Aircraft, rail and road noise double danger of obesity
LIVING with transport noise can make you fat, scientists claimed yesterday.
People regularly exposed to a combination of road, rail and plane noise are almost twice as likely to put on weight as those living in a peaceful environment.
But just living next to a busy road can increase the risk of middle- age spread, and in turn diabetes and heart problems.
Since 1999, Swedish researchers have studied the effect of exposure to road traffic, rail and aircraft noise on 5,075 middleaged people living in five suburban and rural areas around Stockholm.
Their report looked at how noise causes stress which can increase the production of the hormone cortisol.
This is thought to have a role in central obesity – the build- up of fat in the middle of the body.
Traffic noise can also cause sleep disturbance which alters appetite control.
The researchers, from Stockholm’s Institute of Environmental Medicine, wrote: “The effects of noise were mainly seen for markers of central obesity, such as waist circumference and waist- hip ratio, rather than for generalised obesity.”
Of the people in the Swedish study just over half had been exposed to one source of traffic noise, 15 per cent to two sources; and two per cent to all three. Thirty per cent were normally exposed to levels below a moderate 45 decibels.
The study, in the British Medical Journal’s Occupational and Environmental Medicine, found that when women were exposed to road traffic noise their waist size increased by 0.21cm ( 0.08 inches) for every five decibels.
Men’s waist- hip ratio increased by 0.16cm for every five decibels.
The heightened risk of obesity rose from 25 per cent among those exposed to only one noise type to almost double for those exposed to all three sources.
The strongest link was with aircraft noise.
Commenting on the study, Dr Anna Hansell of Imperial College London said: “A number of recent studies have found associations between transport noise and high blood pressure, heart disease and stroke.
“This study investigates possible mechanisms that might support and help explain these findings. Here, the theory is that noise acts as a stressor and increases cortisol production, which might lead to increased fat deposition around the midriff.
“While interesting, this is one of the first studies to look at the link between waist size and traffic noise, so it’s definitely too soon to be able to blame your increasing waistline on traffic noise.
“Eating a sensible diet and taking regular exercise remains the best way to help prevent a midriff bulge.”