The Ecological Relationship Between Food Access and Disease Activity in Canadian Children Newly Diagnosed With Juvenile Idiopathic Arthritis

Objective A healthy diet may contribute to improved disease activity in juvenile idiopathic arthritis (JIA). In Canada, access to healthy food is variable. This study examined the relationship between food accessibility, disease activity measures, and weight in children with JIA.

Methods Clinical data from children newly diagnosed with JIA (2017-2021) collected in the Canadian Alliance of Pediatric Rheumatology Investigators (CAPRI) Registry were linked to neighborhood-level food accessibility measures using postal codes. Data were analyzed at enrollment and at 1-year follow-up. Associations were assessed using Spearman rho correlations, Mann-Whitney U test (P < 0.05), and mixed-effects linear regression.

Results Among 641 patients with JIA, 21.9% were overweight or obese (BMI > 85th percentile) and lived in areas with less access to chain grocery stores (P = 0.02) compared with those with underweight or healthy BMI. At baseline, healthy-weight (P = 0.02) and overweight (P = 0.04) patients had lower disease activity (Clinical Juvenile Arthritis Disease Activity Score in 10 joints) than those with obesity; this association was not observed at 1-year follow-up. At baseline, a greater proportion of fast food restaurants in the neighborhood was linked to fewer active joints (r_s = −0.09, P = 0.04). At 1 year, higher densities of fast food restaurants and convenience stores were associated with lower disease activity (r_s = −0.14, P = 0.02).

Conclusion Obesity was linked to higher disease activity and reduced access to healthy food in chain grocery stores. However, greater access to both healthy and unhealthy food was associated with lower disease activity, possibly reflecting the general benefits of urban living.