• Question: Have you come to any conclusions about the best type of protein yet?

    Asked by steveb to Alex on 12 Jun 2011.
    • Photo: Alex Munro

      Alex Munro answered on 12 Jun 2011:

      Protein ‘quality’ is a very interesting & complicated topic! Many methods of determining quality have been devised: biological value, net protein utilisation, the protein efficiency ratio…

      The method adopted by the World Health Organisation is the Protein Digestibility Corrected Amino Acid Score (or PDCAAS) – even the name is complicated!

      The building blocks of protein are amino acids, and the body needs amino acids to make all sorts of things, including muscle, enzymes and hormones, e.g. adrenaline is synthesised from tyrosine

      The body can make some of these amino acids, but some it can’t and these have to be provided in the diet – they are called essential amino acids (EAAs) for this reason. There are 9 EAAs: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. A protein containing all 9 EAAs would be a ‘good quality’ protein, whereas one that is missing some of them, would not…

      According to the PDCAAS the two milk proteins (casein & why), egg white and soy protein have the highest score (1.00), beef is close after at 0.92…