Public health guidelines targeting cardiovascular disease (CVD) and type 2 diabetes (T2DM) have focused on cutting saturated fat from our diets, with milk and dairy products being singled out as sources of saturated fat.
It is hard to ignore recent controversies on the role of saturated fat in cardiometabolic disease.
Although our public health guidelines recommend cutting saturated fat to target CVD and T2DM in the population, several recent meta-analyses have indicated saturated fat had no association with coronary outcomes.
Furthermore, a new 12-week intervention study found a high-saturated fat diet raised ‘good’ cholesterol as well as ‘bad’ forms, when compared to a low-fat high carbohydrate diet among obese men.
Saturated fat is no longer considered a single entity, but a diverse family of fatty acids with a variety of effects on human metabolism. Recent work from Cambridge shows two saturated fatty acids unique to dairy foods are associated with reduced risk of coronary outcomes and developing T2DM.
This association should not be overplayed, but it flags up a potential mechanism by which dairy foods may have neutral or protective effects and this is a research area ripe for further investigation.
It is worth noting an expert Fats Working Group will report to Public Health England in December this year on the evidence supporting saturated fat guidelines in the UK.
Milk and dairy foods contain an array of important nutrients, but in the public health crusade against saturated fat they may have been unfairly targeted.
Meta-analyses have shown milk and dairy have a weak protective or neutral effect on the risk of CVD and body fatness. A large recent study from Harvard showed milk, cheese and total dairy intake had no effect on risk of developing T2DM, but consumption of yoghurt over several decades was protective.
The base of evidence, much wider than presented here, is so consistent a recent review by leading academics in the UK strongly cautioned against public health measures which try to reduce or eliminate milk and dairy from the diet for cardiometabolic health.
The world of saturated fat and cardiometabolic disease has been rocked in recent years by research questioning the science on which our public health guidelines have been based, powered in many instances by the strong statistical approach of meta-analysis.
Furthermore, advances in human nutrition research strongly indicate there is something special about milk and dairy.
Fat content and composition, micronutrients such as calcium, proteins such as whey and casein and the physical matrix of dairy foods are all under investigation for mediating neutral or protective effects on CVD and T2DM.