Abstract:
Milk is a nearly complete food having all most all the nutrients required by the body except that it lacks fibre and has limited iron. Milk and milk products are playing very important role in human nutrition since ancient times. They are also known to confer several health benefits apart from prevention of several diseases. Dairy based foods can be a very good tool to achieve United Nations SDG-2, as they offer a great potential to tackle the problem of malnutrition and food security, especially in developing countries of Asia, Latin America and Africa. Milk is a natural lacteal secretion and is a treasure of easily assimilable nutrients. Its unique nutrients and their presence in a particular matrix, make milk a super food.
Milk fat has high content of short chain fatty acids (SCFAs) and medium chain fatty acids (MCFAs), which exhibit various regulatory and signalling functions. The most characteristic fatty acids for bovine milk fat are conjugated linoleic acid (CLA) and butyrate. CLA is known to have several therapeutic benefits. Docosahexaenoic acid (DHA) is an omega-3 fatty acid essential for brain development during pregnancy and early childhood. In milk, fat globules are covered with membrane (MFGM). The MFGM components such as sphingomyelin and gangliosides, improves the cognitive score of infants apart from several nutraceutical properties. Milk contains 3 to 4% protein, which comprise of 80% casein and 20% whey proteins, mainly α-lactalbumin and β-lactoglobulin. Milk proteins contain all nine essential amino acids, while most plant proteins are incomplete, as they are missing at least one or more of the essential amino acids. Hence dairy in diet is essential for nutritional security of large lacto-vegetarian population. Whey proteins of milk, contain branched chain amino acids which are very useful for building muscle. Milk proteins produce biologically active peptides which are proved to have antioxidant, anticarcinogenic, antihypertensive, immunostimulatory, antimicrobial and other properties. It contains high tryptophan content which is precursor of serotonin, important for sleep and control of anxiety. Milk proteins possess the greatest potential to provide satiety signals.
Lactose is a unique sugar present only in milk, which has glucose and galactose. Galactose is required in synthesis of gangliosides which are component of glycolipid. This glycolipid is essential in formation of brain tissues. Lactose also increases absorption of minerals like calcium, magnesium & zinc. Lactose has Lower glycemic index (46) as compared to sucrose (66). Lactose and lactulose have conditional prebiotic effect to support health gut flora.
Milk is an important source of micronutrients including thiamin, vitamin B6 and zinc that work in concert with other B vitamins like pantothenic acid to help convert your food into energy and magnesium, which also helps to build strong bones. Plus, milk has selenium, which works with vitamin A to help maintain a healthy immune system. The major milk mineral is Calcium, which is more easily absorbed than any other source. Ca and P in the diet helps build and maintain strong bones. Lactose and Vitamin D play a role in enhancing calcium absorption. Thus, milk is a capsule of essential, available and useful nutrients for the body.