Nairobi is polluted. First, breathing air in Nairobi is very likely to kill you. Second, there is a lot of noise in Nairobi, noise that has been found to be a leading cause of weight gain. Typically, people avoid gaining weight by dieting, exercising and medication. From today onwards, to lose weight effectively you may want to live in a quiet environment. That is if the results of a new study is to be taken seriously. According to a study published in the online edition of Occupational & Environmental Medicine on May 25th , noise pollution from traffic leads to gaining weight and 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. 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. The findings were not influenced by socioeconomic factors, lifestyle, or exposure to ambient air pollution from local road traffic. But age was an influential factor, with associations between central obesity and road traffic noise only found for those below the age of 60. 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 exposed to sickness and to cravings for foods that are high in fat.
Nairobi being one of the busiest cities in Africa was ranked by IBM as the worst cities for commuting alongside mega-jam like Mexico City and Beijing. Buses, taxis, motorcycles and private cars all compete for road in a city that has almost 3.5 million people. The risks of having larger waists or gaining fat are high.