Study finds low nutritional quality in many vegetarian meat substitutes

A recent Swedish study found that the absorption levels of iron and zinc from many meat substitutes were significantly lower than real meat.

The study was published in the journal, Nutrients, and led by Inger-Cecilia Mayer Labba, a doctoral student at Chalmers University of Technology in Gothenburg, Sweden. Although previous studies have shown an association between plant-based foods and health benefits like reduced risk of age-related diabetes and cardiovascular disease, few studies have analyzed the health effects of textured plan proteins, or meat substitutes. For this investigation, Labba and her colleagues sought to better understand the nutritional value of meat substitutes and how well the body is able to absorb their nutrients.

Researchers analyzed 44 different meat substitutes sold in Sweden. The products were made mostly from soy, pea protein, and proteins from fungi.

“Among these products, we saw a wide variation in nutritional content and how sustainable they can be from a health perspective,” said Labba. “In general, the estimated absorption of iron and zinc from the products was extremely low. This is because these meat substitutes contained high levels of phytates, antinutrients that inhibit the absorption of minerals in the body.”

Phytates, found naturally in beans and cereals, are accumulated during the extraction process of the proteins used for meat substitutes. These antinutrients form insoluble compounds with essential dietary minerals like zinc and iron and prevent the nutrients be absorbed by the intestine.

The meat substitute, tempeh, made from fermented soybean, differed from the other plant proteins. Scientists found the microorganisms involved in the fermentation process broke down phytates and allow for better absorption of nutrients. In addition, mycoproteins stood out as they had a high zinc content and no known absorption inhibitors. However, according to the researchers, it’s still unclear how well the human intestine can break down the walls of mycoproteins, and it may affect nutrient absorption.

“Plant-based food is important for the transition to sustainable food production, and there is huge development potential for plant-based meat substitutes,” said Labba. “The industry needs to think about the nutritional value of these products and to utilise and optimise known process techniques such as fermentation, but also develop new methods to increase the absorption of various important nutrients.”