Stress shown to raise bad cholesterol levels

British scientists have found that cholesterol levels in healthy adults can be raised by stress.

Experts were already aware that stress can increase heart rate and signs of inflammation, and weaken the immune system, but until now it was not clear whether stress could directly influence levels of cholesterol in the blood.

The new findings, by researchers at University College London suggest that, for some people at least, it can.

In the study funded by the British Heart Foundation, the studied 199 healthy middle-aged men and women.

Each volunteer was asked to complete two moderately stressful tasks on a computer, which involved matching colours to words and tracing a star seen in a mirror image.

After the stress tasks, various aspects of heart function and blood circulation were analysed.

Three years later, every participant was given a cholesterol test, and as expected over the passage of time, in each case levels of cholesterol had gone up.

However it seems that the biggest increases were seen in the individuals who had experienced the most initial stress during the computer task experiments.

According to the researchers the people in the top third of "stress responders" were three times more likely to have high levels of the "bad" cholesterol known as low density lipoprotein than those in the bottom third.

The study is published in the journal Health Psychology.