Widespread Effects

When researchers at Duke University Medical Center in Durham, North Carolina, asked women to recall a situation or event in their lives that made them angry, not only did the women's stress hormone levels spike, so did their cholesterol levels.

Researchers in the lab of Catherine M. Stoney, Ph.D., a psychology professor at Ohio State University, studied male and female airline pilots and found that pilots' LDL levels rose about 5 percent during times of high occupational stress.

While the reasons for the stress-cholesterol connection are still under study, researchers have some theories. One is that stress hormones send a message to your body fat to give up some fatty acids -- a way of ensuring you'll have enough energy if you have to move quickly. (This, of course, is an evolutionary response to the fact that our cave-dwelling ancestors were physically threatened quite often.) With that release -- as well as the release of triglycerides from the liver -- you have more fatty acids circulating in your blood for conversion to cholesterol, says Edward Suarez, Ph.D., associate professor of medical psychology at Duke.

But stress has heart-related effects far beyond cholesterol. Stress increases blood pressure, affecting the health of your arteries. And Dr. Stoney has found that even mild stress can increase blood levels of the amino acid homocysteine, which is a major contributor to heart disease. Stress can even affect how well you respond to medication if you already have heart disease.

In the long term, stress can wreak havoc in another way. When you're stressed, notes Dr. Suarez, you're less likely to live in a healthy manner. If you're constantly busy, intense, or harried, you're more apt to grab a bag of chips or a fast-food meal than sit down to a salad and steamed fish. You're probably skipping your daily walk, maybe taking up smoking again, or overdoing the wine. And if you need comforting, well, which are you going to choose: the gallon of premium ice cream or the apple?

Stress can also affect you cognitively, altering the way you view and react to the world around you. For instance, when chronically stressed you're more likely to forget things, overreact to little annoyances (think road rage), or expect negative things to happen to you. You're less likely to shine at work, you may find yourself unusually impatient or argumentative, or you may have problems relating to friends or family. You're also more likely to become depressed, and Depression itself is a risk factor for heart disease.

Hostility and the Heart

Everyone experiences stress now and then, but some people take stress a step further.

Surely you're familiar with the classic Type A personality -- the person who interrupts while you're speaking, tailgates the car in front, gives new meaning to the word "impatient," and is quick to snap when things go wrong. For years researchers knew that such people were more likely to have heart disease and heart attacks. Now they're learning why. A principal culprit, it seems, is hostility. At the lab of Catherine M. Stoney, Ph.D., researchers are focusing on a particular kind of hostility called aggressive responding. Aggressive responders tend to have a tough, somewhat cold-hearted view of the world and people around them. They agree with statements like, "I don't blame anyone for grabbing everything he can in this world," and, "I don't try to cover up my poor opinion or pity of another person."

The same researchers also found that people with a trait called cynical hostility were more likely to show areas of dead tissue, or evidence of small heart attacks, in their heart. These people would agree with statements like, "Most people would lie to get ahead," and, "People seek friends who are likely to be useful to them."

Hostility may be so physically damaging that, according to a study published in the November 2002 issue of health Psychology, it may trump overweight, cigarette smoking, and even high cholesterol as a predictor of heart disease. In the study, which looked at 774 men with an average age of 60, the researchers found that the more hostile the men were, the more likely they were to suffer from heart disease -- regardless of any other risk factors, including high cholesterol.