Smoking can greatly increase the risk of heart disease and stroke. Recent study has shown that smoking can cause significant damage to arteries, and the damage go on worsening with the passage of time. Increased arterial stiffness is linked with increased risk of heart disease and stroke.

Dr. Stella Daskalopoulou, an internal medicine and vascular medicine specialist at McGill University Health Center in Montreal, compared the data collected from 10 smokers and 10 non smokers, ages 18 to 30. The smokers enrolled in the study smoked five to six cigarettes a day.

For the study, the smokers were asked not to smoke for 12 hours before their first exercise test. Then smokers were allowed to have one cigarette before the second exercise test. Smokers were asked to chew a nicotine gum before the final test.

Data analysis revealed that arterial stiffness in non-smokers decreased 3.6 percent, whereas arterial stiffness of smokers increased 2.2 percent after exercise. Arterial stiffness of smokers increased 12.6 percent after chewing nicotine gum and 24.5 percent after having one cigarette.

Daskalopoulou said, "In effect, this means that even light smoking in otherwise young healthy people can damage the arteries, compromising the ability of their bodies to cope with physical stress, such as climbing a set of stairs or running to catch a bus. It seems that this compromise to respond to physical stress occurs first, before the damage of the arteries becomes evident at rest."