Lipids and cardiovascular disease risks with a focus on dairy foods

Cardiovascular diseases (CVD) remain a major cause of death and morbidity worldwide and dietary guidelines aim to restrict the intake of saturated fatty acids (SFA) as they have been regarded as an important risk factor for CVD due to of their association with increased blood cholesterol. Since dairy foods are often the major contributors of dietary SFA, there have been guidelines to reduce consumption of these foods. However it is now generally accepted that the effects of dietary SFA are not simple and can be influenced by their source and food matrices. Also the effect of reducing SFA intake is best interpreted by a knowledge of what replaces them. Reduced CVD risk has been associated with replacement of SFA with cis-polyunsaturated fatty acids (cis-PUFA) and/or cis-monounsaturated fatty acids (cis-MUFA), with replacement by carbohydrate leading to no reduction or even increased CVD risk. Most studies on the effect of diet/food on CVD risk have used total cholesterol (TC) and/or low density lipoprotein cholesterol (LDL-C) in blood as the marker(s) of risk. However, because of potentially attenuating effects of dairy foods (e.g. effect of protein on blood lipids and blood pressure; food matrix effects on fat bioavailability) a wider range of markers is needed to more fully evaluate disease risk. Nevertheless, whilst prospective evidence shows no increase in CVD risk from high dairy consumption, it is still uncertain whether replacing a proportion of SFA in dairy fat with cis-MUFA will consistently lead to reduced CVD risk. The relatively few randomised controlled trials (RCTs) that have examined this using TC and/or LDL-C as risk markers give an indication of benefit and the results of a recent RCT give stronger support to this.