Protein is so popular these days that it seems nobody can get enough of it. Not getting enough protein can literally be a struggle, however, partly because certain factors impede our ability to fully digest and use the protein we consume. That’s why ingredients that promise to “boost” protein’s power are attracting more and more attention these days. But what do we really know about how these ingredients unlock protein’s potential—and what evidence do we have that they actually do so?
One thing we do know is that as a trending nutrient, protein maintains its pull. Notes Shawn Baier, MS, MBA, chief operating officer, Metabolic Technologies Inc. (Ames, IA), “We’re most definitely still talking about protein. In sports nutrition, it’s front and center as a key product feature.”
To wit: Fully 90% of the 7+% CAGR that Technavio predicts for the U.S. sports-nutrition market by 2019 will likely come from sales of protein products, says Mallory Junggren, marketing director, Nutrition 21 (Purchase, NY). “This proves that protein products remain the bedrock of the sports-nutrition industry,” she declares.
But protein’s popularity extends beyond sports enthusiasts. Recent years have seen the macronutrient colonize mainstream meal replacement and healthy snack formulations, says David Keller, vice president of scientific operations, Ganeden (Cleveland). A 2017 Ganeden-sponsored Survey Sampling International (SSI) look at the buying habits of health-conscious consumers found nearly half of all respondents select protein products as “typically purchased items,” Keller notes, “showing that there’s still a large amount of interest in the category.”
What Doesn’t Kill You Makes You Stronger
But for athletes and active types, protein serves a very particular purpose. As Jim Komorowski, chief science officer at Nutrition 21, explains, “During exercise, or just periods of heightened physical activity, muscle fibers are damaged, making them more susceptible to fatigue or injury.” Counterintuitively, it’s this fatigue that signals the body to begin a process called muscle protein synthesis (MPS), “which works to repair and replace damaged muscle fibers through fusing them together into new, strong muscle-protein strands,” Komorowski continues. “As these strands increase in number and thickness, they create muscle growth.”
To feed that growth, the body needs muscle tissue’s basic building blocks: amino acids. And “for those athletes pushing their bodies in training and performance,” says Baier, “dietary protein provides a source of these necessary building blocks to build new and repair existing muscle.” When dietary protein is insufficient, “the body turns to its own muscle tissue to meet the requirement for amino acids,” he says—which kind of defeats the purpose of muscle-building exercise in the first place.
On the Level
Just how much protein athletes and active people need is a moving target, as no two bodies—and no two bodybuilding regimens—are alike. But this we can conclude: “Compared to the RDA, athletes and active people need more protein to ensure they’re meeting the elevated demand for muscle repair and recovery,” Baier says.
A “common approach” he’s observed among athletes is to consume 1 gram of protein per kilogram of body weight “at a minimum,” Baier says, though he’s also seen recommendations for as much as 2 grams per kilogram for some athletes.
Indeed, Ralf Jäger, FISSN, CISSN, MBA, managing member, Increnovo LLC (Milwaukee), notes that intakes of up to 2.3 to 3.1 grams protein per kilogram of body weight per day “may be needed to maximize the retention of lean body weight in resistance-trained subjects during hypocaloric periods.” While emphasizing that optimal intakes for maximizing MPS will vary, he says that 0.25 gram1 of high-quality protein—that is, protein rich in essential amino acids and especially the branched-chain amino acid (BCAA) leucine—per kilogram of body weight, or an absolute dose of 20 to 40 grams, makes for a wise general recommendation. “These protein doses should ideally be evenly distributed every three to four hours across the day,” Jäger adds.
Barriers to Entry
So, are gym rats and weekend warriors getting their fill? Given the surfeit of protein-packed products in workout bags, it would be puzzling if they weren’t. But either way, as important to athletes as the amount of protein they take in may be what their bodies do with that protein once it’s in there.
As John Deaton, vice president of science and technology, Deerland Enzymes & Probiotics (Kennesaw, GA), says, “Many athletes and active individuals are consuming more protein in one sitting than their bodies can effectively digest and use.” Whey protein, for instance—the gold standard for MPS thanks to its full complement of essential amino acids and the BCAAs leucine, isoleucine, and valine—requires hydrolysis to smaller particles within 90 minutes of consumption to be effective. Yet “it takes approximately 90 minutes for whey to pass from the stomach through the small intestine for digestion, absorption, and assemblage into a bio-usable form for muscle synthesis,” he explains. Undigested portions go right through the body, “rendering them useless to active individuals hoping to improve muscle recovery.”
