The Role of Meat in the Human Diet
Nowadays, a meat-free diet is becoming increasingly popular among humas. The data of the Polish Central Statistical Office show that in 2020 meat consumption in Poland per capita was 76.9 kg, while in 2021 it was only 60 kg. This situation might be caused by the spreading wave of false information regarding the condition of slaughtering animals. What a statistical consumer can see is meat packed in an airtight package on a refrigerated store shelf. Nevertheless, they cannot see the slaughter of animals nor do they know what stages it consists of and in what conditions it is done. Consequently, it is effortless for people who care about less meat consumption in society to manipulate the consumer by sending them false information related to slaughter. Poland has in force the Regulation of the Ministry of Agriculture and Rural Development of 9 September 2004 on the qualifications of persons entitled to professional slaughter, as well as on the conditions and methods of slaughter and killing animals, which protects animals sent for slaughter [1]. Those who endorse the vegetarian diet argue that meat may harm our health.
Some History
The history of human existence began about 7 million years. A man of the species Homo sapiens (Latin: “wise man”) appeared on earth about 200-180 thousand years ago. Man’s ancestors, while travelling across Africa, began to enrich their diet with meat. This contributed to the intensification of human evolution. The brain underwent the greatest development. Meat became a source of energy that was necessary for social and intellectual development. Unlike plant sources, meat was a rich reservoir of energy. During the Ice Age, meat made up more than 50% of the diet. Studies conducted by Colorado State University also confirmed that meat products represented as much as two-thirds of the food consumed by the human hunter-gatherer population [2]. There are several arguments in favour of the evolutionary adaptation of the human body to the meat diet. One argument is that the human pancreas produces collagenase. This enzyme is responsible for the breakdown of collagen, namely a component of the extracellular matrix of animal tissues [3].
What is in the Meat?
Meat contains protein, fat, carbohydrates, and numerous minerals. Proteins are the building blocks of cells and tissues. They ensure the proper functioning of the entire body. If we provide too little protein to our body, then the formation and activity of enzymes are inhibited. Not only do they affect the rate of epidermis regeneration and the growth of hair and nails, but they also maintain an acid-base balance. Proteins include amino acids. We can single out exogenous and endogenous amino acids. Exogenous amino acids ensure the production of hormones, the proper functioning of the nervous system, proper muscle function, and metabolism. The human body is unable to synthesise exogenous amino acids such as methionine, lysine, and valine. Accordingly, they must be supplied with food. Not every protein is wholesome, and if this is the case, it does not contain all the exogenous amino acids in the right amounts and in the right ratio. The wholesome proteins include the proteins to be found in the meat, while the incomplete protein is, for instance, the protein to be found in cereal products [3].
As far as the minerals found in meat are concerned, the presence of well-absorbed heme iron is of importance. Iron is a valuable element because of its role in transporting oxygen and delivering it to the muscles and all organs. It is also essential to the proper functioning of the nervous system and the immune system. Meat contains up to 45% heme iron, while the remaining part of the total iron content is its non-heme counterpart. The digestibility of heme iron is 35% when the absorption of its non-heme counterpart reaches a maximum of 20%. Products of plant origin do not contain an easily digestible form of the valuable element [4]. Zinc present in meat is essential in the synthesis of insulin and is involved in the synthesis of enzymes. Meat and meat products in general are also a source of calcium and phosphorus compounds. Calcium-containing substances are the building material of bones and enamel.
Yet another important ingredient to be found in meat is laevorotatory carnitine. It is a biologically active substance, the greatest amounts of which are found in the meat of ruminants. Human body does not synthesise carnitine in an appropriate amount, therefore 75% should be delivered with the diet. L-carnitine derived from meat features the highest bioavailability, and this results in a significant increase in the nutritional value of meat products. This substance is involved in lipid metabolism. As a result, it contributes to lowering the level of triacylglycerols and cholesterol in our blood. Since it causes the formation of ester links, it significantly contributes to the removal of xenobiotics – harmful substances. Further, L-carnitine reduces the amount of lactic acid produced in the muscles and thus improves the exercise capacity of the human body. Meat in the human diet is a richer source of carnitine (102.6 mg/100 g) than milk (8.5 mg/100 ml), while its bioavailability is much greater – 0.78 from meat vs 0.26 from milk [5].
Meat products provide some vitamins. Beef meat is a good source of vitamin B12. Animal products are the only source of vitamin B12 as plants lack it. The functions of this substance are many-fold. It is responsible for the conversion of ribonucleotides and prevents the development of malignant anaemia. In addition to vitamin B12, meat contains significant amounts of vitamin B6 (responsible for the transformation of amino acids), as well as vitamin B9 (folic acid) and B5. Deficiencies of these vitamins lead to changes in the blood. Meat from slaughter animals supplies vitamin B1 (riboflavin) and vitamin B2 (thiamine), whose deficiencies are detrimental to the human body. Riboflavin deficiency inhibits the growth of the body, and thiamine deficiency leads to a disease called beriberi, which manifests itself in disturbances in the functioning of the nervous system and heart function, as well as in muscle atrophy [6].
Despite the beneficial substances found in meat, consumers often happen to list fat as a negative component that contributes to the development of cardiovascular disease. However, it should be noted that fat affects human health through the action of fatty acids, sterols and vitamins soluble in it. The fat content depends on environmental and genetic factors. It can be changed by appropriate selection of animal breeds and modification of the feed composition [7].
Nutritionists vs WHO Experts
Nutritionists recommend limiting the consumption of fatty meat. WHO/FAO experts are of a different opinion and believe that our diet should be balanced. Only this form of nutrition can prevent the further development of civilisation diseases.
AUTHORS:
- Piotr Włodawiec – partner, legal counsel
- Anna Pakulska – food technology engineer