- Past searches reported that animal proteins may work better than plant-based alternatives when it comes to muscle protein synthesis.
- Studies have shown that potatoes can provide adequate amounts of all the essential amino acids humans need, but have failed to confirm their effects on muscle building.
- Researchers in the Netherlands have now found that a potato-derived protein concentrate powder can support muscle repair and growth, as well as animal milk protein in males.
A shift in favor of more plant-based foods is steadily gaining momentum around the world within the medical and athletic communities. However, some people continue to express concerns about the use of plants as a protein source in sports nutrition products.
Sports nutritionists have long believed that certain compounds in plants can reduce the bioavailability of proteins. Additionally, some research suggests that plants do not provide all of the essential amino acids available from meat sources.
A new study challenges these notions, suggesting that the humble potato may be as reliable a protein source as animal milk.
The research, which was partially funded by the Alliance for Potato Research & Education, appears in Medicine and science in sport and exercise.
Researchers from Maastricht University in the Netherlands conducted a study to evaluate how potato proteins promote anabolic reactions that increase muscle mass.
Dr. Luc JC van Loon, professor of exercise physiology and nutrition at Maastricht University Medical Center, was the principal investigator.
Talking with Medical news todayDr. van Loon shared:
“The [study’s] the main finding is that the ingestion of protein derived from potato can increase the rates of muscle protein synthesis at rest and during exercise and that this response does not differ from ingesting an equivalent amount of protein from the milk”.
“[P]Plant-derived proteins may be as effective as high-quality animal-derived proteins in stimulating rates of muscle protein synthesis in vivo in humans.
– Dr. Luc JC van Loon
Muscle protein synthesis (MPS) is the process by which amino acids become skeletal muscle proteins. Protein intake and exercise are vital for MPS to maintain and build skeletal muscle mass.
Protein consumed while recovering from exercise can increase MPS rates. These rates vary based on the protein source.
Potatoes, the third most consumed crop in the world, contain only 1.5% protein based on their fresh weight. However, a protein concentrate can be extracted from potato juice residue that is used for food or discarded.
Dr. van Loon and his co-authors found that the amino acid composition of potato proteins resembles that ofmilk proteins up close. They also stated that the tuber “provides sufficient amounts of all individual essential amino acids according to WHO / FAO / UNU amino acid requirements, with no apparent deficiencies.”
The team speculated that ingesting potato protein concentrate could increase MPS rates at rest and during recovery from exercise.
They also hypothesized that potato proteins may induce the same MPS response as milk proteins.
To test their ideas, Dr. van Loon and his team recruited 24 healthy, active males for a trial that took place between April 2018 and February 2020. Participants ranged in age from 18 to 35.
All subjects ate a standardized meal and fasted the night before the test days. Dr. van Loon said MNT that the special diet and fasting protocol was designed to “not affect the anabolic response to the next day’s protein ingestion.”
The researchers inserted a catheter into each participant’s upper arm for an amino acid infusion, which acted as a tracer to measure MPS rates. They also inserted a second catheter into the opposite arm for blood sampling to measure amino acid, insulin and glucose concentrations in the blood.
Young male participants trained on a seated knee extension machine and leg press with increasing loads.
After letting the subjects rest, the researchers took blood samples and performed muscle biopsies to determine MPS rates at rest and during exercise recovery.
Then, the researchers randomly assigned participants a drink with 30 g (about 2 1/2 tablespoons) of potato protein or milk protein. They followed it up with more blood draws and muscle biopsies.
The study concluded that “[…] Ingesting 30g of protein has been shown to strongly stimulate muscle protein synthesis during recovery from exercise, “said Dr. by Loon.
This double-blind study allowed the researchers to observe MPS in exercised and unexercised muscles. He also added to research showing how potato protein can promote exercise and recovery.
However, the current study also had several limitations.
The study sample size was quite small. Dr. van Loon acknowledged that “further dose-response studies in larger populations are undoubtedly needed[…]”
Furthermore, the trial only involved males. Researchers in a 2021 study warned that gender differences in physique, hormones and metabolism can make it difficult to apply the research from boys to girls.
Furthermore, the participants were young adults, whose anabolic resistance of skeletal muscle to protein ingestion may differ from that of older individuals. The research mentioned above mentioned, however, that older and younger male athletes may share similar protein metabolism.
As the market for protein supplements continues to expand, some researchers argue that these products pale in comparison to whole foods in terms of nutritional benefits.
Dr Stuart Phillips, Canada’s Tier 1 Research Professor and Chair in Kinesiology at McMaster University in Ontario, who was not involved in this study, believes that “[…]food trumps a supplement “.
In an interview with Auburn University, Dr. Phillips acknowledged that the greatest appeal of protein supplements is their convenience.
He pointed to his own study 2015 suggesting that people who get protein from food “have a higher density of nutrients in their diets”.