It's been known for some time that exercise has a beneficial effect on blood cholesterol. A number of studies have found that exercise alters the relative proportions of different types of cholesterol - in particular, by boosting levels of 'good' (HDL) cholesterol. HDL cholesterol helps to keep arteries clear by scooping up fatty deposits as they swim by. Any effect of exercise on 'bad' cholesterol (LDL), the type that leads to build-up of fat in the blood vessels, has been more difficult to find, however

A new slant on the exercise-cholesterol story was presented at the American Heart Association's 36th Annual Conference held in March. Researchers from the Stanford Centre for Research in Disease, California, presented information on 377 men and post-menopausal women who had been diagnosed as having unhealthy cholesterol measurements. These people were divided into four groups, and prescribed one of the following: Group1) A low-fat diet, Group 2) An exercise regime, Group3) Both low-fat diet and exercise, Group 4) No changes (control group). Cholesterol levels were compared after a year

The participants who had followed the low-fat diet and the exercise regime were found to have the biggest drop in LDL cholesterol. For men, those who dieted and exercised saw their LDL cholesterol fall by an average of 20mg/dL, compared to a drop of 10.8mg/dL in men who just dieted. Dieting and exercising women cut their blood LDL cholesterol by 14.5mg/dL, compared to a drop of 7.3g/dL for those who only followed the diet

Therefore, exercise can reduce LDL cholesterol in tandem with a low-fat diet. The exercise regime used for the study included at least 45 minutes of exercise three times a week consisting of either jogging or fast walking. Previous studies have indicated that exercise needs to be carried out regularly for at least four months before it will have any impact on cholesterol levels.
('Exercise increases diet-induced drops in cholesterol', The Lancet, March 23, 1996, p819)

Janet Pidcock