Many of the meat substitutes sold in Sweden claim to be high in iron, but in a form that cannot be absorbed by the body.
The availability of plant-based protein foods that can replace meat has increased dramatically as more and more people choose a plant-based diet. At the same time, there are many challenges regarding the nutritional value of these products. A study by Chalmers University of Technology in Sweden shows that many of the meat substitutes sold in Sweden claim to be high in iron and zinc, but in a form that can’t be absorbed by the body.
A diet composed largely of plant-based foods, such as root vegetables, legumes, fruits and vegetables, generally has a low impact on climate and is also associated with health benefits, such as reduced risk of climate-related diabetes. age and cardiovascular disease, as has been demonstrated in several large studies. However, far fewer studies have been conducted on how people’s health is affected by the consumption of products based on so-called textured vegetable proteins. In Chalmers’ new study, a research team from the Division of Food and Nutrition Sciences analyzed 44 different meat substitutes sold in Sweden. The products are mainly made with soy and pea proteins, but also include tempeh , a fermented soy product, and mycoproteins , i.e. mushroom proteins.
“In general, the estimated uptake of iron and zinc from 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,” explains Cecilia Mayer Labba, lead author of the study.
Phytates occur naturally in beans and grains – they build up when protein is extracted for use in meat substitutes. In the gastrointestinal tract, where mineral absorption occurs, phytates form insoluble compounds with essential dietary minerals, particularly non-heme iron (the iron found in plant foods) and zinc, meaning they cannot be absorbed into the gastrointestinal tract. ‘intestine. Both iron and zinc also accumulate in protein extraction. For this reason, high levels are indicated among the ingredients of the product, but the minerals are linked to the phytates and cannot be absorbed and used by the body”, explains Cecilia Mayer Labba.
The food industry needs new methods
So some of the products under study are enriched in iron, which however is still inhibited by phytates. We believe that nutrition claims only for nutrients that can be absorbed by the body can incentivize industry to improve products,” says Ann-Sofie Sandberg, professor of food and nutrition science at Chalmers and co-author of the study. Tempeh, made from fermented soybeans, differs from other meat substitutes in the amount of iron available for the body to absorb. This was expected, as the fermentation of tempeh uses microorganisms that break down phytates. Mycoproteins were distinguished by their high zinc content, without containing any known uptake inhibitors. However, according to the researchers,
“Plant-based foods are important for the transition to sustainable food production and the development potential for plant-based meat substitutes is enormous. The industry has to think about the nutritional value of these products and use and optimize known process techniques, such as fermentation, but also develop new methods to increase the absorption of various important nutrients,” says Cecilia Meyer Labba.
- Nutritional Composition and Estimated Iron and Zinc Bioavailability of Meat Substitutes Available on the Swedish Market (mdpi.com)