What’s more, the body’s failure to hydrolyze whey protein into smaller bits leaves larger peptides in the digestive tract, where they produce the bloating, nausea, and cramping that plague many who consume a large amount. “Some may chalk up these discomforts to lactose intolerance, since whey is a dairy protein,” Deaton notes. “However, lactose isn’t present in whey isolates.” The culprit, rather, is the whey itself.
And even if smooth digestion and thorough hydrolysis were a given, there’s another potential barrier to athletes’ ability to pack in enough protein: “Consumers may just get tired of taking their regular high-protein products because they don’t like the flavor,” Baier notes.
No wonder “simply throwing large amounts of protein into the diet doesn’t necessarily accomplish the goals of optimizing recovery or muscle health,” he concludes. The key lies in shifting protein metabolism “in the right direction”—increasing protein synthesis while reducing protein degradation—“resulting in a net increase in protein for muscle growth and repair,” he says.
Protein marketers and sports-nutrition formulators have been looking for ingredients that give protein metabolism just that kind of nudge, as such ingredients promise not only to improve the efficacy of protein products, but to open a new arena of development for sports nutrition and protein products overall.
One such ingredient is ß-hydroxy-ß-methylbutyrate (HMB). Produced in the body during the metabolism of leucine, it’s “one of the most researched sports-nutrition ingredients,” Baier says, “and has mechanism-of-action data to support its benefit on protein synthesis as well as its minimizing effect on protein breakdown.”
How? It follows a “unique mechanism of action,” says Jäger, “having been shown to increase muscle protein synthesis via the mTOR pathway”—a signaling sequence that lets cells regulate their lifecycles—“while simultaneously inhibiting muscle protein breakdown via the proteasome pathway.”
By “shifting protein metabolism in a positive direction this way,” Baier says, HMB lets the body better use protein’s amino acids for muscle growth and repair. What’s more, it may help us better use plant proteins, which have an amino-acid profile and leucine content “considered less optimal for athletes and active persons,” Baier notes. “When HMB was combined with a plant-based protein in a recent study,” he says, “the plant-based protein performed more like the whey counterpart.”2
- Jäger R et al., “International Society of Sports Nutrition Position Stand: Protein and Exercise,” Journal of the International Society of Sports Nutrition. Published online June 20, 2017.
- Rittig N et al., “Anabolic effects of leucine-rich whey protein, carbohydrate, and soy protein with and without ß-hydroxy-ß-methylbutyrate (HMB) during fasting-induced catabolism: A human randomized crossover trial,” Clinical Nutrition, vol. 36, no. 3 (2017): 697-705
- Minevich J et al., “Digestive enzymes reduce quality differences between plant and animal proteins: a double-blind crossover study,” Journal of the International Society of Sports Nutrition. Published online September 21, 2015.
- Gepner T et al., “The combined effects of Bacillus coagulans GBO-30, 6068 and HMB supplementation on muscle integrity and cytokine response during intense military training,” Journal of Applied Physiology. Published online April 13, 2017.
- Keller D et al., “Bacillus coagulans GBI-30, 6086 increases plant protein digestions in a dynamic, computer-controlled in vitro model of the small intestine (TIM-1),” Beneficial Microbes, vol. 3, no. 3 (2017): 491-496
- Jäger R et al., “Probiotic Bacillus coagulans GBI-30, 6086 reduces exercise-induced muscle damage and increases recovery,” PeerJ. Published online July 21, 2016.
- Wolfe RR., “Effects of insulin on muscle tissue,” Current Opinion in Clinical Nutrition and Metabolic Care, vol. 3, no. 1 (January 2000): 67–71
- Evans GW, “The effect of chromium picolinate on insulin controlled parameters in humans,” The International Journal for Biosocial Research, vol. 11 (1989): 163–80
- Siegenfuss TN et al., “Effects of an amylopectin and chromium complex on the anabolic response to a suboptimal dose of whey protein,” Journal of the International Society of Sports Nutrition. Published online February 8, 2017.