Mental stress raises cholesterol

Stress may raise cholesterol levels in healthy adults

Washington: A new study by the American Psychological Association has found that mental stress over a period of time can raise a person's lipid levels, or in other words, it can increase cholesterol levels in healthy adults. According to the study, published in the recent issue of Health Psychology, in a sample of 199 healthy middle-aged men and women, researchers Andrew Steptoe, D.Sc., and Lena Brydon of University College London examined how individuals react to stress and whether this reaction can increase cholesterol and heighten cardiovascular risk in the future. Changes in total cholesterol, including low-density lipoprotein (LDL) and high-density lipoprotein (HDL), were assessed in the participants before and three years after completing two stress tasks.

The stress testing session involved examining the participants' cardiovascular, inflammatory and hemostatic functions before and after their responses to performance on moderately stressful behavioral tasks. The stress tasks used were computerized color- word interference and mirror tracing. The color-word task involved flashing a series of target color words in incongruous colors on a computer screen. At the bottom of the computer screen, four names of colors were displayed in incorrect colors. The object of the task was to match the name of the color to the target word. The other task used was mirror tracing, which required the participant to trace a star seen in a mirror image. The participants were told to focus more on accuracy than on speed in both tasks. At the follow up three years later, cholesterol levels in all the participants in the study had gone up, as might be expected through passage of time.

However, individuals with larger initial stress responses had substantially greater rises in cholesterol than those with small stress responses. The people in the top third of stress responders were three times more likely to have a level of 'bad' cholesterol above clinical thresholds than were people in the bottom third of stress responders. The researchers speculate on the reasons why acute stress responses may raise fasting serum lipids. One possibility may be that stress encourages the body to produce more energy in the form of metabolic fuels - fatty acids and glucose. These substances require the liver to produce and secrete more LDL, which is the principal carrier of cholesterol in the blood. Another reason may be that stress interferes with lipid clearance and a third possibility could be that stress increases production of a number of inflammatory processes like, interleukin 6, tumor necrosis factor and C-Reactive protein that also increase lipid production.
-Nov 23, 2005