"The problem is that many individualsand probably including myselfeat a diet that is very excessive in all the wrong kind of fats, of which we are talking about animal fats and dairy fats, and therefore we get our cholesterol up too high," says Dr. Dehmer.
But when you exercise, HDL cholesterol goes upand that's a good thing. "The bottom line is that there are some people out there who have fairly high levels of HDL cholesterol," says Stephen Nicholls, MBBS, PhD, a research cardiologist at the Cleveland Clinic. "That may drive their total cholesterol to look higher than it actually is in terms of how bad that level is."
How cholesterol affects the heart
If LDL cholesterol is too high, some is absorbed into the artery walls, where it acts like an irritant that triggers inflammation in the body. White blood cells crawl into the artery wall and start "gobbling up fatty particles" in a fruitless effort to heal the damage, says Dr. Dehmer.
The end result is big, fatty deposits in the blood vessels. This causes the vessels to become stiff, narrow, and less responsive to triggers to expand and constrict, a process that ensures a steady flow of life-giving oxygen to the body's tissues. (While you may think of blood vessels as akin to the plumbing in your house, they're more dynamic; they constantly adapt to meet the body's needs.)
The biggest danger, however, is to the heart. The arteries that cover the surface of the heart are particularly prone to clogging. Once fatty plaques clog these blood vessels, blood flow to the heart tissue is reduced. This can cause chest pain, or angina.
If plaque ruptures, a clot can form and cause a heart attacka dramatic decline in the blood supply that causes heart tissue to die. (To find out if youre at risk for having a heart attack, take this test.)