Whey Protein Supplements--Buyer's Guide
What is whey protein?
Whey is made from cow's milk and is the liquid portion left over from cheese/yogurt making. This whey is a combination of milk carbohydrates (lactose), milk protein, and milk fats (whey retains about 50% of the nutrients of the original milk [source]). Whey protein, which is processed from whey, is considered a complete protein source as it contains all 9 essential amino acids and is readily digested with high bio-availability making it one of the best sources of nutritional protein [source] we know:
Why would you supplement with whey protein?
What is the difference between whey protein "isolate", "concentrate", and "blend"?
- ISOLATE - to be called an ISOLATE the whey protein MUST contain 90%+ protein (typically 92% [refer to table below])
- CONCENTRATE - ANY whey protein that contains less than 90% protein (i.e. not an ISOLATE) is a CONCENTRATE. Whey protein CONCENTRATES typically contain 34-80% protein [refer to table below].
- BLEND - is a mixture of whey protein ISOLATE and whey protein CONCENTRATE
The reason that people prefer ISOLATE over CONCENTRATE/BLEND is that the ISOLATE is relatively free of both fats and lactose, significantly reducing indigestion/gas (particularly for the lactose intolerant) and providing cleaner macros. An important added benefit to ISOLATE is that, because it is relatively free of milk fat, it is relatively free of fat-soluble hormones (like estrogen) that are pumped into cows to keep them producing milk. The only major downside to ISOLATE is that it is more expensive than CONCENTRATE or BLEND.
It's important to realize that whey is a globally traded commodity. That means that it's strictly regulated, so that it's fungible (doesn't matter the producer, regulations ensure it's all the same--like a barrel of crude oil), and it's price is basically the same for everyone (again like a barrel of crude oil).
Why does the protein "isolate" I purchase have less than 90% protein per scoop?
The whey protein supplements we purchase are a mixture of the whey protein isolate and a bunch of other stuff that the supplement manufacturer adds to it (flavouring/colouring/emulsifiers/stabilizers). These additional ingredients slightly decrease the relative amount of protein. Another issue is the fact that Canadian nutritional guidelines require that all protein above 0.5g must be rounded to the nearest gram on nutritional labeling [Source]. This can introduce a very significant error based on rounding, particularly at smaller scoop sizes. For example, take a look at the Kaizen label below:
Going off the nutritional labeling we would calculate the % protein to be 83%. But if scoop size were 15g, the same nutritional label would give 87% protein because of rounding errors. However, because Kaizen tells you exactly how much WPI is in each scoop, we can calculate the actual protein percentage as 86% (based on the typical 92% whey protein content of isolate).
What does "grass-fed"/"hormone-free" mean? Why is it so expensive and is it worth the premium?
The typical dairy cow is fed a commercial meal product which are full of hormones (like estrogen) to promote milk production [source]. Unfortunately, these hormones are present in milk and despite being of bovine origin do stimulate responses in human tissue [source]. Whey protein derived from "grass-fed"/"hormone-free" cows means the cows were exclusively fed on grass pasture without artificial hormones. These cows naturally produce less milk, which makes this protein significantly more expensive.
BUT, steroid hormones like estrogen are lipid soluble and so fractionate with the milk fat. Because whey protein isolates (in particular) are virtually free of fat, they are relatively free of steroid hormones. Meaning you're probably getting way more steroid hormones from eating cheese, butter, yogurt, and milk than you'll get from whey protein. Non-steroid hormones which do fractionate with the whey protein are generally denatured by the pasteurization process and chopped up by proteases added to the whey protein--meaning they won't be biologically active when you ingest them.
So, imo, there is no compelling reason to pay the steep premium for "grass-fed"/"hormone-free" whey protein, especially if you already eat other dairy products.
What does "GMO-free" mean? Should I care about soy/sunflower lecithin?
A lot of protein powders we buy contain lecithin as an emulsifier. An emulsifier is an agent that helps the protein mix in water quickly (so its inclusion is a good thing!). Lecithin is an oil extracted from a variety of plants including soy and sunflower. A label indicating "non-GMO" is referring exclusively to the source of this lecithin--i.e. is it from a genetically modified soy crop (there are NO genetically modified sunflower crops that I know of, and we aren't at the stage of commercially available genetically modified cows yet). If you care about GMOs then you could try to avoid whey protein that has soy lecithin--MyProtein for example is switching exclusively to sunflower lecithin. I personally (as a biochemist) couldn't care less about eating GMOs (though ecological impacts and business practices are another issue).
The other issue raised about soy lecithin is that it contains phytoestrogens that, like bovine estrogens, have been shown to elicit responses in human tissues [source]. Again, this is something I don't worry too much about. Soy lecithin is one of the most ubiquitous food additives, it's in almost any processed food that involves an emulsion, dough, frying, syrup, chocolate, sticky ingredients, etc., etc.. The tiny amount you're getting in your whey isn't a drop compared how much you're getting from everything else. Besides, Asian diets, like the Japaneses diet, which consume on the order of 10x more soy than we do [source], have better health outcomes than we do. Consistent with this, no large study has found any conclusive evidence of adverse affects from phytoestrogens on human populations (men, women or children [source]).
