[Comparison of the effect of a probiotic yoghurt and ordinary yoghurt on serum cholesterol levels in subjects with mild to moderate hypercholesterolemia]

ABSTRACT

Cardiovascular diseases are the first cause of death in Iran and hypercholesterolemia is one of the most important risk factors. This problem could be partially managed by dietary modifications such as supplementation of diet with dairy products and probiotic bacteria. The aim of this study was to comprise the effect of consuming a probiotic yoghurt and ordinary yoghurt on serum cholesterol levels in mild to moderate hypercholesterolemia. This randomized cross-over trial was conducted on 14 healthy subjects aged 40-65 years with total serum cholesterol 200-300 mg/dl. We asked the subjects to avoid consumption of yoghurt for a two-week pre-study period and add 300 g/day of milk to their diet. Then they were randomly allocated to 2 groups to receive either 300 g of ordinary yoghurt [fermented with S.thermophilus and L.bulgaricus] or probiotic yoghurt [fermented with a starter composed of L.acidophilus and B.lactis plus bacteria in ordinary yoghurt] for 6 weeks as substitution for milk. After a wash-out period of 7 weeks, the cross-over was made [those consuming probiotic yoghurt, changed to ordinary yoghurt and vice versa] and the study lasted for another 6 weeks. Anthropometric measurements, a 3-day dietary recall and blood lipid tests were done at the beginning [after a 2-week elimination period of yoghurt from diet] and at the end of each period. Comparison of weights, BMIs and dietary confounding factors during the period of consuming ordinary yoghurt and probiotic yoghurt, did not show any significant differences. Consumption of probiotic yoghurt in comparison with ordinary yogurt caused a significant decrease in total serum cholesterol [P=0.049]. Comparison of other blood lipid criteria did not show any significant differences between these two periods. Consumption of the yoghurt containing two probiotic bacteria, L.acidophilus and B.lactis, in comparison with ordinary yoghurt causes reduction in total serum cholesterol in mild to moderate hypercholesterolemia