SCIENCE Whey is one of two protein naturally occurring proteins found in milk with the other being casein. There are three different types of whey proteins you can find on the market: Whey Protein Concentrate (WPC), Whey Protein Isolate (WPI), and Whey Protein Hydrolysate (WPH). Whey Protein Concentrate - Containing 80% protein content per gram, WPC is a traditional source of protein as it contains high levels of growth factors including IGF-1, TGF-1 and TGF-2. Containing a rich amino acid profile and a high bioavailability, WPC also contains beneficial components including natural lipids including conjugated linoleic acid (CLA) and high levels of naturally occurring immunoglobulins and lactoferrin that can contribute to immune system health and metabolism. One issue that some may have with WPC is that is naturally will have a higher lactose content compared to that of a WPI or WPH protein, making it not an ideal choice for some. Whey Protein Isolate - Often regarded as one of the purest forms of whey protein, WPI contains an average of 90% of its weight coming from protein with minimal lactose and fat, which is great news for those sensitive to lactose and looking to keep their calories in check. It is fast digesting, contains high levels of the anabolic amino acid leucine and has minimal fats or lactose. Whey Protein Hydrolysates (WPH) - Taking whey protein isolate a step further, WPH is whey protein that has been broken down or “pre-digested” into shorter chains called peptides. This makes this type of whey protein more easily absorbed by the body. Hydrolyzed whey protein is often used in infant formulas and sports and medical nutrition products. Hydrolyzed Whey Protein Effect on Absorption and Muscle Protein Synthesis Research suggests that Hydrolysis results in greeter delivery of amino acids from your stomach to muscles, and it may also enhance the speed of delivery when compared to an intact protein. This process results in the cleaving of intact whey proteins into shorter (i.e., di-, tri-, and oligo-) peptides which speeds intestinal absorption and thereby augments the rate of amino acid availability following ingestion. As a result, there's less time needed initiate protein synthesis. It has also been shown that naturally occurring leucine content in whey protein hydrolysate (14.2%) is also higher compared to whey isolate (12.2%). In a study comparing the effects of whey protein hydrolysate to casein hydrolysate (a fast-absorbed form of casein), whey protein resulted in greater muscle protein synthesis over 8 hours after 20g at rest. Furthermore, it has been observed that Whey hydrolysate increased protein synthesis by 15%, while casein hydrolysate (10%) and regular casein (8%) had lower effects. One study found that when amino acids or whey protein hydrolysates were administered after exercise, whey protein hydrolysates was superior to amino acids for stimulating muscle protein synthesis and initiating translation. This study suggests that when identical amounts of amino acids are compared to whey protein hydrolysates, there is something additional in whey protein hydrolysates that stimulates greater muscle protein synthesis. Another study found that whey protein hydrolysates was superior to amino acids for stimulating muscle protein synthesis and stimulating anabolic pathways. Whey Protein Hydrolysates Effect on Muscle Recuperation The faster you can recuperate from exercise, the quicker you can get back in the gym and train. Whey protein hydrolysate induces a substantially greater insulin response compared to intact proteins (isolate or concentrate), which may facilitate superior glycogen replenishment and a greater anabolic response when consumed post-workout. Another study found that subjects consuming whey hydrolysate post-workout experienced better recovery and performance shortly after a muscle-damaging bout of exercise than those consuming whey isolate. In this study, researchers had 28 subjects complete 100 eccentric-focused repetitions on the leg extension. Eccentric muscle contractions are extremely damaging to muscle and result in intense muscle soreness several days after. Immediately following exercise, subjects consumed either 25 grams of whey hydrolysate, 25 grams of whey isolate, or a protein-free placebo. The whey hydrolysate group was able to recover faster (~6 hours later), whereas the placebo and whey isolate group took longer (~24 hours later). Another study focused on the consumption of whey protein hydrolysates by women soccer players. The studies indicated that hydrolyzed whey protein resulted in significant decreases in the muscle damage indicators, creatine kinase (−42%) and lactate dehydrogenase (−30%), compared to increases in the carbohydrate group.Whey Protein Hydrolysates Effect on Fat Loss One of the other remarkable effects of whey protein hydrolysates have over other proteins is the ability to enhance fat loss. A 2018 study found that whey protein hydrolysates elicited a significant decrease in fat mass compared to the placebo condition, whereas whey protein concentrate did not. The researchers suggested that this may be due to increases in the fat burning hormone epinephrine. Another 2018 study found that military cadets taking whey protein hydrolysates twice per day had improved push-up performance and greater reductions in fat mass during training in comparison to carbohydrate supplementation. In a previous study, compared whey protein concentrates, whey protein hydrolysates elicited a robust increase in circulating epinephrine. In a study in resistance trained men, whey protein hydrolysates facilitated greater fat loss than whey protein concentrate. One study that compared the effects of whey protein concentrate to whey protein hydrolysates or a maltodextrin placebo on body composition, performance, and biochemical markers in elite Brazilian soccer players during 12 weeks of intense training. The whey protein hydrolysates group exhibited a significant decrease in biochemical markers associated with muscle damage and catabolism demonstrating unique anti-catabolic properties not present in whey protein concentrate. Lastly, a study reported that twice daily supplementation with 30 g of whey protein hydrolysates during 8 weeks of resistance training in college-aged males resulted in a 6% decrease in fat mass compared to an iso-caloric carbohydrate placebo, while a whey protein concentrates treatment group did not exhibit these same effects.