If you are worried about soy phytoestorgens, get a protein that uses sunflower lecithin (e.g. from MyProtein), or better yet, a protein that doesn't use lecithin at all (Revolution-Nutrition Bulk Whey Isolate--but this will be harder to mix).
What is protein spiking?
The easiest way to measure the protein concentration of a powder like this is to measure the nitrogen concentration and extrapolate the protein content from that (because you know how many nitrogen atoms an average distribution of amino acids contains). Shady supplement companies can cheat this type of test by spiking their protein with amino acids that have a lot of nitrogen like arginine or other cheap nitrogen-rich compounds like creatine, leading to a substantial over-estimation of total protein content.
Alternatively, some companies spike by just adding cheap "filler" amino acids like glycine or taurine which are much cheaper than whey. There are a large number of companies that are currently involved in class-action lawsuits because of alleged protein spiking. This list of alleged protein spiking companies was generated from just the first few google hits:
How can you tell if your protein is spiked?
One quick test you can do is to look at the amino acid breakdown of the whey powder you're buying (if the manufacturer provides this information), and confirm that the Leucine makes up 10-11% of the total protein content (by mass). For example, I've shown how you can do this using the amino acid breakdown for Revolution-Nutrition's Pure Isolate below [source for amino acid table of whey isolate].
Ultimately, though, you're going to end up relying on information provided by the manufacturer which might not be accurate. So, with so many shady players in the supplement game, it's probably best to stick with well established brands of protein (like MyProtein) or brands that have been sold in stores like Costco that have a very strict vetting process (like Kaizen or Revolution-Nutrition).
How do I make sense of whey protein ingredients?
Protein powder is pretty simple, it has the same basic ingredients: protein source, flavouring/colouring, emulsifiers/stabilizers, digestive enzymes (proteases, lactase), and sweetener. Lets go through these one by one and point out what to look for and what to look out for.
- Protein Source: As mentioned above, most people will prefer whey isolate as the only protein source. This will be listed as "Whey Protein Isolate" (or sometimes "WPI", "WPI-90"). Beware of products listing a combination of "Whey Protein Isolate" and "Whey Protein Concentrate". This is a whey protein "blend", because the pure isolate has been mixed with concentrate of lesser purity--nevertheless some unscrupulous sellers will plaster the word "Isolate" all over their packaging (because it technically contains some isolate), despite the fact that it is in fact a blend.
- Flavouring/Colouring: This category is self explanatory. Pay attention to whether the product uses "artificial" or "natural" flavouring (most of us would probably prefer natural). Beware of products that go overboard with their flavours, for example including real cookies in their "cookies and cream". This will throw the nutrition off and you're probably buying protein powder for its clean nutrition and not its flavour.
- Emulsifiers: Emulsifiers, as discussed above, are agents that help solubilize the protein. Typical emulsifiers include soy lecithin and sunflower lecithin. Most would probably prefer sunflower lecithin because it has lower amounts of phytoestrogens, though the science does not indicate phytoestrogens are actually harmful and the ubiquity of soy lecithin in almost all processed foods makes avoiding it impossible. Beware products that don't contain any emulsifier as they will likely be much harder to mix. However if you have a proper shaking bottle with a shaker ball (highly recommended!), you might prefer emulsifier-free protein products (like Revolution-Nutrition bulk whey), which get you away from any phytoestorgen concerns.
- Stabilizers: Stabilizers are agents that help keep the protein in solution once it's solubilized, usually by thickening the solution which also improves taste because the protein is fuller bodied and stays on the tongue longer. Typically these agents are gums like Xanthan gum or Gaur gum. These are naturally derived agents (the Xanthan gum comes from the bacteria that causes black spots in plant leaves). I won't get into the geeky details of how these compounds work--although it's fascinating and the reason that your ketchup obeys non-Newtonian fluid properties which make it hard to get out of a bottle. Considering how ubiquitous Xanthan/Gaur gums are, and the tiny amounts involved there really is no need to be concerned about these.
- Digestive Enzymes: Frequently you'll find protein powders include digestive enzymes to break down proteins into smaller bits for faster digestion and sometimes lactase to break down any trace lactose. It's a plus if the product includes these, but it's not necessary. Remember, what makes whey protein one of the best sources of nutritional protein is that it scores so highly on measures of Protein Efficiency (i.e. animal growth per g protein ingested), Biological Value (efficiency of uptake of protein from blood), Net Protein Utilization (total efficiency of uptake of protein from gut to cells), and Protein Digestibility [source]. Also, isolate should be pure enough of lactose that lactase isn't necessary.
- Sweeteners: Protein powder can use either sugar, natural sweeteners (stevia), artificial sweeteners (sucralose, saccharin, acesulfame) or some combination thereof. Most people will probably prefer natural sweeteners, but taste is subjective and at least in my opinion the best tasting protein powder products usually use artificial sweetener. Pay attention to products using actual caloric sweeteners sugar/honey/fructose/etc., and make sure that the added carbs aren't throwing the nutrition off too much and understand that they might spike insulin (for example, if on restrictive diets like strict keto).
Beware of protein powders that contain stuff beyond these ingredients, particularly ones that add individual amino acids like glycine, taurine, arginine or derivatives of creatine--that's a pretty good indication that they're spiking.
[more to come]