A daily 4 gram dose of plant sterols in an enriched yogurt was associated with a 20 percent drop in LDL cholesterol, 16 percent drop in total cholesterol, and a 19 percent decline in triglyceride levels, despite the volunteers maintaining their habitual western-type diet, according to results of a randomized placebo-controlled study published in Nutrition, Metabolism & Cardiovascular Diseases.
“This beneficial effect was observed although the subjects were not asked to change their dietary habits,” write researchers from the Agricultural University of Athens.
“This is an important finding because it implies that phytosterols have a significant impact on the lipid profile even if the diet is still a westernized type (rich in total fat, and SFA, and low in MUFA, PUFA and dietary fiber).
“Therefore, a change in dietary habits toward a healthy dietary pattern, could have an additional benefit in the lipid profile and the risk of [cardiovascular disease],” they added.
Numerous clinical trials in controlled settings have reported that daily consumption of 1.5 to 3 grams of phytosterols/-stanols from foods can reduce total cholesterol levels by eight to 17 per cent, representing a significant reduction in the risk of cardiovascular disease.
According to a recent market research conducted by Frost & Sullivan, phytosterols are the most heart health targeted and benefited from approved health claims in many markets (as well as recently approval from the European Food Safety Authority).
The Athens-based scientists recruited 108 people with metabolic syndrome, aged between 30 and 65 and with average BMIs of 29 kg/m2. Participants were randomly assigned to receive yoghurt mini-drinks with or without added sterols (ELAIS-Unilever Hellas SA) for two months. The daily sterol dose was 4 grams, and participants continued to eat their normal diet.
Results showed a significant reduction in total cholesterol, LDL-cholesterol, triglycerides, as well as small and dense LDL (sdLDL) levels in the phytosterol group, compared with the control group. “To the best of our knowledge, this is the first study which observed a decrease in sdLDL following phytosterol supplementation,” wrote the researchers.
The Greek researchers also noted that participants in the sterol group experienced a significant decrease in levels of apolipoprotein B (Apo B) of 7 percent, compared with no change in the controls. 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.
On the other hand, no changes in levels of HDL cholesterol, apoA1, C-reactive protein, nor in the participants’ blood pressure.
“There would be however the argument if a dietary modification would mimic the effects of phytosterols on plasma lipids,” wrote the researchers. “In our study, the decrease in total and LDL-cholesterol levels was quite significant and it is greater than what the current opinion is.
“However, a change in the dietary habits toward a Mediterranean type dietary pattern (low in SFA, high in MUFA and PUFA, high in fruits and vegetables) could have an additional benefit in the lipid profile and the risk of cardiovascular diseases (CVD), since it has been found that the Mediterranean diet affects not only blood lipid levels but also endothelial function, blood pressure, and other risk factors of CVD,” they added.
84 trials agree
A review authored by researchers from Unilever R&D and Wageningen University and published in the Journal of Nutrition concluded that phytosterol-enriched foods are efficacious for reducing levels of LDL cholesterol, with no differences between stanols and sterols, or delivery in fat or non fat foods.
“For the recommended intake of two grams per day, the expected LDL-C–lowering effect of phytosterols is [about] 9 percent,” wrote the authors, led by Isabelle Demonty. “A reduction in LDL-C of about 10 percent would reduce the incidence of CHD by about 10-20 percent.
“Although no direct evidence is available yet for the ability of phytosterols to lower CHD incidence, the well-documented cholesterol-lowering effect of phytosterols is the basis for recommendations to include phytosterols into strategies to lower LDL-C concentrations,” they added.
Source: Nutrition, Metabolism & Cardiovascular Diseases
Published online ahead of print, doi:10.1016/j.numecd.2010.12.004
“Phytosterols supplementation decreases plasma small and dense LDL levels in metabolic syndrome patients on a westernized type diet”
Authors: T.E. Sialvera, G.D. Pounis, A.E. Koutelidakis, D.J. Richter, G. Yfanti, M. Kapsokefalou, G. Goumas, N. Chiotinis, E. Diamantopoulos, A. Zampelas