Whey Protein has been somewhat completed, with some minor edits to come in the next few days (sprucing up reportedly weak areas) and perhaps an overhaul within the next two months.
Whey was interesting to research since it was very hard to delineate what was the benefit of 'Whey' from what is an inherent benefit of 'Protein'. Science on both topics has been included on the Whey Protein page.
The following bullets are either highly notable points found, or benefits of whey specifically. Keep in mind that most benefits of whey protein specifically get 'washed out' when you merely over-consume protein:
L-Cysteine, the amino acid, can pretty much be a vitamin and has a subclinical deficiency state related to its underconsumption; either through glutathione (antioxidant enzyme) or hydrogen sulfide (nitric oxide 2.0 apparently). Whey is the most cost-effective and efficient way to replenish cysteine stores, but this can also be done with just more protein in general or N-AcetylCysteine (NAC) supplementation. I would recommend against reduced glutathione supplementation, because aside from low bioavailability issues it cannot convert to H2S
If you are borderline on protein intake (0.8-1.2g/kg bodyweight, assuming not overweight or obese) then whey protein is a better option than other proteins for inducing protein synthesis and aiding in fat loss. This is due to whey being efficient, and this apparent benefit is lost when protein intake is increased (1.6g/kg appears to be cited in one study, I could not find the exact 'roof' where whey loses its benefits)
We have a nutrient timing section! Apparently the 1 hour window exists for fasted training with no amino acid preload, but having amino acids in your body may render timing useless; 24 hour AUC for protein is still more important than 1 hour AUC though Whey, due to its Glutamine content, is quite gut healthy and has reduced intestinal permeability (good thing) in humans with Crohn's disease before. However, due to the glutamine content this may also apply to casein and Milk Protein in general (casein is higher in glutamine). Milk would have lactose though, which is not too friendly to an ill intestinal wall
Apparently whey is healthy, reducing post-prandial triglycerides and, over time, reducing total cholesterol and increasing HDL more than Casein Protein. Benefits are more apparent in type II diabetics, where the reduction of triglycerides are highly associated with greater insulin sensitivity after meals
Also has anti-cancer properties, although of unknown potency; preliminary stuff, but some of the quaternary proteins such as lactoferrin and alpha-lactalbumin may be anti-cancer; the latter even more-so when formed into HAMLET/BAMLET, but that has not been demonstrated in vivo yet
In the end, Whey Protein appears to be about efficiency. It is a great thing to note, but efficiency is at many times washed out with excess.
Whey Protein seems to be a good idea to people who currently underconsume protein or would find that whey is cheaper than alternatives when staying near a moderate to low protein intake (0.8-1.2g/kg)
Whey protein can potentially benefit older individuals (60+?) much more than youth, the mechanisms have not been added to Examine yet; not sure if they are known right now.