|Not all protein supplements are created equal. And this goes for whey supplements from different countries, too.|
Shocked? I'd hope not. I mean, you don't even know what the scientists base their conclusion on - right? So before we even try to put things into perspective, it would be wise to take a look a the design of this in vitro study.
While the researchers from the Universidade Federal de Rio de Jaieiro acknowledge that whey protein, in general, is an effective adjunct to the diet of strength and even endurance athletes, they insist that there is too little "information regarding the WP supplement protein quality" and thus set out to "to investigate the protein quality of commercial WP supplements produced by U.S. and Brazilian companies based on in vitro digestibility (IVPD) assay, EAA, AAS and [protein digestibility-corrected amino acid] PDCAAS." (Almeida. 2014)
To this ends, the researchers acquired fifteen samples of whey protein (WP), soy protein, and caseinate isolate powder from a commercial retailer specialized on nutritional supplements. The supplements had been manufactured at different countries - eight from USA companies (WP-USA), and seven from Brazilian companies (WP-BRA). The supplements manufactured with soy protein and caseinate isolate powder were used as references in a study that yielded quite surprising results.
|Figure 1: Essential amino acid composition of two commercial whey protein supplements (Almeida. 2014).|
|Figure 2: Relative loss (%) of amino acids during simulated (in vitro) digestion in US and Brazilian whey (Almeida. 2014).|
If you consume twice the WHO suggestions for athletes, you are thus not at a risk of being deficient in any of the EAAs, but could maybe optimize the ratio of the individual amino acids by not covering your protein needs from a single protein source.
As you can easily see in Figure 1, though, this was not the case in the study at hand. Plus: There were also significant differences in the protein digestibility-corrected amino acid composition, i.e. the marker of whether or not the content of a certain essential amino acid per gram of protein was sufficient or not. In that, values <1.0 indicate there is too little of this amino acid in the mix.
|Figure 3: Amino acid score and protein
digestibility-corrected amino acid composition for the commercial|
US and Brazilian whey supplements (Almeida. 2014).
- Almeida, Cristine Couto, et al. "In vitro digestibility of commercial whey protein supplements." LWT-Food Science and Technology (2014).
- AOAC International, and George W. Latimer. Official Methods of analysis of AOAC International. AOAC International, 2012.
- Hsu, H. W., et al. "A multienzyme technique for estimating protein digestibility." Journal of Food Science 42.5 (1977): 1269-1273.
- WHO. "Protein and amino acid requirements in human nutrition." World Health Organization technical report series 935 (2007):