Background: Plant sterols and exercise favourably alter lipid profiles in a way that protect against future coronary heart disease (CHD). However, their effects on other indicators of CHD risk, such as LDL particle size, still need further clarification.
Objective: This study examined the effect of plant sterols, exercise, and the combination of plant sterols and exercise, on LDL particle size and distribution in previously sedentary, hypercholesterolemic adults.
Design: In an 8-week, placebo-controlled, parallel-arm clinical trial, 84 subjects were randomized to one of four intervention groups: (1) combination of sterols and exercise, (2) exercise, (3) sterol, or (4) control.
Results: Exercise significantly (P < 0.05) reduced post-treatment LDL peak particle size from 255 to 253 A. Additionally, exercise significantly (P < 0.05) decreased the proportion of large LDL particles within plasma. Sterol supplementation significantly (P < 0.05) decreased the estimated cholesterol concentrations within small, medium, and large LDL particles by 13.4, 13.5, and 14.4%, respectively, yet had no effect on the distribution of cholesterol among various LDL particle sizes. Furthermore, decreased body weight post-training was associated with increased cholesterol in small LDL particles (r = -0.52, P < 0.0001). Decrease in body fat percent (BF%) post-training was associated with increased cholesterol concentrations in small LDL particles (r = -0.29, P < 0.01).
Conclusion: On the basis of modulating LDL electrophoretic characteristics, the present study demonstrates that plant sterols have no effect on CHD risk, while short-term exercise may potentially increase CHD risk by decreasing LDL peak particle size.
Sponsorship: This study was sponsored by The Heart and Stroke Foundation of Canada.