Whey protein is the highest quality protein known to man. It has the highest amounts of Branched Chain Amino Acids (BCAAs) and Essential Amino Acids (EAAs), plus more leucine than anything else on the market. So why can’t you just drink some amino acids and get the same results?
It sounds reasonable at first, right? If whey is made up of BCAAs, EAAs and other amino acids, then it seems like you could just consume those amino acids on their own and get the same results. Or you could just dispense with them entirely and get everything you need from whey protein. But that’s not what happens. You actually get different results depending on whether you consume whole protein as opposed to amino acids or a meal that contains those exact same amino acids.
Firstly, let’s talk a little philosophy, specifically logic and the fallacies of composition and division (two separate mistakes).
The fallacy of composition is when we assume that the whole thing (whey protein in this case) is composed of the traits of each individual constituent (amino acids). This is like saying your car has a grey engine and a grey tailpipe, therefore your car is grey.
The fallacy of division is the opposite. Where we say something that is true of a particular thing is also true of each component part. A battleship will float but each individual part is not going to float on its own, like the guns for example.
Not every case involving these two fallacies will be automatically untrue – we can imagine a car made entirely of grey parts that would itself also be a grey car. But to use these forms of arguments is fallacious because they’re not always true (a valid argument is defined as being an argument from where the truth of the premise insures the truth of the conclusion). When we have a valid argument and the premises are true, it’s called a sound argument.
Ok, so we’re all on the same page now. Let’s look then at some less-theoretical examples and see how this kind of thing plays out in the real world when we compare a thing (whey protein) to its individual parts (amino acids).
A 2006 study on the elderly (which is admittedly imperfect for our purposes of extrapolating this to athletes) examined the anabolic effect of a 15g feeding of either EAAs or whey protein (the whey had less total EAA, obviously). While both the EAA and whey protein elevated the rate of muscle protein synthesis (as measured by fractional synthetic rate), the EAAs actually did so to a greater extent than the whey protein. The EAAs were more anabolic, or muscle-building, in other words. So we’d be committing the fallacy of composition if we were to think that the whey protein provided exactly the same benefits of its parts (in this case EAAs). In this context the EAAs represented a more efficient method of administration.
However, another study, again in the elderly (with the same authors), was performed where fifteen elderly people were randomly assigned to ingest a bolus of either 15g of whey protein, 6.72g of EAAs, or 7.57g of nonessential amino acids (NEAA). In this case it was found that the anabolic effects of whey were greater (as measured by phenylalanine balance). The researchers concluded that whey protein improves skeletal muscle protein accrual through mechanisms that are beyond those attributed to its EAA content.
Unfortunately, both of these studies used different measures of protein synthesis. While you can (sort of) compare studies that examine one marker or another, you can’t compare studies that rely on different ones, because the differing methodology can give disparate results.
However, in a third experiment, the same researchers compared healthy young males consuming a drink containing 30g of carbohydrate and 15g of EAA versus a liquid mixed meal (850 calories, but with the same EAA content of 15g), or both (the drink and the liquid meal). The group that received both the meal and the drink had the best anabolic environment (measured by FSR and phenylalanine). However, the real gem to be dug out of this study is that the drink (30g of protein + 15g of EAA) produced better results than the big liquid meal. This means when we compare 180 calories of carbs and EAAs to 850 calories containing the same EAAs, the much smaller caloric intake actually performed better.
This is interesting because carbohydrates are able to positively affect whole body nitrogen retention. More accurately, ingesting carbohydrates will decrease the rate of protein lost through metabolism – they improve your net protein balance. However, this doesn’t mean that they’re going to improve actual muscle protein synthesis as they aren’t going to contribute protein to your muscles on their own. They’re just going to delay the rate at which your body goes through it.
Ingesting carbohydrates will decrease the rate of protein lost through metabolism – they improve your net protein balance.
Of the twenty-odd amino acids, it’s important to remember that only three are oxidised for energy during exercise – the BCAAs. And although they’re not oxidised at the same rate as carbs during anaerobic training, or even fats during aerobic raining, they’re still oxidised (which is a shame for recovery purposes because they’re highly anabolic). They’re also able to stimulate muscle protein synthesis as effectively as the nine essential amino acids (so, in this case, three amino acids are just as good as nine).
Besides the incredibly high BCAA and EAA content of whey protein, it’s thought that the amino acid leucine (in particular) may be largely responsible for whey’s anabolic effect.
Out of the three BCAAs only leucine was able to independently stimulate muscle growth. So you’d think that we can add leucine to whey protein and come up with some kind of super-shake, right?
Remember the fallacy of composition from earlier in this article? Unfortunately, adding leucine to a whey protein drink doesn’t stimulate any additional muscle protein synthesis. According to one of the leading researchers on whey, “Our results indicate that the whey protein plus leucine in healthy young volunteers results in an anabolic response in muscle that is not greater than the previously reported response to whey protein alone.”
Still, there’s some nutritional slight of hand that we can pull with regard to leucine – if you’re not already consuming an optimal dose of whey; a six(ish) gram shake of whey protein supplemented with either leucine or a mixture of EAAs without leucine was shown to stimulate muscle protein synthesis on the level of 25g of whey protein under resting conditions. But when we’re talking about post-exercise conditions, the 25g of whey is superior. So once again the whole appears to be different than the parts, at least situationally.
And while EAA plus carbs are best taken pre-workout, a whey protein shake can be taken either before or after with similar results. This leaves little doubt that in the case of whey protein, the sum is different than the parts that make it up. But not always.
In the case of whey’s insulinogenic (insulin generating) effects in vitro, they are thought to be a direct result of certain amino acids found in whey (i.e. leucine, isoleucine, valine, lysine, threonine). But what this means is that we are not always assured that the parts of a whole will do the same thing as the individual parts, even though they sometimes do.
Generally, because whey protein is so incredibly high in EAA, BCAA and leucine we can expect to get some (though not all) of the effects generally found with each of its constituents, and some effects that are not generally found with them. As for the other NEAAs, it would appear that the composition of this protein has very little to do with the anabolic response. As such we can safely say that these amino acids in particular are no doubt huge contributors to the anabolic effects of whey.
However, whey contains various bioactive peptides that act to enhance recovery and can potentially positively affect the adaptive process to exercise in other ways. These bioactive peptides are not found in EAAs, BCAAs or leucine, and appear to be a unique quality to dairy proteins. So what we can’t say is that these amino acids are the deciding factor in whey’s effects… or that we can use one in place of the other (interchangeably) in all cases.