Also of significance are portion size and method of food preparation. These highly saturated fats tend to elevate cholesterol levels. Other important external factors include cigarette smoking, which lowers HDL levels, and exercise, which elevates HDL levels. Certain medicines can also adversely affect lipid levels. Other drugs such as beta blockers and the female hormone progesterone can lower HDL levels.
Internal factors influencing cholesterol levels are usually hereditary and beyond our control.
A careful family history can help determine the type of hereditary lipid abnormality. Familial hypercholesterolemia, one of the most common causes of very high cholesterol levels, is present in 1 out of every 500 people. It is typically carried by one parent and passed to half of the offspring. Patients with this disorder have cholesterol counts greater than 300 and may have cholesterol deposits not only in the arteries of the body, but even in other tissue such as muscle tendons. Symptoms of coronary disease are often present as early as age 40.