The Effects Of Air Pollution On Your Cholesterol

The Latest on How the Effects of Air Pollution May Affect Your Heart

(LifeWire) - It may sound implausible, but several studies have suggested that the effects of air pollution may extend to more than your lungs. The latest -- headed by researchers at University of California, Los Angeles -- found that ultrafine particles in polluted air and LDL (bad) cholesterol may work together to accelerate the narrowing and blockage of blood vessels.

In lab experiments, researchers combined diesel particles and the fatty acids that are found in LDL cholesterol and then cultured cells from the inner lining of human blood vessels in this mix. After extracting DNA from the cells for analysis, they found that the particles and fats worked together to activate the genes that promote cellular inflammation -- a major contributor to atherosclerosis, that is, the buildup of fatty deposits on artery walls.

The researchers then exposed mice with high cholesterol to diesel particles and observed the activation of some of the same gene groups in the animals' tissue. Their conclusion: The chemicals in pollution, which cause inflammation of the nose and lungs, also trigger vascular inflammation. And vascular inflammation can lead to cholesterol deposits and clogged arteries, which can lead to heart attack or stroke.

Past studies have also hinted at a link between polluted air and cardiovascular disease. In one, published in the journal Circulation, researchers at Brigham Young University reported that exposure to the tiny particulates emitted by automobiles, factories and power plants increased the risk of dying from cardiovascular disease in the U.S. Doctors took health data on 500,000 individuals that were collected by the American Cancer Society between 1982 to 1988 and compared them with pollution data from more than 150 cities across the U.S. The analysis suggested an association between elevated levels of air pollution and heart disease, including irregular heart rhythms, heart failure and cardiac arrest.

Another study in Circulation (July 2007) found that long-term exposure to air pollution from a nearby freeways or busy streets could increase the risk of heart disease and stroke. Researchers at the University of Duisburg-Essen, in Germany, examined nearly 4,500 adults for coronary artery calcification (CAC) and found that the closer an individual lived to heavy traffic, the higher the CAC.

While studies suggesting potential links between air pollution and cardiovascular disease are intriguing, say experts, their results are only preliminary. In any case, the relative risk of heart disease from air pollution is small compared to other known risk factors such as smoking, obesity or high blood pressure.

"We don't yet have hard evidence showing exactly how pollution leads to cardiovascular disease," notes Martha Daviglus, MD, a spokesperson for the American Heart Association and professor of preventative medicine at Northwestern University. "But until then, it's a good idea to take some precautions, especially if you are elderly or have respiratory or heart problems."

Some smart tips:

• Before exercising outdoors, check the Environmental Protection Agency's daily Air Quality Index, which provides information for more than 150 cities along with a health alert system that gives recommended changes in activity for days when pollution is high.
• Advocate for better air. Contact your state or local legislature to lobby for cleaner air. According to estimates, 19% of all U.S. counties with air-quality monitoring systems are presently not meeting EPA standards.
• Try to avoid exercising near heavy-traffic areas.

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