By Reed Mangels, PhD, RD
While waiting for my turn at the DMV, I noticed a story about plant-based meats on their television screen. The headline said something like “Study Reveals Plant-Based Meats Not As Nutritious As The Real Deal.”
I looked into the research, conducted at Ohio State University, which this story was based on. Basically, researchers created a meat alternative from soy and wheat gluten. They cooked pieces of the plant-based meat and pieces of chicken meat, ground them up, and digested them using an enzyme that mimicked the human digestive process. In other words, both the chicken and plant-based meats underwent something that was similar to what happens in our stomachs. The researchers then used human cells to measure how well the digested proteins from chicken meat/plant-based meat were absorbed.
The proteins in the meat analog were not digested to the same extent as were the proteins in the chicken breast. In protein digestion, protein, which are chains of amino acids, are digested to shorter chains of protein called peptides. The peptides are then digested to amino acids. After digestion, there were more small peptides from the chicken breast than from the meat analog indicating that proteins from the chicken breast were better digested. Peptides from the chicken breast were more quickly absorbed. More essential amino acids from the chicken breast were absorbed by human cells compared to amino acids from the meat analog.
It does not seem possible to extrapolate from these results to what would happen in the human body, so we can’t say x% of the amino acids in a meat analog is absorbed compared to y% of the amino acids from a chicken breast. Although fewer essential amino acids were absorbed from the meat analog, essential amino acids were absorbed which would then be used to create necessary protein in the body.
The relatively small difference in protein digestion and absorption from a meat analog compared to chicken that was seen in this study does not seem important if we look at the bigger picture. People eating enough calories and a variety of healthy foods get enough protein. Most people in the United States, whether nonvegetarian, vegetarian, or vegan, get plenty of protein. Replacing meat products with plant-based alternatives will not lead to widespread protein deficiency.
In some ways, the results of this study are not surprising. Wheat gluten, which was used in the meat analog along with soy protein, is known to be less digestible than either soy or animal protein. Had the researchers altered the ratio of soy protein to wheat gluten in the meat analog, the results may have been different. The researchers did not test commercially available plant meats which may contain ingredients that affect digestion and absorption, either positively or negatively.
We also don’t know if digestion and absorption would be different if it was studied in humans instead of in human cells. Could it be possible that people adapt to plant proteins and are better able to digest and absorb them with time?
All I can conclude from this study is that more research is needed. It seems premature to say, as the headline that originally caught my eye did, that plant meats are not as nutritious as animal meats. In my opinion, this is wording that was chosen for its sensationalism, but the actual study is nothing to get excited about.
Reference
Chen D, Rocha-Mendoza D, Shan S, et al. Characterization and cellular uptake of peptides derived from in vitro digestion of meat analogues produced by a sustainable extrusion process. J Agric Food Chem. 2022;70(26):8124-8133.
To read more about plant meats see:
How Do the Newer Meat-Like, Plant-Based Burgers Compare Nutritionally?
Plant-based Alternative “Meats”
How Many Consumers Purchase Plant-based Meat, Milk, or Dairy in 2019?