Finnish study supports sterols' safety
safe, suggests a new study from Finland that adds to a growing body
of evidence supporting the ingredients.
In a study with 71 participants with moderately high cholesterol levels (hypercholesterolemia), researchers from the University of Helsinki report that consumption of plant did not cause any serious adverse effects.
The findings, published online in the European Journal of Clinical Nutrition , did report a small decrease in blood levels of vitamin E (alpha-tocopherol), but these changes were not observed once the researchers accounted for decreases in levels of LDL ('bad') cholesterol.
"Fifteen-week consumption of natural non-esterified plant sterol-enriched food does not cause any serious adverse effects during such a period," wrote the researchers, led by Professor Matti Tikkanen from Helsinki University Central Hospital.
"However, serum alpha-tocopherol levels were somewhat reduced in the sterol group suggesting that long-term effects of plant sterols on serum fat-soluble vitamin concentrations should be further explored, especially in relation to very low-fat diets."
Numerous clinical trials carried out in controlled settings led researchers to report that daily consumption of 1.5 to 3 grams of phytosterols/-stanols can reduce total cholesterol levels by eight to 17 per cent, representing a significant reduction in the risk of cardiovascular disease.
However, some concerns have been raised by certain EU Member States regarding over consumption of phytosterols/-stanols.
The new study appears to show that such concerns may be unfounded.
The study Tikkanen and co-workers recruits 52 women and 19 men with moderate hypercholesterolemia and randomly assigned them to receive food items enriched with 1.25, 2.5 and 5.0 g per day of plant sterols during for three successive five-week periods, respectively.
A fourth group was assigned to consume the same products without sterol enrichment (placebo group).
The researchers report two significant findings.
Firstly, blood levels of sitosterol increased from 2.84 to 5.35 milligrams per litre, while plant sterol levels never exceeded 0.6 per cent of total blood sterols.
Secondly, blood levels of alpha-tocopherol by 10 per cent in the group receiving the sterol-enriched food.
However, "the between-group difference disappeared after adjusting for the change in the carrier (LDL cholesterol)," they stated.
Supporting science Previously, post-launch monitoring studies of the functional foods have reported that phytosterol and stanol enriched margarines can stabilises cholesterol levels in a free-living population.
A study from the Netherlands reported that the ratio of total cholesterol to HDL cholesterol, reported to be the most specific lipid risk factor for CVD, decreased for the users of plant phytosterol- and stanol-enriched margarines by 0.29 millimoles per litre after five years ( Food and Chemical Toxicology , Vol. 44, pp. 1682-1688).
On the other hand, research from France reported that people in France at a high risk of cardiovascular disease are not consuming phytosterol-enriched margarine ( Nutrition, Metabolism and Cardiovascular Diseases , doi:10.1016/j.numecd.2006.07.012).
High cholesterol levels, hypercholesterolaemia, have a long association with many diseases, particularly cardiovascular disease (CVD), the cause of almost 50 per cent of deaths in Europe, and reported to cost the EU economy an estimated €169bn ($202bn) per year.
Source: European Journal of Clinical Nutrition Published online ahead of print 13 February 2008; doi: 10.1038/ejcn.2008.11 "Safety assessment of common foods enriched with natural nonesterified plant sterols" Authors: J. Tuomilehto, M.J. Tikkanen, P. Hogstrom, S. Keinanen-Kiukaanniemi, V. Piironen, J. Toivo, J.T. Salonen, K. Nyyssonen, U.-H. Stenman, H. Alfthan, H. Karppanen
