Research Confirms Common Sense: Pollution Is Bad for Your Brain

2 studies provide similar findings that air pollution has neurodegenerative effects
February 13, 2020 Updated: March 2, 2020

We’ve known the health hazards of air pollution since the dawn of the industrial age, but while its adverse effects on our hearts, lungs, and immunity are well established, researchers have now confirmed a decades-old suspicion—air pollution also damages the brain.

Two recent and independent studies came to very similar conclusions on the detrimental effects of air pollution at opposite ends of the age spectrum.

The first study, done at Cincinnati Children’s Hospital Medical Center and published in PLOS One, investigated the effects of traffic-related air pollution on children’s brains. They studied a group of 147 12-year-old children who had been exposed to either high or low amounts of air pollution at 1 year of age. The children had been recruited before the age of six months and were a subset of an earlier study looking at the effects of pollution on allergies. Researchers found a 3–4 percent loss in gray matter volume and a reduction in cortical thickness in the brains of children who had higher exposures to air pollution.

Different areas of the brain showed different volume loss and thinning. Using magnetic resonance imaging (MRI), researchers concluded that higher levels of air pollution damaged the development of the sensorimotor cortex, frontal cortex, and cerebellum. These areas of damage were noted in 12-year-old children well over a decade after the period of pollution exposure.

The second study, done at the University of British Columbia and published in Environmental Health, examined the connections between neurodegenerative diseases such as Alzheimer’s, Parkinson’s, multiple sclerosis (MS), and dementia to how far away the participants lived from major roads and highways. The investigators reviewed the data of more than 678,000 residents of the Metro Vancouver area. They found that participants who lived less than 165 feet (50 meters) from a major road or less than 500 feet (150 meters) from a highway were at higher risk for developing neurodegenerative diseases. They concluded that increased exposure to air pollution was the likely cause of this increased risk.

The corroborating nature of these independent studies illustrates the broad and cumulative effects of air pollution on the brain throughout our lives. Whether it be a narrowly defined period early in life or ongoing exposure later in life, the facts indicate that the more air pollution you breathe, the more brain cells you will lose.

While health-minded people are increasingly aware of the concept of detoxification, not enough focus has been placed on, arguably, the largest source of toxicity we face—the air we breathe.  You can modify most aspects in your lifestyle, but changing the air you breathe is particularly difficult since it requires you to change where you live or work.

Cars are the primary source of air pollution. While eliminating air pollution from cars is ideal, it’s also unlikely for decades given that electric cars only comprise one in 250 new car sales.

The next most effective solution would be to avoid high-pollution areas. This is not a huge problem for the 20 percent of Americans who do not live in cities but with 80 percent of the American population living in urban areas, this is easier said than done. Even within an urban area, exposure to air pollution will vary greatly depending on how far your home is from major roads, highways, and other high traffic areas.

Rather than viewing air pollution as something to eliminate or leave, what about considering where in our daily life we are able to control the quality of the air we breathe. You would want to choose an enclosed area where you consistently spend much of your day. Your bedroom would be an ideal choice. A medical-grade, true high-efficiency particulate air (HEPA) filter with carbon or zeolite would significantly reduce the air pollution you breathe while you sleep. This could be a particularly effective intervention for children under the age of 1 due to the increased sensitivity of their developing brains and their relatively longer period of sleep compared to adults.

Another strategy would be to optimize your body’s detoxification potential. Detoxification is a complex system with hundreds of biochemical pathways. Like any system in the body, it possesses only a finite amount of resources. A metabolism overwhelmed on a daily basis with junk food, artificial ingredients, tobacco, alcohol, and recreational drugs (that’s the shortlist) won’t have much spare capacity to combat toxins in the air we breathe. By living as cleanly as possible, removing the toxic burdens we can control, we allow our detox pathways to have the resources necessary to clean out the toxic burdens we do not have much control over.

That being said, it’s worth putting air pollution in America from a historical perspective. Because of the Clean Air Act, the six major air pollutants (particulate matter, ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead) have all dropped 72 percent since 1970. This figure is even more impressive when you consider in that same period growth of 200 percent in the economy and 150 percent in the number of miles we drive.

While change at the personal level can do much, with a problem as pervasive as air pollution, that is not enough. Stricter regulations to limit the emissions of the six major air pollutants that we know are damaging us today would improve the health of many people in urban areas.

Armen Nikogosian, M.D., practices functional and integrative medicine at Southwest Functional Medicine in Henderson, Nev. He is board-certified in internal medicine and a member of the Institute for Functional Medicine and the Medical Academy of Pediatric Special Needs. His practice focuses on the treatment of complex medical conditions with a special emphasis on autism spectrum disorder in children, as well as chronic gut issues and autoimmune conditions in adults.