By Maria Cohut

Fact checked by Paula Field

As more and more people are turning away from meat in favor of plant-based and meat replacement products, scientists are asking more questions about how protein sources differ from one another. New research looks at whether animal or fungus-derived protein is better for building muscle mass.

Traditionally, some people have considered that animal products are the best source of protein for health. Recently, however, various studies have questioned this point of view.

For instance, one 2017 study from the University of Exeter in the United Kingdom suggested that fungus-derived protein(mycoprotein) may be just as good for physical health as animal protein, such as milk protein.

Mycoprotein is a processed, nutrient-derived form of a strain of the microfungus Fusarium venenatum, which naturally contains a high amount of protein.

For that study, the research team — led by Benjamin Wall, Ph.D. — collaborated with and received funding from Quorn Foods, a company that produces plant-based meat replacement products, and which uses mycoprotein as the protein source in their foods.

Recently, continuing their collaboration with Quorn Foods — which distribute their product in some European countries, including the U.K., and in the United States — Wall and colleagues have gone on to find out exactly how mycoprotein compares to animal protein (specifically, milk protein) in terms of contributing to muscle mass growth.

The food company declared for Medical News Today that “Quorn Foods provide funding for Exeter University’s research into mycoprotein and support their commitment to publish the results regardless of the findings.”

The researchers have presented their latest findings at the European College of Sport Science’s 2019 Congress, which this year takes place in Prague, the Czech Republic, between 3–6 July.

Over 120% boost in muscle building rates

As part of the current research, the investigators assessed the digestion of protein in 20 young, healthy male participants. In protein digestion, amino acids — which make up proteins — pass into the bloodstream, thus becoming available for the building of muscle mass.

The researchers evaluated muscle building rate while the volunteers were at rest after having participated in a session of strenuous resistance exercise, and after having consumed either milk protein or mycoprotein.

Wall and team found that the participants who had received milk protein were able to boost their muscle building rates by up to 60%. However, those who consumed mycoprotein instead increased their muscle building rates by over 120%.

The investigators note that their findings bode well for non-meat eaters, as they show that fungus-derived protein could effectively replace animal protein for muscle building or maintenance.

“These results are very encouraging when we consider the desire of some individuals to choose non-animal derived sources of protein to support muscle mass maintenance or adaptations with training,” says Wall, who is associate professor of Nutritional Physiology at Exeter.

“Our data show that mycoprotein can stimulate muscles to grow faster in the hours following exercise compared with a typical animal comparator protein (milk protein) — we look forward to seeing whether these mechanistic findings translate to longer-term training studies in various populations.”

Benjamin Wall, Ph.D.

Other studies conducted by members of Wall’s team have hailed mycoprotein as “a healthy new protein with a low environmental impact,” yet some researchers have questioned its safety, pointing to reports of allergic reactions to mycoprotein-containing foods.