We know that high blood pressure, elevated cholesterol and smoking aren’t good for the heart. Well, it turns out loud noise is another risk factor your doctor may not want to keep quiet about.
That noisy little headline comes from researchers at the Massachusetts General Hospital. They studied 499 people with an average age of 56.
At the beginning of the study period, all of them were free of cardiovascular disease. Over time, they tracked how many of the test subjects got heart attacks and strokes. The researchers used the home addresses of study participants to estimate the level of ambient noise where they resided.
Compared to people who lived with lower levels of noise, those with the highest levels of chronic noise exposure were three times more likely to have a heart attack, a stroke or other major cardiovascular event.
The study’s authors said typical sources of heavy chronic noise exposure include close proximity to a highway, a major airport or a busy traffic zone.
Commercial aircraft on takeoff produce noise levels above 120 decibels. A telephone ring produces about 80 decibels and a jackhammer about 100. Highway traffic noise ranges from 70 to 80 decibels at a distance of 15 metres from the highway.
The researchers found that people with the highest levels of noise exposure had higher levels of brain activity inside the amygdala.
The test subjects with higher activity inside the amygdala also had greater amounts of inflammation in their arteries inside the heart and the brain. Doctors know from other studies that inflammation of the arteries is necessary for the development of heart disease and strokes.
In the current study, the researchers found that high levels of activity inside the amygdala actually increased the level of inflammation inside the coronary arteries.
Air pollution, smoking and diabetes are other known factors that cause inflammation of the arteries.
In this study, when the researchers took those factors into account, noise still turned out to be a major contributor to inflammation and therefore to the risk of heart attacks and strokes.
Rising rates of noise are happening everywhere. Anyone who lives in a city anywhere on the planet should be concerned about the health impact of exposure to excessive noise.
Until now, we’ve chalked up rising levels of noise from busy highways, traffic zones and airports to progress and prosperity. Now, we see that there’s a hidden danger to our health.
And it’s something your body won’t let you escape. You may be able to tune the noise out of your conscious mind, but your brain and your heart do not develop tolerance to noise. If anything, your arteries may become even more prone over time to damage caused by noise.