"Both consuming plant sterols and exercising have been shown to affect blood cholesterol levels on their own," said senior author McGill Professor of dietetics and nutrition, Peter Jones. "Our research is the first to look at the complementary combined effects of these therapies."
Seventy-four non-active individuals between the ages of 40 and 70 were recruited for the study. They were placed into the following four different intervention groups: combination (consumed margarine containing plant sterols and exercised), exercise (consumed plant-sterol -free margarine and exercised), sterol only (consumed margarine containing plant sterols and did not exercise) and control (consumed plant-sterol free margarine and did not exercise). Exercise involved using stair-stepping machines and stationary bicycles three times a week. Margarine was consumed four times a day. This regimen was continued for eight weeks, blood samples were taken and lipid analysis was performed.
"In comparison with plant sterols or exercise alone, the combination of plant sterols and exercise yielded the most beneficial change in the volunteer's cholesterol and lipid levels," said lead author and McGill doctoral student, Krista Varady. "This combination therapy favourably altered their lipid profiles by decreasing total cholesterol, low-density lipoprotein (LDL) cholesterol, and triacylglycerol levels and by increasing high-density lipoprotein (HDL) cholesterol levels."
"These findings suggest that combination therapy may improve the cholesterol and lipid levels in previously sedentary adults who have high cholesterol. Furthermore this therapy may reduce the risk of coronary artery disease for these individuals."
Jones added that there were other benefits associated with the exercise program. "Our volunteers were typically inactive. In addition to the altered cholesterol levels, the increased physical activity contributed to loss of weight and improved motivation. Long term exercise can also reduce blood pressure and reduce the risk of other health complications."
"These findings on the combination of plant sterols - which are also naturally present in nuts, seeds, legumes, vegetable oils, and other plant sources - and exercise are very interesting," says Dr. Jacques Genest, spokesperson for the Heart and Stroke Foundation. "The Heart and Stroke Foundation supports this research to find ways to reduce high blood cholesterol, a significant risk factor for heart disease and stroke."
This research was supported by funding from the Heart and Stroke Foundation.
About McGill University
McGill University is Canada's leading research-intensive university and has earned an international reputation for scholarly achievement and scientific discovery. Founded in 1821, McGill has 21 faculties and professional schools which offer more than 300 programs from the undergraduate to the doctoral level. McGill attracts renowned professors and researchers from around the world and top students from more than 150 countries, creating one of the most dynamic and diverse education environments in North America. There are approximately 23,000 undergraduate students and 7,000 graduate students. It is one of two Canadian members of the American Association of Universities. McGill's two campuses are located in Montreal, Canada.
About the Heart and Stroke Foundation
The Heart and Stroke Foundation (www.heartandstroke.ca) is a leading funder of heart and stroke research in Canada. The Foundation's mission is to improve the health of Canadians by preventing and reducing disability and death from heart disease and stroke through research, health promotion and advocacy.
Journal
American Journal of Clinical Nutrition