On the street where you live

Over the Thanksgiving holiday, the highways will be jam-packed with traffic. And you might not be able to avoid them entirely over the next few days, if you’re planning to visit family and friends.

But highways aren’t just a problem during the holidays. As a large of number of studies show, it’s a good idea to steer clear of them year round, if you can.

As you would expect, when you live near a busy road, you increase your exposure to pollution. This exposure can increase your risk of suffering from a respiratory condition such as asthma. In fact, some research shows just breathing the air in dense urban areas is equivalent to the adverse health effects of smoking an extra half-a-pack of cigarettes per day.

Furthermore, researchers now link living near a major roadway to many other chronic diseases beyond asthma. So it seems “On the Street Where You Live” isn’t just the title of a song from Lerner and Loewe’s Broadway musical My Fair Lady, it’s also a major risk factor for chronic diseases.

In fact, earlier this year, the Journal of the American Heart Association published research showing a link between high blood pressure and living close to a highway.

For this study, researchers followed about 5,000 postmenopausal women. The women who lived within about 100 yards to a highway had a 22 percent higher risk of hypertension compared to those who lived at least a half-mile away. Researchers suggested greater exposure to traffic-related pollution, noise, and stress as potential causes.

In 2012, a study published in Circulation found that heart attack survivors who resided less than 328 feet from major highways had a 27 percent higher death rate over 10 years compared to those that lived at least 3,280 feet away. Again, the researchers cited air pollution, noise, and stress as possible explanations.

And a new study in Circulation found that women who reside near highways run a greater risk of sudden cardiac death. For this study, researchers observed 523 cases of sudden cardiac death among 10,000 women with an average age of 60 years. The women who lived within 164 feet of a highway had a 38 percent higher risk of sudden cardiac death compared to women who lived more than one-third of a mile away. Plus, for every 328 feet closer to the highway, there was a 6 percent increase in risk of death.

Researchers link proximity to highways to other health problems as well…

In a 2013 study published in the Journal of Epidemiology and Community Health, researchers found that men and women who lived closer to a highway had higher rates of stroke as well as poorer kidney function. This study followed 1,100 men and women.

Of course, exposure to traffic and pollution also affects children…

In 2013, researchers published a study in the medical journal Diabetologia that analyzed the effect of traffic exposure on 400 children over age 10. They found a disturbing connection between traffic-related air pollution and insulin resistance, the precursor to Type II diabetes. For every increment of 1,640 feet closer to a highway, the children had a 7 percent greater risk of developing insulin resistance.

Finally, a 2007 Harvard study evaluated 202 Boston-area children with an average age of 10 years. Children who lived and attended school in areas with higher traffic scored an average of four points lower on IQ tests.

Can we really blame all these problems simply on increased exposure to air and noise pollution? Maybe not.

As I’ve always said, human health is rarely that simple.

In fact, experiments on lab animals show that simply living in busy, crowded, congested conditions causes stress–regardless of air quality, noise, or any other factor.

Since the Industrial Revolution began 200 years ago, researchers have noted that people who live in crowded, urban conditions have poor health. And I’m not just talking about more communicable infections. We observe more nutritional deficiencies, degenerative diseases, and mental health conditions in crowded, urban areas as well. (I’ll tell you more about the impact of urbanization on health next month in the Daily Dispatch.)

In the later 1800s, many physicians advised their sick patients to take a “rest cure,” “nature cure,” or even “west cure.” They considered it the best course for treating almost any disease. And amazingly, these cures had 50 percent success rates for chronic infections before antibiotics became available.

Of course, we often associate city life with better jobs, culture, and other amenities. But you’d better think twice before moving to the city for better health. Perhaps the development of internet technology will allow more and more people to “telecommute.” That way, they can keep their big city job, but live in a more healthful environment, as British novelist Thomas Hardy once observed, “far from the maddening crowd.”

The rise of emerging infectious diseases–such as Ebola and even influenza–is only one consideration for keeping a healthy distance from crowds.

Getting away from unhealthy cities and back in touch with nature might be the single best solution for health, sanity–and the fate of the country itself, as long envisioned by Thomas Jefferson’s concept of a healthy, agrarian democracy.

Always on the side of science,

Marc S. Micozzi, M.D., Ph.D.

Sources:

  1. “Residential Proximity to Major Roadways and Prevalent Hypertension Among Postmenopausal Women: Results From the Women’s Health Initiative San Diego Cohort,” J Am Heart Assoc 2014; 3: originally published 10/1/2014
  1. “Residential Proximity to Major Roadway and 10-Year All-Cause Mortality After Myocardial Infarction,” Circulation 5/7/2012; 125: 2197-2203
  1. “Residential proximity to major roadways and renal function,” J Epidemiol Community Health 2013; 67(8):629-34
  1. “Long-term exposure to traffic-related air pollution and insulin resistance in children: results from the GINIplus and LISAplus birth cohorts,” Diabetologia, 12 February 2013
  1. “Association of Black Carbon with Cognition among Children in a Prospective Birth Cohort Study,” American Journal of Epidemiology 11/15/2007; 167:280-286
  1. “Roadway Proximity and Risk of Sudden Cardiac Death in Women,” Circulation American Heart Association, published online before print 10/13/2014