Low nutritional quality in many vegetarian meat substitutes — ScienceDaily

A food regimen largely made up of plant-based meals reminiscent of root greens, pulses, fruit and greens typically has a low local weather affect and can be related to well being advantages reminiscent of a diminished danger of age-related diabetes and heart problems, as has been proven in a number of giant research. But there have been far fewer research of how folks’s well being is affected by consuming merchandise primarily based on what are often known as textured* plant proteins.

In the brand new examine from Chalmers, a analysis workforce within the Division of Food and Nutrition Science analysed 44 completely different meat substitutes offered in Sweden. The merchandise are primarily manufactured from soy and pea protein, but additionally embrace the fermented soy product tempeh and mycoproteins, that’s, proteins from fungi.

‘Among these merchandise, we noticed a large variation in dietary content material and the way sustainable they are often from a well being perspective. In common, the estimated absorption of iron and zinc from the merchandise was extraordinarily low. This is as a result of these meat substitutes contained excessive ranges of phytates, antinutrients that inhibit the absorption of minerals within the physique,’ says Cecilia Mayer Labba, the examine’s lead creator, who not too long ago defended her thesis on the dietary limitations of switching from animal protein to plant-based protein.

The physique misses out on needed minerals

Phytates are discovered naturally in beans and cereals — they accumulate when proteins are extracted to be used in meat substitutes. In the gastrointestinal tract, the place mineral absorption takes place, phytates type insoluble compounds with important dietary minerals, particularly non-heme iron (iron present in plant meals) and zinc, which signifies that they can’t be absorbed within the gut.

‘Both iron and zinc additionally accumulate in protein extraction. This is why excessive ranges are listed among the many product’s components, however the minerals are certain to phytates and can’t be absorbed and utilized by the physique,’ says Cecilia Mayer Labba.

Iron deficiency amongst ladies is a widespread, international drawback. In Europe, 10 to 32 per cent of ladies of childbearing age are affected** and virtually one in three teenage women at secondary college in Sweden***. Women are additionally the group in society most probably to have switched to a plant-based food regimen and to eat the least quantity of crimson meat, which is the principle supply of iron that may be simply absorbed within the digestive tract.

‘It is evident that in terms of minerals in meat substitutes, the quantity that’s out there for absorption by the physique is a vital consideration. You can’t simply take a look at the listing of components. Some of the merchandise we studied are fortified with iron however it’s nonetheless inhibited by phytates. We consider that making diet claims on solely these vitamins that may be absorbed by the physique may create incentives for the trade to enhance these merchandise,’ says Ann-Sofie Sandberg, Professor of Food and Nutrition Science at Chalmers and co-author of the examine.

The meals trade wants new strategies

Tempeh, created from fermented soybeans, differed from the opposite meat substitutes within the quantity of iron out there for absorption by the physique. This was anticipated, because the fermentation of tempeh makes use of microorganisms that break down phytates. Mycoproteins stood out for his or her excessive zinc content material, with out containing any recognized absorption inhibitors. However, in response to the researchers, it’s nonetheless unclear how nicely our intestines can break down the cell partitions of mycoprotein and the way this in flip impacts the absorption of vitamins.

‘Plant-based meals is necessary for the transition to sustainable meals manufacturing, and there’s big improvement potential for plant-based meat substitutes. The trade wants to consider the dietary worth of those merchandise and to utilise and optimise recognized course of strategies reminiscent of fermentation, but additionally develop new strategies to extend the absorption of assorted necessary vitamins,’ says Cecilia Mayer Labba.

Production of plant proteins

• Most current plant-based protein merchandise available on the market are primarily based on protein extracted from a cultivated plant, reminiscent of soybeans, and separated from the plant’s different elements.
• The protein is then subjected to excessive strain and temperature, which restructures the proteins, often known as *texturization, so {that a} product will be achieved that’s meatier and chewier together with different components.
• Chalmers’ examine reveals that the dietary worth of meat substitutes out there right this moment is commonly poor relying on the selection of uncooked materials (usually imported soy) and processing situations (content material of anti-nutrients), and on components (fats high quality and salt).
• A meal containing 150 grams of meat substitutes contributes as much as 60 per cent of the utmost beneficial every day consumption of salt, which in response to the Nordic Nutrition Recommendations is 6 grams.

* The protein is restructured by excessive strain and temperature.

** Milman, Taylor, Merkel and Brannon: Iron standing in pregnant ladies and ladies of reproductive age in Europe. Am J Clin Nutr 2017; 106 (Suppl): 1655S-62S.

*** Riksmaten Adolescents Survey 2016-2017, Swedish National Food Agency (Livsmedelsverket) report sequence no. 23, 2018. Swedish National Food Agency (Livsmedelsverket) 2018.