The meta-analysis, funded by the Raisio Group and published in Prostaglandins, Leukotrienes and Essential Fatty Acids, aimed to determine differences in LDL-cholesterol lowering efficacy of plant stanols and plant sterols from different daily intakes; finding that stanols may reduce levels of LDL-cholesterol by more than twice that of sterols in doses over that of 2 grams per day (g/day).
“The maximal LDL-cholesterol reduction of 16.4 percent for plant stanols is significantly greater than the 8.3 percent maximal LDL-cholesterol reduction noted for plant sterols, and also is an effect that is almost 2-fold greater than that achieved at an intake of 2g/day plant stanols,” said the authors, led by Dr Kathy Musa-Veloso, Associate Director of the Food & Nutrition Group at Cantox Health Sciences International, Canada.
“Our results suggest that across a continuous dose range, LDL-cholesterol reductions are dose-dependent for plant stanols but not for plant sterols,” they added.
“Several scientific and authoritative bodies recommend the daily consumption of 2g plant stanols or plant sterols, expressed as free plant stanol or plant sterol equivalents, for improving blood lipid levels,” said the authors.
However, the comparative efficacy of plant stanols versus plant sterols in reducing low-density lipoprotein cholesterol (LDL-CH) levels may still be unknown, they explained.
Dr Musa-Veloso and colleagues referred to previous meta-analysis’, noting that although many shown no significant differences between plant stanols and plant sterols for LDL-cholesterol reduction, many also failed to accurately distinguish between the two.
“A notable limitation in these early evaluations is that the efficacies of plant stanols and plant sterols across a range of intakes were assumed to be comparable, resulting in the amalgamation of study results, irrespective of the intervention,” they said
They said that as such, it is unclear whether greater reductions in LDL-cholesterol can be achieved with higher daily intakes of plant stanols or plant sterols, or whether plant stanols and plant sterols have similar LDL-cholesterol lowering efficacies at higher intake levels.
The new meta-analysis determined whether there are differences between plant stanols and plant sterols in their LDL-CH lowering effects over a range of intakes.
Musa-Veloso and co-workers identified 113 publications and one unpublished study report, representing 182 data sets (strata), which met the inclusion/exclusion criteria.
They noted that the number of strata in the new meta-analysis represents an increase of approximately 43 percent on the data included in the last comprehensive review (Demonty et al – J. Nutr. Volume 139)
The inclusion of the new data led researchers to find the maximal LDL-cholesterol reduction achievable with plant stanols “is approximately two-fold greater than that achievable with plant sterols.”
They explained that the maximal LDL-cholesterol reductions for plant stanols and plant stanol ester (16.4 and 17.1 percent, respectively) were found to be significantly greater than the maximal LDL-cholesterol reductions for plant sterols and plant sterol ester (8.3 and 8.4 percent).
The authors noted the “consistent linear relationship between reductions in LDL-cholesterol and reduced risk of coronary events,” adding that evidence shows for every one percent reduction in LDL-cholesterol, there is a 1-2 percent decrease in the risk of coronary heart disease.
“Thus, larger LDL-cholesterol reductions, as dose-dependently achievable with intakes of plant stanols in excess of the currently recommended 2 g/day dose, may have clinically significant implications with respect to reducing the risk of CHD at the population level,” said Musa-Veloso.
Both the European Food Safety Authority and the US Food and Drug Administration have backed the cholesterol lowering properties of stanols and sterols, however neither have differentiated between the two.
EFSA’s opinion, now EU law, states, “that for an intake of 1.5 - 2.4 g/d an average reduction of between 7 and 10.5% can be expected.”
Its opinion can be found here.
Source: Prostaglandins, Leukotrienes and Essential Fatty Acids
Published online ahead of print, doi: 10.1016/j.plefa.2011.02.001
“A comparison of the LDL- cholesterol lowering efficacy of plant stanols and plant sterols over a continuous dose range: Results of a meta-analysis of randomized, placebo-controlled trials”
Authors: K. Musa-Veloso, T.H. Poon, J.A. Elliot, C. Chung