A team from University College London, UK has found that stress appears to raise
cholesterol levels over the long-term in some people, potentially increasing the
risk of heart disease.
Previous studies had established that stress is linked to increased heart rate
and weakened immune systems.
The research team gave people 199 people stress tests and cholesterol tests
three years apart. Some of the participants showed large increases in
cholesterol levels even in the short-term, while others show very little
response.
Lead researcher Professor Andrew Steptoe said:
"The cholesterol responses that we measured in the lab probably reflect the way
people react to challenges in everyday life as well.
So the larger responders to stress tasks will be large responders to emotional
situations in their lives and will have a greater chance of raised cholesterol -
a major risk factor for heart and circulatory disease."
The participants were followed up three years later.
Cholesterol levels in all had gone up. However, those people whose cholesterol
had risen the most following the initial tests showed substantially greater
rises.
Levels of LDL, or "bad" cholesterol were three times as likely to be at
potentially harmful levels in this group compared with those who registered the
smallest cholesterol rise after the initial tests.
This was after factors such as baseline cholesterol levels, age, gender, smoking
and alcohol consumption were taken into consideration.
The researchers cited several possible reasons to explain this increase in
cholesterol level with stress.
1. It might be possible that stress encourages the body to produce more energy
in the form of fatty acids and glucose. These substances require the liver to
produce and secrete more LDL cholesterol so that they can be transported to the
other tissues of the body.
2. Stress interferes with the body's ability to rid itself of excess
cholesterol.
3. Stress triggers a number of inflammatory processes which also increase
cholesterol production.
Dr Charmaine Griffiths, of the British Heart Foundation said: "We know that
stress has a link to heart disease.
"The research suggests that this may be due to stress causing long-term
increases in cholesterol in some people.
"We can't yet single out those whose bodies respond strongly to stress, but
everyone can cut their chances of developing high cholesterol through a healthy
diet and regular exercise."