NEVERSECOND: What is the Best Protein?

Introduction

Protein plays a major role in the repair process after exercise. The process that repairs damaged muscle proteins, muscle protein synthesis, is key to get the exercise-specific adaptations that we want to get with our training. The result for the athlete? Better adaptation and performance gains, all of which can be affected by the type of protein consumed.

What makes a protein effective?

There are three critical factors that dictate the effectiveness of a protein:

1. digestibility
2. essential amino acid profile, and
3. the amount of protein provided

Digestibility is important because the protein contained in food needs to be absorbed into the bloodstream in order to be used by muscles. Protein composition is also extremely important: of the 20 amino acids needed to build muscle, only 11 can be made in the human body, while the other 9 must be ingested from food. Finally, the amount of protein consumed is also critical as it provides the optimal environment to repair and build new muscle proteins.

Of the 20 amino acids needed to build muscle, only 11 can be made in the human body, while the other 9 must be ingested from food.

So, what about leucine?

Leucine is an especially important amino acid and muscle cells can sense its presence. When leucine concentrations rise above a certain level, it communicates to the muscle to start creating new proteins. Some proteins like whey protein have a relatively high concentration of leucine so it is easier to achieve the amount of 3 grams of leucine per meal which is thought to “trigger” protein synthesis.

Is animal or plant protein better for athletes?

Plant protein has been getting a great deal of attention lately as consumers pursue plant-based diets in greater numbers. But how does plant protein stack up when compared to animal (whey) protein?

• Digestibility: Many studies show that plant-based proteins have a lower digestibility (45-80%) when compared with animal-based proteins (around 90%). The infographic below summarizes different food sources and their digestibility.
• Amino acid composition: Research also demonstrates that animal proteins have a higher essential amino acid content (45-50%) compared to plant-based sources (30-40%).
• Leucine content:Master regulator leucine is found in higher concentrations in animal sources (8-13%) when compared to plant sources (6-8%).

Recommendations

When considering digestibility, essential amino acid profile and leucine content, animal protein (specifically whey protein) is most effective. Athletes consuming mixed diets should prioritize lean animal-based proteins, but also include plant-based protein sources as they contain other compounds such as antioxidants that may benefit recovery and overall health.

Vegetarian and vegan athletes should use a grain-legume combination diet as they complement each other’s essential amino acid inadequacies. Foods such as grains, legumes, nuts, seeds and beans should be regularly consumed to provide the full spectrum of amino acids. Vegetarians could perhaps consider supplementing with a whey protein powder to ensure you are optimizing your protein intake. Vegans could use mixes of various plant-based protein sources such as wheat, rice and pea protein.

References

• Gorissen, SHM, Crombag, JJR, Senden, JMG., Waterval, WAH, Bierau, J, Verdijk, LB, & van Loon, LJC. Protein content and amino acid composition of commercially available plant-based protein isolates. Amino Acids, 50(12), 1685–1695, 2018.
• Gorissen, SHM, & Witard, OC. Characterising the muscle anabolic potential of dairy, meat and plant-based protein sources in older adults. Proceedings of the Nutrition Society, 77(1), 20–31, 2018.
• Joy JM, Lowery RP, Wilson JM, Purpura M, De Souza EO, Wilson SM, Kalman DS, Dudeck JE, & Jäger R. The effects of 8 weeks of whey or rice protein supplementation on body composition and exercise performance. Nutrition Journal, 12(1), 86, 2013.
• Thomas, DT, Erdman, KA, & Burke, LM. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. Journal of the Academy of Nutrition and Dietetics, 116(3), 501–528, 2016.
• Van Vliet S, Burd NA, & Van Loon LJ. The Skeletal Muscle Anabolic Response to Plant- versus Animal-Based Protein Consumption. Journal of Nutrition, 145(9), 1981–1991, 2015.