This article is taken from the monthly journal Sciences et Avenir – La Recherche #901 of March 2022.
This is a real symbol: in 2021, the famous fast food brand McDonald’s launched its McPlant burger, which instead of the traditional ground beef steak was a pancake made of peas, rice and potatoes. An opportunistic way to respond to declining meat consumption in Western countries. In France, this has increased from an average of 90 kg per person in 2002 to 84.5 kg in 2020, according to France Agrimer. A stern passage with multiple motives: the desire to save the planet, taking into account the welfare of animals and, of course, their health.
You should eat less meat
Reducing meat consumption at the global level would be an effective solution to reduce greenhouse gas emissions responsible for climate change. The Inrae Montpellier team simulated the environmental impact of the contents of our plate. Verdict in numbers.
Credit: Bruno Bourgeois
Their training is questionable.
Health authorities are indeed calling for a reduction in the consumption of red meat (no more than 500 grams per week) and cold cuts (no more than 25 grams per day per adult), which are blacklisted by the World Health Organization (WHO). , in humans, have classified them as “probable carcinogen” and “proven carcinogen” respectively, mainly in colorectal cancer. It is in this context that manufacturers have developed an alternative to “plant substitutes”. Sliced into sausages, meatballs, nuggets or even rolls, the plant has conquered supermarket shelves in a few years, as well as the menu of 100% vegan restaurants. Appearance, texture, taste…
These ready-to-cook foods typically mimic “real” ground beef steak or breaded chicken, thanks to the use of legumes (beans, soy, peas, lentils) and grains (rice, wheat), the main sources of vegetable protein. . A good point is noted by nutritionists who note that the French consume little. “The National Healthy Nutrition Program (PNNS) recommends a ratio of 50% protein intake from animal sources to 50% from plant sources, emphasizes Stéphane Valran, director of research at the Human Nutrition Laboratory at Inrae in Clermont-Ferrand. But we’re in the wrong place: in France we still consume two thirds of animal proteins and one third of vegetable proteins.
But everything is more difficult. A plant product by itself does not provide the nine amino acids that make up the proteins the body needs for muscle, enzyme synthesis, antibodies, and hormones. Legumes are deficient in methionine and cysteine, explains Stephane Valran. Therefore, care must be taken to combine low lysine cereals with legumes to ensure good nutritional quality. However, this is not always the case, even if manufacturers are working on source complementarity. “Added to the problem of quality is the problem of quantity: industrial meat substitutes may not be enough. “Less than 15 g of protein per 100 g of product does not meet the daily requirement. (0.83 g/kg body weight, i.e. 58 g for a 70 kg person, Ed),” notes Florence Foucault, a dietitian-nutritionist based in Paris. In addition, the use by industrialists of proteins in the form of peptides (hydrolysates) of legumes and grains reduces their nutritional value. “Finally, we lose dietary fiber, vitamins and minerals. It’s also a good idea to make yourself pancakes with legumes and grains to reap all of their nutritional benefits. “, says Jean-Michel Lecerf, head of nutrition at the Pasteur Institute in Lille.
Plant substitutes also raise the question of their preparation. Indeed, industrial processes can increase the amount of isoflavones (genistein and daidzein) present in soy. However, they are called “phytoestrogens” because of their ability to bind to the female hormone receptor, estrogen, and can interfere with cell function and play an inhibitory or activating role depending on the organ where they bind and their focus. “Textured soy protein, derived from crushed, defatted seeds and used in the manufacture of patties, contains more isoflavones than raw seeds. “, – confirms Catherine Bennetau-Pelicero, Professor of Nutrition and Health at the University of Bordeaux. In a recent study, she measured the level of isoflavones in 140 commercial products containing soy. Result: a 100 g soy steak can contain up to 40 mg. “It can do a lot for a child knowing that the National Food Safety Authority (ANSES) recommends not exceeding 1mg of isoflavones per kilogram of body weight and per day, which is 60mg for a 60kg adult. “, notes the researcher. Therefore, she regrets that the content of phytoestrogen is not mentioned on the packaging, as, however, the health authorities recommended in 2005. “Vegetable soy pancake can be eaten from time to time, but not every day. “, she concludes.
Faced with vegetable restrictions, the growth of cultivated meat
By carefully examining the list of ingredients, we also find that these products, which are marketed as being healthier, in fact often sin on a nutritional level. “In order to enhance the palate — the palatability — of soybeans and lentils, manufacturers add salt, sugars (glucose syrup, maltodextrin) and fats. Therefore, we must remain vigilant and avoid those containing more than 10% lipids, especially if they are saturated fatty acids such as palm oil or partially hydrogenated fats (trans fatty acids), which are harmful to the cardiovascular system. “explains Florence Foucault. Vigilance should not stop there. Also beware of the various additives (texturizers, dyes) present to deceive. “Meat substitutes are added to the list of ultra-processed foods already consumed every day. Eating them twice a week is enough “, advises Jean-Michel Lecerf.
– Plant protein intake provided by wheat, soy, lentils, etc.
– Ready to cook.
– Ultra-processed products with the presence of various additives.
– Variable levels of protein, sugar, salt and fat.
– Use of protein hydrolysates or textured proteins that reduce fiber, minerals and vitamins.
– High content of isoflavones in soy substitutes.
Finally, plant-based alternatives do not replace the nutritional quality of meat, which also contains zinc, an immune system stimulant involved in neurological function and activating skin repair. As well as vitamin B12, necessary for the normal functioning of the nervous system and the formation of red blood cells, but absent in the plant kingdom, or even iron (called heme), which is absorbed better than that present in plants. Therefore, plant-based steak lovers will have to look elsewhere for these nutrients: in seafood, eggs, or oilseeds (walnuts, hazelnuts, almonds).
Faced with all these limitations of industrial meat alternatives, start-ups have set about developing cultured meats. Long confined to research labs, it got its first green light in 2020 in Singapore, where American startup Eat Just can sell its lab-grown chicken nuggets to restaurants. Since then, the company plans to build an artificial meat plant in Qatar by 2023, as do several other companies such as Future Meat Technologies, which has already launched its plant near Tel Aviv in Israel, or Upside Food, California (USA). ). If this cultured meat is currently out of fashion in France, it raises many questions, both ethical and nutritional (see box below).
“The safety of artificial meat for health has not been proven” – Jean-Francois Oquette, Researcher at the Joint Herbivore Research Group, INRAe de Clermont-Ferrand.
“Making artificial “meat” requires solving certain problems. To stimulate the reproduction and differentiation of stem cells, fetal calf serum obtained from fetal blood is used. To collect it requires the killing of a cow and her calf. startups say they managed to get rid of the use of this serum, but no one explains how. Nevertheless, this is an important point, confirming that the process allows you to kill fewer animals. In addition, these companies will use hormonal growth promoters that are banned from breeding in the European Union. This will create a problem for the marketing of their product in Europe. Finally, no scientific study guarantees that the final food product meets health safety requirements and our needs. in nutrition. Produced muscle fibers will be rich in protein, but poorer in iron and vitamin B12 than farm-raised meat. sist to add anything that might be missing. This will lead to the further development of ultra-processed products. ”