Of the 20 or so amino acids used by the human body, nine are considered indispensable. That means those amino acids must come from the foods we eat. Scientists and dietitians used this principle to develop a rating system for food's ability to deliver life-building protein to people.
Until now, scientists haven’t been able to differentiate between amino acids absorbed by the body and those consumed by bacteria living in the intestine. Dubbed the Protein Digestibility Corrected Amino Acid Score (PDCAAS), that system treated whole milk and whey proteins the same as soy isolate. Further, it rated beef’s protein as even lower in quality than soy while overestimating foods such as chickpeas and kidney beans.
Fortunately, the power of science has unlocked a better discovery system. Researchers now can accurately measure precise amino acid digestion rates versus simply quantifying crude protein levels. The new measuring standard called Digestible Indispensable Amino Acid Score, or DIAAS for short, was developed by Riddet Institute researchers at New Zealand’s Massey University. Since its creation, the DIAAS system has started to make its way through the FAO and has received favorable reviews based on its ability to measure amino acid quality actually available for human growth.
That is welcomed news for those providing animal-based proteins . . . of which dairy leads the pack. On the new protein measurement system, whole milk moved from a score of 1 to 1.32; whey protein isolate, 1 to 1.25; whey protein concentrate, from 1 to 1.1; and beef from 0.92 to 1.1. On the plant side, soy isolate held its own at 1, chickpeas dropped from 0.78 to 0.66, and kidney beans fell from 0.68 to 0.51. Those reductions took place because bacteria, not the human body, are consuming some of the plant protein.
While the main goal of scientists all along has been to accurately measure amino acids’ ability to build a healthier and stronger human body, dairy also comes out a winner. Its superior protein does a body good. Pass it on.