Abstract:
Cow’s milk proteins and related bioactive peptides are purported to have a wide range of effects on human health across the life span. Casein and whey protein have both been proposed to play a role in the prevention of chronic age-related conditions such as adverse metabolic health and type 2 diabetes, muscle wasting and sarcopenia, atherosclerosis, hypertension and cardiovascular disease risk, as well as bone health and osteoporosis. Epidemiological studies have shown regular dairy consumption to be associated with decreased prevalence of cardiometabolic risk, an outcome of improved metabolic health, while intervention studies have shown milk proteins to promote postprandial insulin secretion and glycemic control, and under some conditions improve postprandial lipemia and hypertension. The branched-chain amino acids of dairy protein also promote muscle anabolism, important for the maintenance of muscle mass and mobility during aging and, in our current epidemic of obesity, for the maintenance of lean body mass during energy restriction and weight loss. Dietary protein is known to suppress satiety and food intake, and if consumed from a dairy source may support preferential loss of fat rather than lean mass during weight loss. Milk proteins may also be beneficial for bone health during aging. In addition, milk proteins are important for maternal and infant nutrition, with protein playing a major role in growth and development during early life. While public health recommendations for breastfeeding underpin nutrition in young infants, commercial infant formulas are required for mothers unable to breastfeed long term, and formulas containing cow’s milk protein aim to optimize infant health. In this chapter we review the evidence for the potential health benefits of milk proteins, based on human clinical trials, with a particular focus on metabolic health.