Whey Protein & Sialic Acid

Editor(s): Myths & Facts Series Vol.2 , 2012


NNI believes that science is a medium for better nutrition. With the aim to keep medical professionals up to date with latest technology and innovations, this issue focuses on the myths and facts about Whey Proteins and Sialic Acid. Numerous myths regarding certain nutrients and the evidences of their efficacy and safety prevail amongst the expectant mothers and their families. The myths and facts series of Nestle Nutrition Institute’s publications include scientific evidences which clarify such myths. The various myths around these two have been negated with the help of actual fact and reasoning, and has been substantiated logically and scientifically.

Currently, a lot of myths exist regarding certain nutrient and the evidence of their efficacy and safety in adult and paediatric population. In order to provide the current evidence on some of the nutrients, “Myths and Facts” series was introduced by NNI. Through this initiative, they have tried to provide the current evidence on nutrients that would help us to form an opinion that is based on science. This issue is focussed on “Whey Proteins and Sialic Acid”.

Let’s look at a myth like quality of protein is same in human milk and bovine milk but the fact is that the protein composition of human milk is different from bovine milk. In addition to its lower total protein content, human milk has high concentration of whey proteins (the whey content is approximately 70% of total protein content in early lactation) than bovine milk (20% of total protein). Another myth is that the composition of alpha-lactalbumin is same in human and bovine milk though the fact is that Alpha-lactalbumin is rich in essential amino acids and is the most prominent component in human milk. It comprises approximately 20% to 25% of the total protein content (2–3 g of the 9 –11 g total protein/L), whereas only 2%–3% of bovine milk protein is alpha-lactalbumin. One myth is that Whey proteins do not have any nutritional benefit but the fact is Whey proteins have been reported to have utility in many different applications ranging from effects on bone, muscle, blood, brain, pancreas, immune, cancer, infection, metabolism, wound healing, learning, and aging. Infant formulas contain whey protein in varying proportions as per the age of the child. Usually the starter formulas have higher whey content than the follow up formulas.

A myth about Sialic acid is that it is present only in human beings but the fact says that Sialic acid is found in all vertebrates (Mammalia, Aves, Reptilia, Amphibia, and Pisces) but not generally found in plants, prokaryotes, or invertebrates. One myth says Sialic acid is present only in brain but the fact is that Sialic acid is present in essentially all tissues, but the majority is present in gangliosides (65%) of mammalian central nervous system and the rest as glycoproteins (32%) free Sialic acid (3%).4 The gangliosides are distributed within the human body in large visceral organs such as liver, lung, and spleen and intestinal mucosa; the concentration being highest in brain grey matter.