Whey Protein
Why liquid-fraction cheese run-off is a bad protein source
TLDR; Whey protein concentrates & isolates are synthesized by removing the fat and carbohydrates (mostly lactose) from the 20% residual whey liquid fraction after milk coagulation in the cheesemaking process. It’s weird that in the modern equilibrium many people consume perhaps 25-50% of daily protein from cheese runoff b/c the amino acid composition and structure of these powders are significantly different from meat/fish-based protein (the primary protein source in a human’s ancestral diet). Specifically, the free (not integrated in a polypeptide chain) amino acid profile of these powders may confer negative health effects. One such example is the comparatively high concentration of free glutamate/glutamic acid in hydrolyzed whey, which may actuate excitotoxicity in sufficiently high doses or in people who exhibit MSG intolerance.
It’s curious that whey concentrate and isolate protein sources have become the ‘gold-standard’ for supplementary protein. Of course, the economics make sense: just as the industrial manufacture byproduct fluoride was adopted as means to remineralize teeth via fluorapatite accretion (instead of the ad hoc manufacture of the comparatively safer calcium sodium phosphosilicates and/or hydroxyapatite, which is deserving of a separate tractate because fyi fluoride is a neurotoxin, teratogenic in medium to high doses, probably anti-androgenic, and a bad cariostatic agent given its side effect profile + constitutes a non-consensual pharmacologic intervention in much of the first world), so too is whey peptide isolation a cost-effective way of using a manufacture byproduct as a marketable health intervention.
At a basal level it’s funny to consider that a large fraction of the orthorexic noosphere is taking heaps of cheese run-off as a primary protein source. Beyond being evolutionarily inconsistent (cheese manufacture involves the introduction of rennet, a group of enzymes mostly found in ruminant animal stomachs, to coagulate/curdle milk proteins), the amino acid profile of whey proteins tends to not really approximate the AA profile from direct animal sources (both in muscle tissue and viscera): see below for a comparison to beef protein isolate and collagen as an imperfect proxy. And yes dear reader, I am making an appeal to nature in this line of reasoning, a fallacy that I don’t view as much of a fallacy at all when it comes to dietary intervention.
While AA profiles can only evince so much on a perfunctory pass, but there are notable deltas that should raise an eyebrow (see glycine for example). A more detailed look would suggest that there are other important differences, namely that the % free AA in whey protein concentrates/isolates are alarmingly high. Naturally occurring proteins will largely occur in polypeptide chains that are cleaved by proteases in the normal digestion of protein. In whey, a substantial fraction of AA’s like glutamate (AA primarily acting on umami taste receptors) and histamine/histidine are freely occurring as epiphenomena of cheese curdling in a low pH environment as lactic acid is produced from lactose by rennet and other digestive enzymes. As a result, a large bolus of unbound neurotransmitter precursor AA’s are dumped in circulation with whey consumption — this may be inconsequential for the goal of muscle protein synthesis but rather consequential neurologically.
Unbound glutamate is decidedly problematic; it’s the primary excitatory neurotransmitter in the CNS and can induce excitotoxicity when present in sufficiently high concentrations in the brain. Whether or not substantial amounts of unbound glutamate can cross the blood-brain barrier when occurring in serum is hotly debated, though many people people swear to have the putatively illusory MSG sensitivity (mono-sodium glutamate is a synthetic salt made by adding a sodium molecule to glutamic acid) that induces headache and OCD-like tendencies. And further there are some mechanistic reasons why some glutamate/glutamic acid may bypass regulatory controls at the BBB.
Anecdotally, I’ve seen a raft of reports that whey derivatives induce headache and other undesirable side effects when surfeited. So while AA profiles may be somewhat similar between meat and whey-derived protein, the nature of these profiles is substantially different enough to warrant circumspection.
Good point, but for the smol-brained reader, what protein supplement should I be using?