Exposure to road traffic noise may up obesity risk: Study

Long-term exposure to road traffic noise may increase the risk of obesity, according to a study.

Researchers from the Barcelona Institute for Global Health (ISGlobal) in Spain analysed the data from 3,796 adults.

"Our analysis shows that people exposed to the highest levels of traffic noise are at greater risk of being obese," said Maria Foraster from ISGlobal.

"For example, we observed that a 10 decibel (dB) increase in mean noise level was associated with a 17 per cent increase in obesity," Foraster said.

The study, published in the journal Environment International, also analysed exposure to noise generated by aircraft and railway traffic.

It found no significant associations except in the case of long-term exposure to railway noise, which was associated with a higher risk of being overweight but not of obesity.

Being overweight was only associated with exposure to traffic-related noise in the cross-sectional analysis.

The researchers found no association between noise exposure and body mass index measured continuously throughout the longitudinal analysis.

"Our study contributes additional evidence to support the hypothesis that traffic-related noise affects obesity because the results we obtained in a different population were the same as those reported by the authors of earlier studies," Foraster said.

"Nevertheless, more longitudinal studies are needed to confirm the association and to examine certain inconsistencies in the data which, to date, have prevented us from formulating an explanation accepted by the scientific community as a whole," Foraster said.

Sustained exposure to noise pollution is a widespread public health problem that is more serious than previously thought. Noise generates stress and affects our sleep, researchers said.

It alters hormone levels and increases blood pressure. Among other effects, sleep disturbance deregulates glucose metabolism and alters the appetite, they said.

"In the long term, these effects could give rise to chronic physiological alterations, which would explain the proven association between persistent exposure to traffic-related noise and cardiovascular disease or the more recently discovered associations with diabetes and obesity," said Foraster.

"Our findings suggest that reducing traffic-related noise could also be a way of combating the obesity epidemic," she said.