We know that what we eat and the air we breathe can determine, for better or for worse, our health. From today we know that what we hear can also affect the health of body and mind. In fact, external noise caused by traffic increases the risk of tinnitus, but also heart disease and dementia. This is what emerges from a very recent scientific research that appeared in the journal Environmental Health Perspectives thanks to the work of a Danish team (Cantuaria et al, Environ Health Perspect, 2023).
How diet, air and the surrounding environment affect our health
More and more scientific research demonstrates how important it is to eat healthily, limiting refined foods rich in fats and sugars which could cause an increase in inflammation, blood sugar and cholesterol. What we breathe also affects our health. In fact, breathing air loaded with pollutants and particulates can increase the risk of respiratory tract diseases but also, in the long term, of brain diseases. And can what we hear have a similar effect on our health? It seems so, based on various scientific researches.
Traffic noise and damage to our health
The noise generated by car traffic causes an increase in stress levels in people, through the activation of the hypothalamic-pituitary-adrenal axis. As a result, stress-related hormones, such as cortisol, are flooded into the body. In addition to this, nocturnal noise alters the quality and duration of sleep, preventing a good, restorative and regenerating sleep. Previous studies had already demonstrated that prolonged exposure to traffic noise can increase the risk of heart attack, stroke and even diabetes. The same Danish research group, author of the study we are discussing today, found an association between prolonged exposure to traffic noise and an increased risk of developing dementia, especially Alzheimer's disease, in the coming years (Cantuaria et al , BMJ, 2021). But what happens to hearing when we are subjected to continuous noise caused by traffic? The study we are talking about today tries to answer this question, focusing in particular on tinnitus. Tinnitus is a very common condition among the population and is characterized by the sensation of hearing a noise, a rustle or a whistle in the absence of an external noise source. Tinnitus can be very annoying and worsen the quality of life, increasing stress levels. The causes of tinnitus can be a damage or a disease to the middle ear, but the nervous system and stress also seem to play an important role.
Traffic noise and tinnitus, the study
Danish scientists have continued research aimed at understanding the effects of traffic noise on human health. For this purpose, the scientists analyzed data from 3.5 million people living in Denmark. For each of these people, the scientists evaluated, through the results of medical examinations, whether or not they suffered from tinnitus. Then, the scientists were able to calculate, for each study participant, the average exposure to traffic noise based on the residential address. What has emerged is that the more traffic noise you are subjected to on a regular basis, the greater the risk of developing tinnitus. In particular, every ten decibel increase in noise inside homes increases the risk of tinnitus by 6%. This link is believed to be explained by increased stress and worsening sleep quality.
Traffic noise, how we can defend ourselves
Living in houses full of traffic noise, therefore, can cause, in the long run, possible damage to health, increasing stress, sleep disturbances, the risk of developing heart disease, diabetes, dementia and, as we learned today, even tinnitus. But, in practice, what can we do to protect ourselves? Certainly, awareness in terms of urban planning and traffic management is helpful, with a reduction in the speed of cars at night or with the raising of noise barriers. However, these actions do not directly depend on us. What we can do is, if we have the possibility, to choose, as our bedroom, the room furthest away from the busy streets and not one with windows that look directly onto the traffic. If this is also not possible, it might be helpful to install anti-noise windows or use ear plugs, remembering, however, to follow excellent hygiene both with plugs and ears, asking your doctor or using the appropriate drops to clean the ears and avoid accumulations of earwax, which could make tinnitus worse.
