Stress keeps heart-damaging fats in the bloodstream longer
18 February 2002Stress can slow the clearing of harmful fats linked to heart disease from the bloodstream.
This is the finding of a new study which shows that short periods of psychological stress in humans can cause the body to take longer to clear triglycerides, which are heart-damaging fats, from the bloodstream.
It has been shown previously that short-term stress can cause levels of heart-damaging fats to rise in the bloodstream, but this study provides the first evidence that stress hampers the body in its ability to clear the fats from the bloodstream.
This would suggest that eating snacks or meals rich in fat, during periods of stress, could lead to harmful fats circulating in the bloodstream for longer than normal.
Doctors know that persistently high levels of harmful fats increase a person’s risk for artery-clogging heart disease (atherosclerosis), but it is not known what the importance of short term rises in harmful fats is.
This study, published in the January 2002 issue of the journal Psychophysiology(2002; 39: 80-85), assessed clearance of a fat emulsion administered into the veins of 70 healthy men and women. The emulsion was rich in the fats called triglycerides. Clearance was assessed both during a stress session and a non-stress session.
During the stress session the participants had to carry out a series of tasks, including number subtraction and tracing objects viewed in a mirror, continuously, for 40 minutes. During the non-stress session the people rested quietly for 40 minutes. Blood samples were taken at 5-minute intervals in both the stress and non-stress sessions.
The tasks used in the stress session are standard laboratory tests that have been shown to cause increases in blood pressure and heart rate when carried out for extended time periods.
The results from the blood samples showed that the harmful triglycerides were cleared significantly faster from the bloodstream in the non-stress rest session than in the stress session.
These results may well mean that the fats from the bag of chips or chocolate cake you eat when you’re stressed will hang around in your bloodstream for longer than they would under unstressful circumstances.
Triglycerides are one of 2 main types of fat found in the bloodstream. The other type is cholesterol. When you have a blood cholesterol test, the laboratory can measure triglyceride levels as well.
It is sensible for all adults to have their cholesterol and triglyceride levels measured at least once. If the levels are low, and you don't change your diet and exercise pattern, it may not be necessary to have them checked again for some time. But if the levels are abnormally high, your doctor may need to advise you about cholesterol management.
The National Heart Foundation recommends that all adults aged 45 and older, or those who are younger than 45 and have risk factors for heart disease, such as diabetes, should have regular blood tests to check their cholesterol and triglyceride levels.
Last Reviewed: 18 February 2002
- 1. Stoney CM, West SG, Hughes JW, Lentino LM, Finney ML, Falko J, Bausserman L. Acute psychological stress reduces plasma triglyceride clearance. Psychophysiology 2002 Jan; 39(1): 80-5.
