.01) and zinc (12.7 +/- 2.6 and 13.3 +/- 1.2 mmol/L, respectively, p < 0.05). The dietary intake was equivalent in the two groups, but the dietary intake of vitamin A, vitamin E and zinc did not reach the recommended dietary allowances. There was a statistically significant difference in serum concentrations of vitamin E and selenium between patients regularly taking a dietary supplements and patients who did not do so (p < 0.05). This difference was not found in the control group.

The results of this study confirm that children suffering from JCA have reduced serum levels of beta-carotene, retinol and zinc compared with healthy controls. Patients benefited from dietary supplements of nutrients when the dietary intake did not reach the recommended dietary allowances.