Cultured meat safety: Unlike conventional meat, cultured muscle cells may be safer, without any adjacent digestive organs; but with this high level of cell multiplication, some dysregulation is likely as happens in cancer cells

The Myth of Cultured Meat: A Review. Sghaier Chriki and Jean-François Hocquette. Front. Nutr., February 7 2020. https://doi.org/10.3389/fnut.2020.00007

Abstract: To satisfy the increasing demand for food by the growing human population, cultured meat (also called in vitro, artificial or lab-grown meat) is presented by its advocates as a good alternative for consumers who want to be more responsible but do not wish to change their diet. This review aims to update the current knowledge on this subject by focusing on recent publications and issues not well described previously. The main conclusion is that no major advances were observed despite many new publications. Indeed, in terms of technical issues, research is still required to optimize cell culture methodology. It is also almost impossible to reproduce the diversity of meats derived from various species, breeds and cuts. Although these are not yet known, we speculated on the potential health benefits and drawbacks of cultured meat. Unlike conventional meat, cultured muscle cells may be safer, without any adjacent digestive organs. On the other hand, with this high level of cell multiplication, some dysregulation is likely as happens in cancer cells. Likewise, the control of its nutritional composition is still unclear, especially for micronutrients and iron. Regarding environmental issues, the potential advantages of cultured meat for greenhouse gas emissions are a matter of controversy, although less land will be used compared to livestock, ruminants in particular. However, more criteria need to be taken into account for a comparison with current meat production. Cultured meat will have to compete with other meat substitutes, especially plant-based alternatives. Consumer acceptance will be strongly influenced by many factors and consumers seem to dislike unnatural food. Ethically, cultured meat aims to use considerably fewer animals than conventional livestock farming. However, some animals will still have to be reared to harvest cells for the production of in vitro meat. Finally, we discussed in this review the nebulous status of cultured meat from a religious point of view. Indeed, religious authorities are still debating the question of whether in vitro meat is Kosher or Halal (e.g., compliant with Jewish or Islamic dietary laws).

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Health and Safety

Advocates of in vitro meat claim that it is safer than conventional meat, based on the fact that lab-grown meat is produced in an environment fully controlled by researchers or producers, without any other organism, whereas conventional meat is part of an animal in contact with the external world, although each tissue (including muscles) is protected by the skin and/or by mucosa. Indeed, without any digestive organs nearby (despite the fact that conventional meat is generally protected from this), and therefore without any potential contamination at slaughter, cultured muscle cells do not have the same opportunity to encounter intestinal pathogens such as E. coli, Salmonella or Campylobacter (10), three pathogens that are responsible for millions of episodes of illness each year (19). However, we can argue that scientists or manufacturers are never in a position to control everything and any mistake or oversight may have dramatic consequences in the event of a health problem. This occurs frequently nowadays during industrial production of chopped meat.

Another positive aspect related to the safety of cultured meat is that it is not produced from animals raised in a confined space, so that the risk of an outbreak is eliminated and there is no need for costly vaccinations against diseases like influenza. On the other hand, we can argue that it is the cells, not the animals, which live in high numbers in incubators to produce cultured meat. Unfortunately, we do not know all the consequences of meat culture for public health, as in vitro meat is a new product. Some authors argue that the process of cell culture is never perfectly controlled and that some unexpected biological mechanisms may occur. For instance, given the great number of cell multiplications taking place, some dysregulation of cell lines is likely to occur as happens in cancer cells, although we can imagine that deregulated cell lines can be eliminated for production or consumption. This may have unknown potential effects on the muscle structure and possibly on human metabolism and health when in vitro meat is consumed (21).

Antibiotic resistance is known as one of the major problems facing livestock (7). In comparison, cultured meat is kept in a controlled environment and close monitoring can easily stop any sign of infection. Nevertheless, if antibiotics are added to prevent any contamination, even occasionally to stop early contamination and illness, this argument is less convincing.

Moreover, it has been suggested that the nutritional content of cultured meat can be controlled by adjusting fat composites used in the medium of production. Indeed, the ratio between saturated fatty acids and polyunsaturated fatty acids can be easily controlled. Saturated fats can be replaced by other types of fats, such as omega-3, but the risk of higher rancidity has to be controlled. However, new strategies have been developed to increase the content of omega-3 fatty acids in meat using current livestock farming systems (23). In addition, no strategy has been developed to endow cultured meat with certain micronutrients specific to animal products (such as vitamin B12 and iron) and which contribute to good health. Furthermore, the positive effect of any (micro)nutrient can be enhanced if it is introduced in an appropriate matrix. In the case of in vitro meat, it is not certain that the other biological compounds and the way they are organized in cultured cells could potentiate the positive effects of micronutrients on human health. Uptake of micronutrients (such as iron) by cultured cells has thus to be well understood. We cannot exclude a reduction in the health benefits of micronutrients due to the culture medium, depending on its composition. And adding chemicals to the medium makes cultured meat more “chemical” food with less of a clean label.