Stanol-enriched diets boost cholesterol lowering of statins
maximum-dose statins has clinical relevance for cardiovascular
health, reports research from Holland into a population of patients
not previously studied for such dietary interventions.
"Our study clearly suggests that there may be an additive effect of clinical relevance on top of statins. In mildly hypercholesterolemic subjects with a mildly elevated risk of atherosclerosis, stanols should be part of the lifestyle intervention," lead author Manuel Castro Cabezas, MD, PhD, told NutraIngredients.com.
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.
Numerous clinical trials in controlled settings have reported 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, but whether plant stanol interventions in people already getting optimal statin treatments could impact cholesterol levels has not been studied.
The new research, published in the October issue of the Journal of the American Dietetic Association (Vol. 106, pp. 1564-1569), recruited 20 hypercholesterolaemic patients at the outpatient clinic of the Department of Vascular Medicine of the University Medical Center Utrecht. All the patients had been receiving the optimal daily dose of statins (atorvastatin or simvastatin, 80 mg) without change for six months.
The single-blind, randomised study assigned subjects to receive either a plant stanol-enriched margarine (Benecol, Johnson & Johnson) or a comparable stanol-free margarine (Becel, Unilever) for six weeks. The fat content of each margarine was the same (62 per cent).
The subjects' daily intake of the margarines was between 30 and 35 grams, providing the stanol group with the recommended daily stanol intake of three grams.
The researchers report that the stanol group had lower plasma cholesterol and LDL cholesterol at the end of the intervention period with reductions of 9.9 and 15.6 per cent, respectively. Levels of the apolipoprotein B (ApoB) also decreased by 10.8 per cent.
ApoB is the main apolipoprotein of LDL cholesterol and is responsible for the transport of cholesterol to tissues. In high concentrations it has been linked to plaque formation in the blood vessels, although the mechanism behind this is not clear.
The control group (people eating stanol-free margarine and taking high-dose statins) only had reductions in LDL-cholesterol levels (7.7 per cent) and not total cholesterol levels. Plasma ApoB levels also fell 6.8 per cent.
No difference in triglyceride levels was observed, and the researchers state that the differences between the LDL-cholesterol and ApoB levels was not statistically significant between the groups.
"Intensive dietary intervention with addition of plant stanols results in clinically relevant reduction of low-density lipoprotein cholesterol in patients optimally treated with statins, compared with similar patients on statins receiving only standard care," concluded the researchers from the University Medical Centre Utrecht, and the University of Wageningen.
The study has several limitations, most notably the small sample size and short-follow up. Also, the sample population may not be representative since the many patients reportedly refused participation due to study duration and the need for hospital visits, noted Dr. Castro Cabezas.
While the researchers recommended that physicians consider advising patients of such "lifestyle interventions", Dr. Castro Cabezas told this website that many doctors do not sufficiently propose stanol-enriched foods to their patients.
"[This is] probably due to the lack of knowledge in this field by doctors. Most doctors are not very much used to 'prescribing' lifestyle interventions or dietary advice, probably due to the 'teaching gap' concerning these issues at the University," he said.
"Close collaboration with the department of nutrition in the hospital is a very important issue when advising these lifestyle changes and especially addition of stanol containing products that sometimes may also contain calories," said Dr. Castro Cabezas.
"The use of these products should be monitored and followed up by a dietitian/nutritionist."
The study has been welcomed by Ingmir Wester, vice president regulatory and scientific affairs at Raisio and inventor of the Benecol ingredient, who told NutraIngredients.com that the study added to previous research reporting the benefits of combining Benecol and statins.
Wester said that he agreed with the researchers' call for long-term studies with more subjects, but said that this research was "in the pipeline" with independent studies in the process of being published.