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Prolonged exposure to nicotine, either from a real cigarette or the battery operated device can damage the heart (lindsay-fox/Flickr)

Regular cigarettes contain about 4,000 toxic chemicals and have been linked to a wide range of diseases like lung cancer, heart disease and stroke. Hence, electronic cigarettes were considered safer than the traditional cigarettes as they provide less nicotine than the latter, and do not contain the cancer-causing toxins or produce harmful substances associated with smoking real cigarettes (tar and carbon monoxide). E-cigarettes are also widely promoted to help people quit smoking.

However, according to a new study presented at the American Society of Cell Biology annual meeting in New Orleans, a prolonged exposure to nicotine, either from a real cigarette or the battery operated device can damage the heart, CNN reported.

Exposure to nicotine is widely known to increase blood pressure and heart rate. Apart from that, nicotine exposure has long been linked to atherosclerosis, the accumulation of plaque on the artery walls. The narrowing and hardening of arteries are well-known factors that pose risk to the heart.  The build-up of fatty deposits in the artery wall reduces blood flow, causing blood clots, heart failure, strokes, high blood pressure, renal failure, leg pains and aneurysm (swelling of blood vessels).

For the study, researchers led by Chi Ming Hai from the Brown University in the US exposed heart cells collected from humans and rats to nicotine, nearly for six hours. They found that the nicotine exposure caused the formation of podosome rosettes, further causing holes in the cells. The process can lead to the accumulation of plaque and development of atherosclerosis.

"Cigarette smoke contains thousands of chemicals, but nicotine is the major chemical that causes cigarette addiction," Hai said in a statement to Healthline. "In my opinion, if taking nicotine for a short time can lead to complete cessation of smoking, e-cigarette included, then it will be beneficial to take nicotine for a short time as a bridge to smoking cessation. However, our data suggest that long-term consumption of nicotine by e-cigarette smoking is likely to increase the risk of developing atherosclerosis by stimulating invasion of vascular smooth muscle cells."

Safety and risks associated with the e-cigarettes were always a topic of discussion since it was first launched in the Chinese markets in 2004.  A group of experts attending the E-Cigarette Summit at the Royal Society in London, last month claimed that switching from traditional to electronic cigarettes could help reduce smoking-related deaths across the world.  However, a team of American researchers reported later that e-cigarettes cannot help stop smoking, on the other hand, can turn youngsters into dual smokers, making them smoke more nicotine.  Last week, researchers reported that smoking e-cigarettes provides more toxins than real cigarettes.