Which lifestyle factor is a major contributor to coronary artery disease?

Smoking is a major contributor to coronary artery disease due to its detrimental effects on the cardiovascular system. It causes damage to the blood vessels and promotes the development of atherosclerosis, which is the buildup of plaque in the arteries. This plaque restricts blood flow and can lead to heart attacks and other serious cardiovascular events.

Moreover, smoking increases the levels of carbon monoxide in the blood, which reduces the oxygen-carrying capacity of hemoglobin, putting extra strain on the heart. It also reduces HDL cholesterol (the "good" cholesterol) while simultaneously increasing LDL cholesterol (the "bad" cholesterol), further exacerbating the risk of plaque formation. Additionally, the harmful chemicals in cigarette smoke contribute to inflammation and increased clotting in the arteries, heightening the risk of coronary artery disease.