Children living in urban areas with high levels of air pollution, noise and traffic may be at higher risk of childhood obesity, according to a new study.
Researchers from the Barcelona Institute for Global Health and the University Institute for Primary Care Research Jordi Gol analysed data on more than 2,200 children aged between 9 and 12 years in the Spanish city of Sabadell, 40 per cent of which were overweight or obese.
The experts investigated the association between urban factors, such as ambient air pollution, green spaces, built environment, density of unhealthy food establishments, road traffic and road traffic noise, with various measures of childhood obesity and weight-related behaviours, such as a sedentary lifestyle.
Reporting their findings, lead author Jeroen de Bont said, "Higher levels of air pollution, traffic and noise were associated with higher body mass index and a higher likelihood of the child being overweight or obese."
The researchers came up with theories to explain this association. For example, air pollution could disrupt the molecular mechanisms that cause obesity by inducing inflammation or oxidative stress, hormone disruption and visceral adiposity, or noise could influence sleep deprivation and stress hormones, which could increase the risk of becoming overweight.
In addition, they found that the number of unhealthy food establishments in an area was also found to be associated with childhood obesity, but didn't find a link between the urban environment and the level of physical activity, sedentary behaviour and other weight-related behaviours.
They also discovered that kids living in more deprived areas on the outskirts of the city had higher rates of obesity despite the fact they were exposed to lower levels of air pollution, road traffic and noise and had access to more green spaces. The team intends to research the reasoning behind this finding further.
The study was published in the journal Environment International.