Scientists find link between air pollution and high cholesterol

By Elaine Schmidt

UCLA scientists recently came up with one more good reason why people living and working in Los Angeles should keep their cholesterol levels in check.

They found a link between air pollution — diesel exhaust — and atherosclerosis, or hardening of the arteries, which significantly increases one's risk for heart attack and stroke. In other words, if you have high cholesterol, stay away from air pollution.

"When you add one plus one, it normally totals two," said principal investigator Andre Nel, chief of nanomedicine at the David Geffen School of Medicine and a researcher at the California NanoSystems Institute.

"But we found that adding diesel particles to cholesterol fats equals three. Their combination creates a dangerous synergy that wreaks cardiovascular havoc far beyond what's caused by the diesel or cholesterol alone."

Published in the July 26 edition of the online journal Genome Biology, the findings are the first to explain how fine particles in air pollution conspire with artery-clogging fats to switch on the genes that cause blood vessel inflammation and lead to cardiovascular disease.

The researchers studied the interaction between diesel exhaust particles and the fatty acids found in low-density lipoprotein (LDL) cholesterol — the "bad" type of cholesterol that leads to artery blockage. When they combined the diesel particles and oxidized fats and cultured them with cells from the inner lining of human blood vessels, they found the combination activated the genes that promote cellular inflammation — a major risk factor for atherosclerosis, said Jesus Araujo, assistant professor of medicine and director of environmental cardiology.

"The interaction left a genetic footprint that reveals how interaction between the particles and cholesterol accelerates the narrowing and blockage of the blood vessels," Araujo noted. "Our results emphasize the importance of controlling air pollution as another tool for preventing cardiovascular disease," said first author and UCLA cardiology researcher Ke Wei Gong.