Smoking has a negative effect on your cholesterol levels. High cholesterol levels, specifically high LDL, or bad cholesterol, can lead to fatty streaks forming in your arteries. These fatty streaks attract more cholesterol-enriched platelets to accumulate and eventually lead to narrowing of the opening in your arteries. This narrowing of your arteries can become blocked by a blood clot and lead to a heart attack or stroke.
Nicotine
Smoking delivers nicotine to your body through your blood stream. Nicotine can accelerate hardening of your arteries by oxidizing the fatty streaks made from LDL cholesterol deposits in your arteries. Nicotine can also build up in your blood and increase its thickness, according to the Health Care Center. These changes put extra strain on your heart and weaken it over time because of the increased pumping action your heart has to perform.
Fat Metabolism
Nicotine causes a release of norepinephrine and epinephrine in the blood stream, which produces a surge of energy experienced with smoking. Nicotine produces a false fight or flight from increased adrenaline from norepinephrine and epinephrine; this makes your body release fatty acids into your blood stream. The increased level of fat in your blood becomes oxidized over time by free radicals from the toxins in cigarette smoke, according to Louiza Patsis in "Nicotine: Tolerance and its Effects on the Cardiovascular System, Lungs and Fetus." The oxidation of the fatty acids further contributes to the fatty streak buildup in your arteries.
Blood Clots
Smoking increases the formation of blood clots in your arteries. You have a protein called plasminogen activator inhibitor-1 that regulates the breakdown of blood clots. When PAI-1 levels are high from smoking, an enzyme called fibrinolysis is inhibited. Fibronolysis breaks down clots and keeps your arteries from becoming clogged by them. Smoking increases the activity of blood clot formation by downplaying fibronolysis by increasing PAI-1. Your risk of stroke or heart attack increases because of increased blood clots circulating in your blood stream.
Blood Vessels
Smoking causes your blood vessels to constrict. Nicotine acts as a constrictor of your blood vessels. This becomes a problem with fatty streaks that have built up in your arteries. The lumen, or opening, of your arteries becomes smaller. As the lumen becomes smaller, platelets start to collect in areas where cholesterol has deposited, as stated by Patsis. Your blood pressure can increase due to the constricting nature of smoking and the decreased lumen size due to fatty streak buildup in your arteries.
HDL Cholesterol
Smoking decreases your HDL, or good, cholesterol level. The suppression of HDL cholesterol production in your body by smoking helps your LDL cholesterol levels to rise and accumulate in your arteries. HDL cholesterol is beneficial because it removes the accumulated LDL cholesterol before it hardens. With less HDL cholesterol circulating, fatty streaks can increase and harden over time leading to atherosclerosis, which is hardening of the arteries.
References
- The Health Care Center: The Relationship Between Smoking and Heart Disease
- NYU Toxicology: Nicotine: Tolerance and its Effects on the Cardiovascular System, the Lungs and the Fetus
- American Heart Association: Nicotine Increases Plasminogen Activator Inhibitor-1 Production by Human Brain Endothelial Cells via Protein Kinase C--Associated Pathway
