A phytosterol-enriched spread improves the lipid profile of subjects with type 2 diabetes mellitus—a randomized controlled trial under free-living conditions

BACKGROUND: Phytosterol-enriched margarines are known to significantly lower total and LDL cholesterol, but little is known about the effect of such margarines in subjects with type 2 diabetes.

AIM OF THE STUDY: Investigation of the effect of a phytosterol-enriched spread in subjects with type 2 diabetes mellitus on serum lipids, Hb(A1c), and blood glucose under free-living conditions.

METHODS: Randomized, placebo-controlled, double-blind clinical trial in two parallel groups over 12 weeks; 85 type 2 diabetic patients with serum LDL cholesterol levels >/= 3.60 mmol/l and without hypolipidemic medication were included in the study. Participants consumed 2 x 10 g of spread with or without 8 % phytosterol-esters daily. Fasting blood samples were analyzed at 0, 4, 8, and 12 weeks.

RESULTS: After 4 weeks, total and LDL cholesterol were significantly reduced in the phytosterol group by 5.2 % and 6.8 %, respectively, compared to baseline (p < 0.05). After 8 and 12 weeks, these reductions became smaller and were not significant any more compared to baseline or between the groups, but a repeated measurement analysis demonstrated a significant difference for both variables between the two groups (each p < 0.05). HDL cholesterol was significantly increased in the phytosterol group compared to the placebo group after 8 and 12 weeks, but there was no overall difference in the repeated measurement analysis between the two groups. In the phytosterol group, there was a small reduction in Hb(A1c) compared to the control group which was only significant after 4 weeks.

CONCLUSIONS: This clinical study shows that a phytosterol-enriched spread is effective in lowering total and LDL cholesterol in subjects with type 2 diabetes but also illustrates the difficult maintenance under free-living conditions over time. Although this effect is modest, it may contribute to decreasing the elevated risk of cardiovascular disease in type 2 diabetes.