Insects have arisen as the latest novel protein source. In addition, more and more insects have been approved over the recent years by the EU as food sources. Although insects have been consumed as part of a habitual diet in some parts the world, insects are not a common food source in the western diet. Moreover, little is known about the effect of insect protein on our metabolism. Wesley Hermans from Maastricht University will discuss the results of his recent study about the anabolic properties of insects in this blog.
Why consume insects as a protein source
It has been well-established that protein ingestion stimulates muscle growth at rest and even more after exercise (1, 2). We have covered this topic in previous blogs (see an overview at the end of this article). However, most studies have investigated the muscle anabolic response following ingestion of animal-derived protein sources like eggs, beef and milk proteins (3, 4). With the growing interest in the environmental impact of our diet, there has been an increased search for alternative protein sources. Edible insects have been identified as a protein source that can be produced on a more sustainable commercial scale. Furthermore, various insect species have been identified to have similar amino acid compositions and protein content compared to commonly consumed animal proteins (5).
Can mealworm protein ingestion stimulate muscle growth?
Despite insect protein having a similar amino acid profile and protein content compared to animal-derived protein sources, it remained unclear whether insect protein ingestion can stimulate muscle growth to a similar extent. Therefore, we performed a study in which we measured the anabolic reponse following mealworm protein ingestion and compared this to milk protein ingestion (6). We recruited 24 healthy, recreationally active men who performed a single-legged resistance exercise session after which they ingested a shake containing either 30g of milk protein or 30g of mealworm protein. We then took blood samples and muscle biopsies over a 5-hour period. This allowed us to assess the blood amino acid availability as well as the acute muscle growth response at rest and after exercise. Because both the milk and mealworm contained labeled amino acids, we could additionally measure how much of the ingested protein was digested, absorbed into the circulation, and eventually incorporated into the muscle to contribute to the stimulation of muscle growth.
Insect protein study findings
We observed both mealworm and milk protein ingestion were properly digested and induced a similar increase in plasma amino acid concentrations. In addition, the muscle growth response (i.e. muscle protein synthesis rate) did not differ between both groups at rest and after the exercise. This shows that insect-derived proteins can be a good protein source to stimulate muscle growth. Another interesting aspect is the amino acids ingested via both protein sources (milk and insects) were already incorporated into the muscle tissue within 2 hours after the ingestion of the protein. This shows that you really are what you just ate; whether it is milk protein or insects.
Conclusion
In this study, we observed mealworm protein can be consumed to support muscle growth. Furthermore, the muscle growth response did not differ from milk protein. Therefore, if you are not afraid of eating insect proteins and/or want to avoid eating animal-based protein sources, you could consider putting insects on the menu!
References
Moore DR, Robinson MJ, Fry JL, Tang JE, Glover EI, Wilkinson SB, et al. Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men. Am J Clin Nutr. 2009;89(1):161-8.
Paddon-Jones D, Sheffield-Moore M, Katsanos CS, Zhang XJ, Wolfe RR. Differential stimulation of muscle protein synthesis in elderly humans following isocaloric ingestion of amino acids or whey protein. Exp Gerontol. 2006;41(2):215-9.
Burd NA, Gorissen SH, van Vliet S, Snijders T, van Loon LJ. Differences in postprandial protein handling after beef compared with milk ingestion during postexercise recovery: a randomized controlled trial. Am J Clin Nutr. 2015;102(4):828-36.
Van Vliet S, Shy EL, Abou Sawan S, Beals JW, West DW, Skinner SK, et al. Consumption of whole eggs promotes greater stimulation of postexercise muscle protein synthesis than consumption of isonitrogenous amounts of egg whites in young men. Am J Clin Nutr. 2017;106(6):1401-12.
Churchward-Venne TA, Pinckaers PJM, van Loon JJA, van Loon LJC. Consideration of insects as a source of dietary protein for human consumption. Nutr Rev. 2017;75(12):1035-45.
Hermans WJH, Senden JM, Churchward-Venne TA, Paulussen KJM, Fuchs CJ, Smeets JSJ, et al. Insects are a viable protein source for human consumption: from insect protein digestion to postprandial muscle protein synthesis in vivo in humans: a double-blind randomized trial. Am J Clin Nutr. 2021;114(3):934-44.
Related blogs and links
Dietary protein requirements for older athletes @LeighBreen