Light cigarettes are just as harmful as regular cigarettes in their effect on the tiny blood vessels supplying the heart muscle, Turkish researchers report.

In addition to nicotine and carbon monoxide, there are thousands of other harmful components in cigarette smoke, and the cells lining the blood vessels of the heart are their main target, note Dr. Ozgur Ciftci of Baskent University Konya Teaching and Medical Research Center in Konya, and colleagues.

Ciftci and his team compared the effects of light and regular cigarettes on coronary microvessels using a measurement called the coronary flow reserve, which is an indication of the ability to increase blood flow to the heart muscle in response to exercise.

As described in the journal Clinical Cardiology, the researchers measured coronary flow reserve in 20 healthy, non-smoking volunteers before and after they smoked two regular cigarettes and after they smoked two light cigarettes. The two experiments were done 15 days apart.

Both types of cigarette impaired the study participants’ coronary flow reserve to the same degree, the researchers found.

They note that experienced smokers will often “transform even the lowest tar cigarettes into much higher tar cigarettes” by taking big puffs or even blocking filter vents used to dilute the smoke, but the study participants were all non-smokers, so they likely smoked light and regular cigarettes in the same way.

Ciftci and his colleagues conclude: “Light cigarette smoking has similar acute detrimental effects on coronary microvascular function and coronary flow reserve as does regular cigarette smoking.”

SOURCE: Clinical Cardiology, April 2009.