Meat and meat-based substitutes vary widely in their nutritional content

Plant-based meat substitutes are similar to real beef in their chew and taste, along with the 13 nutritional items listed on their labels, like proteins, vitamins, and fats, making them appear essentially equivalent to meat.

A juicy beef burger, or is it? Image Credit: Guilhem Vellut via Wikimedia Commons.

However, a research team from Duke University deeply examined the nutritional content of plant-based meat alternatives, with the help of “metabolomics”—an advanced science tool—and the results showed that meat and meat alternatives vary widely.

Plant-based meat products are made meaty by manufacturers by adding leghemoglobin, an iron-carrying molecule from soy, berries, red beet, and carrot extracts to simulate bloodiness. The near-meat texture is attained by adding indigestible fibers like methylcellulose.

To make up for the protein levels of meat, manufacturers used isolated plant proteins from peas, soy, and other plant sources in the plant-based meat alternatives. Certain meat substitutes also had vitamin B12 and zinc to further mimic meat’s nutrition.

According to the study results published in Scientific Reports, there are many more nutritional components that are not listed on the labels, and that makes these products widely different from meat.

The metabolites that the researchers measured are building blocks of the body’s biochemistry and they play a crucial role in cell signaling, energy conversion, building and tearing down structures, and other functions.

It is anticipated that there are over 100,000 of these molecules in biology and half of these metabolites circulating in human blood are considered to be derived from regular diets.

To consumers reading nutritional labels, they may appear nutritionally interchangeable. But if you peek behind the curtain using metabolomics and look at expanded nutritional profiles, we found that there are large differences between meat and a plant-based meat alternative.”

Stephan van Vliet, Postdoctoral Researcher, Duke Molecular Physiology Institute, Duke University

Around 18 samples from a popular plant-based meat alternative and 18 grass-fed ground beef samples from a ranch in Idaho were compared at the Duke Molecular Physiology Institute’s metabolomics core lab.

The investigation of the 36 carefully cooked patties showed that 171 out of the 190 metabolites they measured varied between beef and the plant-based meat substitute.

The beef contained 22 metabolites that the plant-based substitute did not have, and the plant-based substitute contained 31 metabolites that meat did not have. Greater differences were found in dipeptides, amino acids, phenols, vitamins, and types of saturated and unsaturated fatty acids.

Beef contained various metabolites important for human health, like spermine, creatine, cysteamine, anserine, squalene, glucosamine, and omega-3 fatty acid DHA. “These nutrients have potentially important physiological, anti-inflammatory, and or immunomodulatory roles,” the researchers noted.

These nutrients are important for our brain and other organs including our muscles. But some people on vegan diets (no animal products), can live healthy lives—that’s very clear.”

Stephan van Vliet, Postdoctoral researcher, Duke Molecular Physiology Institute, Duke University

However, plant-based substitutes contained beneficial metabolites like phenols and phytosterols not found in beef.

“It is important for consumers to understand that these products should not be viewed as nutritionally interchangeable, but that’s not to say that one is better than the other,” stated van Vliet, a self-described omnivore who relishes a plant-rich diet while also eating meat.

Plant and animal foods can be complementary because they provide different nutrients.”

Stephan van Vliet, Postdoctoral researcher, Duke Molecular Physiology Institute, Duke University

According to van Vliet, further investigation can help identify the short-term or long-term effects of the presence or absence of specific metabolites in meat and plant-based meat alternatives.