Disclosed is the use of a composition comprising a combination of diacylglycerol(s) (DAG), mainly 1,3-diacylglycerol(s), and phytosterol and/or phytostanol ester(s) (PSE) dissolved or dispersed in edible oil and/or edible fat, particularly olive, canola and fish oil, in the manufacture of nutritional supplements and orally administrable pharmaceutical preparations which are capable of reducing blood levels of both cholesterol and triglycerides and/or for lowering serum, serum LDL and macrophage oxidation levels, inhibiting the formation of foam cells and/or preventing the deleterious effects generated by lipid-induced oxidative stress. In addition, the composition of the invention, as well as the pharmaceutical preparations thereof, are suitable for the treatment and prevention of conditions related to atherosclerosis, such as cardiovascular disease (CVD), coronary heart disease (CHD) and diabetes mellitus.