Children with more green space near their homes have significantly stronger bones, a study has found, potentially leading to lifelong health benefits.
Scientists found that the children living in places with 20-25% more natural areas had increased bone strength that was equivalent to half a year’s natural growth.
The study, the first of its kind, also found that the risk of having very low bone density was about 65% lower for these children.
Bone strength grows in childhood and adolescence, before plateauing until about the age of 50 and then declining. Increasing the size and accessibility of green spaces for children could therefore prevent fractures and osteoporosis in older people, the researchers said.
The link between green spaces and stronger bones is likely to result from higher levels of physical activity in children who live near parks, as this spurs bone growth. The connection was strongest for green spaces with trees, which the scientists said may be because these were more attractive places to visit.
“The stronger the bone mass is during childhood, the more capacity you have for later in life,” said Prof Tim Nawrot, at Hasselt University in Belgium, who was part of the study team with Dr Hanne Sleurs and others. “So the real public health message from this study is that urban planners can make stronger bones of children, and that has long-lasting consequences.”
Previous research has found greater access to green spaces increases physical activity in children. Studies have also discovered multiple benefits for child development, including a lower risk of being overweight, lower blood pressure, higher IQs and better mental and emotional wellbeing.
Green spaces are also linked to better physical and mental health in adults. Woodland walks are estimated to save £185m a year in mental health costs in the UK.
The study, published in the journal JAMA Network Open, followed more than 300 children in a region of Flanders, Belgium, that included urban, suburban and rural areas.
Scientist used ultrasound to measure the bone density of the children at ages from four to six years old. The child’s age, weight, height, ethnicity and their mother’s level of education were taken into account.
The results showed, for example, that children with 25% more green space within 1,000 metres of their home had a 66% lower risk of having very low bone density, ie of being in the lowest 10% of measurements. No difference was found between the boys and the girls in the study.
The researchers said the results were important as low bone growth at a young age was as crucial to the onset of osteoporosis as bone loss through ageing.
Screen time, vitamin supplements and daily consumption of dairy products were also tested to see if they affected the children’s results but no significant impacts were found.
The study showed a strong association between nearby green space and bone strength in children but was not set up to show a causal link. To do that, children would need to wear accelerometers to record their physical activity. “That would not be a very easy experiment to do,” Nawrot said.
Two recent studies on bone density in adults and green spaces produced conflicting results. An analysis of 66,000 people in south-west China found a significant positive link. But research on 4,000 people aged 65 and older in Hong Kong did not find a convincing association, possibly because Hong Kong is a very densely populated city with little green space.
