Here’s another reason to despise traffic: Noisy city streets might increase the risk of developing dementia.

A massive study out of Denmark involving two million adults age 60 and older found that long-term exposure to excessive traffic and transportation noise was associated with a higher risk of dementia, especially Alzheimer’s disease.

Remarkably, researchers estimated noise levels for every residential building in Denmark for the investigation.

Better understanding the risk of this neurological disorder is critically important as more than 55 million people globally have been diagnosed with dementia. And that figure is expected to climb to 150 million by 2050.

Long-term exposure to noise isn’t just a risk for our mental health. Previous studies also have associated it with health problems like obesity, diabetes and coronary disease.

Scientists have a few ideas about why noise causes problems for the brain. It’s thought, for example, that fragmented sleep can lead to alterations to the immune system, oxidative stress and higher levels of systemic inflammation.

The encouraging news is that noise pollution is a risk factor that, to some extent, can be controlled, unlike a genetic predisposition to a disease. Ear plugs or government regulation to reduce traffic noise — even better sound insulation in the home — might alleviate the issue to a significant degree.

We can also reduce our odds of developing dementia by living healthy lives. Investigators have found eating well, exercising, and staying mentally active, among other things, can keep our minds sharp as we sail into our golden years.

And if you find yourself in traffic, do everyone a favor: Lay off the horn.