Plant-based “meat” protein may be less well absorbed by the body than chicken breast protein

The proteins found in meat alternatives made from wheat and soy may be less well absorbed from the small intestine into the bloodstream than protein from chicken breasts.

Health


June 22, 2022

In a lab experiment, protein from a meat substitute (left) was not absorbed by intestinal cells, nor was protein from chicken breast (right).

Adapted from Journal of Agricultural and Food Chemistry 2022

Dietary protein from plant-based meat alternatives may not be absorbed as well as protein from chicken breast.

“This work opens a door to the nutritional properties of plant-based meat substitutes,” say Da Chen and Osvaldo Campanella, who led the research at Ohio State University. Chen is now based at the University of Idaho.

In their lab experiment, Chen, Campanella and their colleagues grew a layer of human intestinal cells on scaffolds that divided several dishes into two chambers. They then used stomach and small intestine enzymes to digest a plant-based meat alternative and cooked chicken breast, before adding each digested product to a chamber of each dish.

Next, the team measured the amount of protein fragments – or peptides – that passed through the intestinal cell layer to reach the opposite chamber in each dish, representing protein absorption through the gut.

Within four hours of addition to the dish, which is the longest typical transit time for food in the small intestine, approximately 2% less protein from the plant-based meat alternative had been transferred through intestinal cells, compared to chicken protein. Breast. Although this is a small percentage difference, statistical analysis suggests that this result was not a coincidence.

Eating meat substitutes can therefore lead to a decrease in the absorption of proteins by our intestinal wall into our bloodstream. The researchers did not assess whether this reduced absorption leads to protein deficiency.

In the second part of the experiment, the team analyzed peptides from digested food, finding that chicken breast protein fragments are smaller and more water soluble than meat alternative peptides.

“It has been shown that peptides of smaller size and more [solubility] can more easily transfer across [these gut] cells,” say Campanella and Chen.

However, the lab model is a highly simplified version of the intestine lacking the mucous membrane found in the body, they say.

“In the intestine, the peptides must pass through a layer of mucus… which acts as a filter… before reaching the cells of the intestinal epithelium. [We tested protein absorption] regardless of the mucus layer,” the couple explained.

Protein absorption may also differ in the large intestine, where food can stay for up to 24 hours, a period that was not assessed in the experiment.

Additionally, protein absorption from plant-based meat alternatives and other meats beyond chicken breast depends on their composition and transformation into individual proteins.

Despite their findings, the team argues that plant-based meat substitutes are likely a good source of protein.

“Even though the plant-based meat substitutes had fewer peptides absorbed, they still provide a good amino acid profile and could be an adequate addition to a well-balanced diet,” Campanella and Chen say.

Researchers are now working to improve the nutrition absorbed from plant-based meat substitutes.

“Plant-based foods must be carefully designed to ensure they have similar or better nutrient profiles than animal-based ones,” says David Julian McClements of the University of Massachusetts Amherst.

Journal reference: Journal of Agricultural and Food Chemistry DOI: doi.org/10.1021/acs.jafc.2c01711

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