Summary: Children who spend time playing outside in the sunshine have a 20% decreased risk of developing inflammatory bowel disease.
Source: Australian National University
Children who spend half an hour a day outside in the sun reduce their risk of inflammatory bowel disease (IBD), according to new research from The Australian National University (ANU).
More than 800,000 people live with the two life-long disorders which make up IBD – Crohn’s Disease and ulcerative colitis.
The paediatric study was based in Melbourne and led by Professor Robyn Lucas, from the ANU College of Health and Medicine.
“Taking children to play outside in the sun could be life-changing,” Professor Lucas said.
“It doesn’t have to be all at the same time. But, we found children who were outside and exposed to the sun for an extra half hour a day in total, had a lower risk of developing IBD by almost 20 per cent.”
The researchers found even short periods of sun exposure were associated with lower risk of children developing IBD.
“We found every 10 minutes of sun exposure was associated with a lower risk of developing inflammatory bowel disease by six per cent,” Professor Lucas said.
“At this stage what we have shown is there is a link between lack of sun exposure and increased risk of IBD.
“We already know that sunshine affects the immune system in ways that could decrease IBD – but we don’t know the exact pathways.
“But our research suggests that getting outside and into the sunshine is a good thing when it comes to preventing this terrible disease.”
Research shows Australia has one of the highest rates of inflammatory bowel disease.
“IBD is becoming more common and children are getting it at younger ages,” said Professor Lucas.
“The symptoms can be awful. If you have IBD you get intermittent diarrhoea, abdominal pain, inflammation and you can feel very unwell.
“Crohn’s and ulcerative colitis are horrible diseases where the autoimmune system has gone haywire and attacks the gut.”
Dr Lucas says it is still important Australians remained ‘sun smart’ and protect themselves and their children from any potential harmful effects from the sun.
“Everyone needs a bit of sun exposure every day or at least most days of the week. But we are not talking about sunbaking or getting sunburnt,” she said.
Higher Sun Exposure is Associated With Lower Risk of Pediatric Inflammatory Bowel Disease: A Matched Case-Control Study
Objectives: The incidence of pediatric inflammatory bowel disease (IBD) is increasing worldwide. Ecological studies show higher incidence in regions at higher latitude or lower ambient ultraviolet radiation; individual-level associations with sun exposure have not been assessed.
Methods: We recruited children (0–17 years) with IBD from two large hospitals in Melbourne, Australia. Control participants were recruited from the day surgery unit of one of the same hospitals. Questionnaires provided data on demographics, past sun exposure, the likelihood of sunburn (skin sensitivity) or tanning following sun exposure, use of sun protection, physical activity, and parental smoking and education. Grandparent ancestry was used to determine participant ethnicity. Cases and controls were matched on age and sex. We used conditional logistic regression to test the association between being an IBD case and past sun exposure at different ages, adjusted for a range of other factors.
Results: After matching, n = 99 cases and n = 396 controls were included in the analysis. In multivariable analysis, for each 10 min increment in leisure-time sun exposure in summer or winter there was a linear 6% reduction in the odds of having IBD (p = 0.002). Results were similar in sensitivity analyses including only the most recently diagnosed cases, only Caucasian cases and controls, only those with symptom onset within the year prior to study entry, or additionally adjusted for age or physical activity.
Discussion: Higher sun exposure in the previous summer or winter was associated with a reduced risk of having IBD. There are plausible pathways that could mediate this effect.