Particulate Air Pollution and a High Fat Diet: A Potentially Deadly Combination

Morton Lippmann, Ph.D., Lung Chi Chen, Ph.D. and Sanjay Rajagopalan, MD
NYU School of Medicine and Mt. Sinai School of Medicine
P30ES00260 and R01ES13406

Background: Research supported by NIEHS over the previous ten to fifteen years has demonstrated links between cardiovascular disease and particulate matter air pollution. People with pre-existing conditions such as high blood pressure, previous heart disease, diabetes, respiratory disease, and high cholesterol have been shown to be especially vulnerable. Oxidative stress leading to inflammatory responses has been proposed as one reason for the resulting disease. Using a mouse predisposed to developing atherosclerosis, a team of NIEHS-supported scientists conducted studies to test whether exposure to environmentally relevant levels of particulate matter heightens the risk for atherosclerosis.

Advance: Mice fed a high fat diet and exposed to air with particulate matter for six months had a 40% increase in the thickness of plaque lining their carotid arteries compared to mice on the same diet breathing filtered air. The concentration of particulate matter was at a level considered safe under current national air quality standards. Particulate matter concentrations in ambient air are routinely observed at these levels in urban environments. The size of the individual particles is about half the size of a single red blood cell. In addition to causing the fatty plaque deposits, these particles also impaired heart muscle tone and caused swelling of blood vessels.

Implications: The results suggest particulate air pollution is more dangerous to the heart and circulatory system than previously known. The authors conclude that identification of the mechanisms and specific particle components responsible for these atherosclerotic effects could lead to the downward revision of particulate matter air quality standards. Further studies could also lead to therapeutic and preventive strategies to be employed for people with pre-existing conditions.

Citation: Sun Q, Wang A, Jin X, Natanzon A, Duquaine D, Brook RD, Aguinaldo JGS, Fayad ZA, Fuster V, Lippmann M, Chen LC, Rajagopalan S. Long-term Air Pollution Exposure and Acceleration of Atherosclerosis and Vascular Inflammation in an Animal Model. JAMA. 2005;294(23): p. 3003-3010.