Obviously over eating and insufficient exercise are factors in increases in central body fat – but a study published in the Journal of Occupational & Environmental Medicine has, in addition, provided evidence of an association between exposure to traffic noise and larger waistlines.
Over 5,000 people who had taken part in a diabetes prevention programme in Stokholm underwent medical examinations including the measurement of blood pressure, the presence of diabetes, the extent of central body fat, waist-hip ratios and body mass indecies. Their home environments were also surveyed for the presence of three types of noise at greater than 45dB – the sound of a normal conversation in a living room or social setting. The types of noise arose from road traffic, trains or aircraft.
The researchers found that 54% had been exposed to one such noise source, 15% to two sources and 2% to all three. Exposure to any one of these noise sources was associated with a 25% chance of developing a larger waist, those exposed to two sources a higher chance than that and those exposed to three had a 50% chance of getting a larger waist.
It is thought that higher levels of continuous background noise result in higher levels of stress, which lead to higher cortisol levels in the blood stream. This has been known for some time to be a factor for central body fat deposition which greatly increases the risk of developing Type II Diabetes.
It follows from all this that it is reasonable to make efforts to control or reduce background noise. One obvious strategy would be to encourage an increase in electrically powered vehicles and a reduction in diesel powered vehicles both on the rails and on the roads – especially in urban environments.