Living Near Highways May Increase Dementia Risk

Living near a highway may have its perks, but a new study suggests that dwelling close to a high-traffic area can have serious implications for your cognitive health.

Ultimately, the closer you live to a major roadway, the more likely you are to develop dementia, says the study appearing Jan. 4 in The Lancet.

In a study of nearly 7 million people, Canadian researchers from Public Health Ontario (PHO) discovered that those living within 50 meters of a major roadway had a 7 percent greater chance of developing dementia than those who lived more than 300 meters away.

The researchers speculate that living close to a highway may expose someone to more air pollutants, which enter the body and wreak havoc on our bodies.

“Our study is the first in Canada to suggest that pollutants from heavy, day-to-day traffic are linked to dementia,” said co-author Dr. Ray Copes, Chief of Environmental and Occupational Health at PHO.

“We know from previous research that air pollutants can get into the bloodstream and lead to inflammation, which is linked with cardiovascular disease and possibly other conditions such as diabetes. This study suggests air pollutants that can get into the brain via the bloodstream can lead to neurological problems,” Copes added.

Characterized by a loss of cognitive faculties, dementia affects millions worldwide, and the rates are rising rapidly, according to the World Health Organization.

Broader Health Implications

The new research may be a signal for greater public health awareness of the links between cognitive health and the environment.

“Little is known in current research about how to reduce the risk of dementia. Our findings show the closer you live to roads with heavy day-to-day traffic, the greater the risk of developing dementia. With our widespread exposure to traffic and the greater tendency for people to live in cities these days, this has serious public health implications,” said Dr. Hong Chen, environmental and occupational health scientist at PHO.

Interestingly, the researchers noted a pattern of dementia rates and a person’s physical proximity to traffic and congestion. They reported an incremental decline in a person’s likelihood of developing dementia the farther away the person lived from a high-traffic area. While living within 50 meters led to a 7 percent increased risk, people living within 50 to 100 meters saw a 4 percent increase, and those between 100 to 200 meters had a 2 percent increase.

Related: Saunas May Lower Risk of Dementia and Heart Disease

There was no increased risk among those living within 200 to 300 meters. The researchers report that their findings should be taken into consideration when planning cities and traffic networks. “The findings of this paper could be used to help inform municipal land use decisions as well as building design to take into account air pollution factors and the impact on residents,” note the researchers in statement.

The researchers also assessed the risk of developing other neurological disorders, including Parkinson’s disease and multiple sclerosis, but they found no association between these specific disorders and heavy traffic.