Traffic is one of those things that doesn't seem to have any positive, personal benefit unless you're the head of a multinational oil and gas conglomerate or you have some kind of fetish for being cursed and honked at over and over again.
Well, here's one more thing that may not win traffic jams any positive points for their PR team. The noise pollution that traffic produces might be associated with weight gain.
A study in the online edition of Occupational & Environmental Medicine on May 25 concludes that exposure to the noise produced by cars, trains and planes can "increase the risk of central obesity."
Researchers from the Karolinska Institutet in Stockholm studied the environmental traffic noise exposure of 5,075 Swedish residents since 1999, according to a release (PDF). Their health and work habits during 2002 to 2006 were investigated via a questionnaire, and the results of a medical exam on each participant were used as well.
The researchers concluded that the people who were regularly exposed to just one of the three tracked sources of environmental noise pollution at a noise level of at least 45 decibels were 25 percent more likely to have a larger waist -- and that doubled for people exposed to all three sources.
The study also found that waist size increased by .21 cm for women. There was also an association with increased waist to hip ratio, which was stronger for men.
The study doesn't claim that traffic noise is high in calories or otherwise a direct cause of body fat. Instead, researchers theorize that stress and the hormone cortisol are the culprits.
According to a video from the American Chemical Society, stress causes the body to bump up its cortisol production as a self-defense. However, the longer cortisol levels remain high, the more prone a person becomes to sickness -- and to cravings for foods that are high in fat.
So remember to keep in mind that stress comes from many sources, even those you don't consciously notice. That's right...they could be all around you, right now. Going right to your waist.