Smoking and Heart Disease

Smoking is extremely injurious to heart health — smoking tobacco products, especially cigarettes, poses significant risks to the cardiovascular system, making it a leading cause of heart disease, strokes, and other related complications. The detrimental effects of smoking on heart health are multifaceted and are a result of the various harmful substances present in tobacco smoke.

1. Impact on Blood Vessels:
Cigarette smoke contains a plethora of harmful chemicals, including nicotine, carbon monoxide, and various carcinogens. When these substances are inhaled, they lead to the constriction of blood vessels, a process known as vasoconstriction. This narrowing of blood vessels restricts blood flow and oxygen delivery to the heart and other vital organs. Over time, this can contribute to the development of atherosclerosis, a condition in which fatty deposits build up on the inner walls of arteries, further restricting blood flow.

The chemicals in tobacco smoke also trigger inflammation within the blood vessels, leading to damage to the arterial walls. As a response to this damage, the body tries to repair the vessels by depositing cholesterol and other substances at the site of injury. Over time, these deposits can accumulate and form plaques, which can rupture and lead to blood clot formation. If a clot obstructs a narrowed artery, it can result in a heart attack, where a portion of the heart muscle is deprived of oxygen and nutrients, potentially causing permanent damage.

2. Increased Blood Pressure:
Smoking elevates blood pressure, which is a significant risk factor for heart disease. Nicotine, one of the primary components of tobacco, stimulates the release of adrenaline and other stress hormones, leading to an increase in heart rate and blood pressure. This constant strain on the cardiovascular system can contribute to the development of hypertension (high blood pressure), which is a major contributor to heart disease, stroke, and other vascular issues.

3. Reduced Oxygen Supply:
Carbon monoxide, another toxic compound found in cigarette smoke, has a high affinity for haemoglobin in red blood cells, binding to it more strongly than oxygen. This results in a reduced capacity of the blood to transport oxygen throughout the body. In the context of heart health, this diminished oxygen supply can place additional stress on the heart, which needs a constant and ample supply of oxygen to function optimally.

4. Abdominal Aortic Aneurysm 
An abdominal aortic aneurysm is characterised by a localised bulge or weakened section that develops in the abdominal segment of the aorta, the body’s primary artery responsible for distributing oxygen-rich blood. Smoking accelerates its development by weakening the artery’s walls, rendering a rupture more likely. Most fatalities associated with this condition are linked to smoking, with women being more vulnerable to the disease than men who smoke. 

Autopsies have revealed indications of initial constriction in the abdominal aorta among individuals who engaged in smoking during their adolescence. This early-life exposure to tobacco has been implicated in fostering the narrowing of this crucial artery, thereby underscoring the lasting impact of smoking on cardiovascular health.

However, the good news is that the negative effects of smoking on heart health can be partially reversed by quitting smoking. While the risk of heart disease remains elevated for a time after quitting due to the cumulative damage caused by smoking, the risk gradually decreases as the body starts to repair itself. Within a year of quitting, the risk of heart disease drops significantly, and over time, the risk approaches that of a non-smoker.