Greenspace exposure during childhood reduces risk for IBD
Childhood exposure to residential greenspace was associated with a reduced risk for inflammatory bowel disease, according to data published in the American Journal of Gastroenterology.
“Intervention studies designed to target specific environmental risk factors to reduce the risk of IBD should include greenspace in study design,” Michael Elten, MSc, from the School of Epidemiology and Public Health, University of Ottawa in Canada, and colleagues wrote. “It is possible that by changing our immediate environment, we could prevent childhood-onset IBD.”
Elten and colleagues performed a retrospective cohort study using linked population-based health administrative environmental data sets and identified 2,715,318 mother-infant pairs. Using normalized difference vegetation index derived from remote-sensing methods, investigators measured exposure to residential greenspace. For pregnancy and childhood periods, the average greenspace was estimated.
“We used mixed effects Cox proportional hazard models to assess potential associations between residential greenspace and the risk of developing IBD before 18 years while adjusting for covariates including sex, maternal IBD, rural/urban residence at birth, and neighborhood income,” the researchers wrote.
During follow-up, 3,444 IBD diagnoses occurred.
“An increase in the interquartile range of residential greenspace during the childhood period was associated with a lower risk of developing pediatric-onset IBD (hazard ratio [HR] = 0.77; 95% CI 0.74–0.81),” Elten and colleagues wrote.
Results demonstrated this correlation was significant for ulcerative colitis (HR = 0.72; 95% CI 0.67–0.78) and Crohn’s disease (HR = 0.81; 95% CI 0.76–0.87). Across increasing quartiles of greenspace, investigators noted a linear dose response (P < .0001).
Investigators noted there was no consistent correlation observed between maternal intrapartum greenspace exposure and pediatric onset-IBD.
“Greenspace is an emerging area in environmental health research, and this study is the first to investigate and report its protective effect with IBD,” the researchers concluded. “Future studies should look at using alternative measures to [normalized difference vegetation index] to evaluate the specific features of greenspace responsible for this finding (such as type or access to vegetation) and look for effects on the gut microbiome, immune dysregulation, and genetic predisposition in IBD.”