Having a Senior Moment? Blame Air Pollution

BY ON July 14, 2015

Woman looking confused

For weeks now, I’ve been trying to recall the name of a landscape architect I worked with a few years ago. I’ve remembered her first name, but her last name continues to elude me, yet I’m sure it’s there — lurking somewhere within the deepest, tallest stacks of my brain’s library.

An aging brain sometimes takes longer to retrieve certain information than it once did. Like many people over the age of 55, my brain’s agility is often, well…on my mind. So when I saw this recent headline in the New York Times, “Pollution May Age the Brain,” I sat up and took notice.

The researchers gathered their data from 1,403 women without dementia, who had initially enrolled in a large, 1996-1998 health study. For this new study, these women, aged 71 to 89, underwent structural brain MRI scans in 2005 and 2006 to measure the volume of their grey matter and normal-appearing white matter.

Then, drawing on the women’s residential histories and using air pollution data, the researchers estimated their exposure to air pollution from 1999 to 2006 — specifically their exposure to PM 2.5, tiny particulate matter that easily penetrates the lungs.

Sharpening the findings of a study we reported on this past spring, these latest findings, published in the Annals of Neurology, show a clear connection between exposure to air pollution and brain aging.

According to the study’s authors,

“In this large-scale study of residential exposure to fine particles and human brain structure, we found that older women had smaller brain volumes especially in the normal-appearing WM [white matter] if they resided in places with higher levels of long-term exposure to PM2.5 over 6-7 years preceding the brain MRI scans. The observed associations were not explained by demographic factors, socioeconomic status, lifestyle, and clinical characteristics we explored. These novel epidemiologic findings support the emerging concept that late-life exposure to ambient particulate air pollutants has a deleterious effect on brain aging.

In other words, writes the New York Times,

“Each increase of 3.49 micrograms per cubic centimeter cumulative exposure to pollutants was associated with a 6.23 cubic centimeter decrease in white matter, the equivalent of one to two years of brain aging.”

What exactly is white matter? When it comes to the brain, isn’t grey matter the important stuff? A bit of digging reveals that, in fact, my aging white matter is what has prevented me from retrieving that landscape architect’s full name.

According to James Balm in a post on BioMed Central, white matter is:

“… the subway of the brain – connecting different regions of grey matter in the cerebrum to one another. Imagine living in a city and having to walk from one area to another 5 miles away; transport makes this much more fluent and helps make your tasks easier. This is pretty much the same for your brain!”

Clearly, we need all the white matter we can hold onto. Thankfully, my research skills enabled me to finally unearth that name without “having to walk” too far. But what about later, when I’m really and truly old? All the exercise, good nutrition, and brainteasers in the world won’t stop the damage caused by air pollution.

Air pollution may be hurting our brains in other ways as well. A recent article in Mother Jones asks “Does Air Pollution Cause Dementia?”

According to its author, Aaron Reuben,

“ … it’s unclear whether particle pollution initiates degenerative disease or merely accelerates it. Still, the evidence so far suggests that pollution could be the most pervasive potential cause of brain disease that scientists have ever discovered.”

Given that, air pollution and its impact on the brain should be on everyone’s mind. To keep my own brain young and to protect those of future generations, I’ve added a large dose of activism to an already healthy lifestyle by participating in the Moms Clean Air Force Play-In and signing this petition:


TOPICS: Air Pollution