- What are proteins?
- Health benefits of proteins
- What are the main protein sources?
- Health consequences of excessive protein intake
Our body needs proteins, as they are found in all the cells of our body and are essential for our bones, muscles, and skin to remain healthy and, in short, for us to enjoy a proper state of health.
These proteins that are in our cells are formed by amino acids, which are the pieces of the “puzzle” that end up making up a complete protein. And it is through our diet that we must obtain these amino acids.
The easiest way to obtain the necessary amino acids is through the consumption of animal proteins since they contain all the amino acids that our body is not able to produce. Some vegetables are also a source of protein, but they do not usually have all the necessary amino acids, so there may be more problems.
In this article we will answer some of the most common questions about proteins: where can we get them from? is it bad to eat meat? which vegetables are a source of amino acids? what happens if we eat too many?
What are proteins?
Proteins are molecules made up of other smaller components called amino acids, which are joined together to form a chain and give rise, depending on their sequence, to the protein itself.
Proteins form the muscles of animals, which is why the best way to introduce amino acids into our body to then renew the tissues is by ingesting animal meat or its products, which are also rich in proteins.
Proteins, then, are nutrients because once introduced into the body, we are able to digest them, break them down into smaller units, and use them to renew our muscle, bone, and epithelial tissues. Proteins are the building material of our body.
Although they are not the body’s main source of energy, they are one of the most important sources of matter. These nutrients are basic to repair any tissue and organ of the body, renew cells, and allow the correct growth and development of the body, both physically and mentally.
Health benefits of proteins
There are many different proteins and each of them has a very specific function within the body. According to PubMed.gov, proteins should represent approximately 12% of the daily caloric intake. Therefore, including protein foods in the diet is essential since, in addition to obtaining essential amino acids through them, they fulfill the following functions in the body:
1.- Organ and tissue maintenance
Proteins are part of all body structures. They provide elasticity and resistance to all the organs and tissues of our body, as well as being the main supply to renew and repair them when there is damage or by the simple process of aging.
The muscles, and not only the mechanical ones, but also the heart, the brain, or the lungs; the bones, the tendons, the skin, the nails, the hair, etc, all these components of our organism would not work properly nor would they be in good conditions without the necessary contribution of proteins.
2.- Regulation of metabolism
Proteins can also function as enzymes, molecules that act by accelerating all the metabolic reactions that take place in our body.
3.- Molecule transport
Proteins act as “transporters” of other molecules. They are responsible for transporting oxygen through the body, fats, glucose, and amino acids into the different cells of the organism.
4.- Source of energy
Proteins are not the body’s preferred source of energy because, unlike carbohydrates or fats, they cannot be stored. However, they are also a source of energy, which is especially important when there is a carbohydrate deficit in the diet, as the body can “dip into” the calories from proteins.
5.- The immune and endocrine system
Proteins are an indispensable part of the antibodies so without them the actions of the immune system of recognition and subsequent neutralization of pathogens cannot take place correctly. In addition, they also constitute hormones, which have implications in the control and regulation of innumerable physiological, metabolic and structural processes of our organism.
What are the main protein sources?
The most complete sources of proteins are, without a doubt, the products of animal origin. However, as we will see below, there are different plant foods that can also represent, although not in such quantity or variety, a good source of amino acids.
Meat is one of the main protein foods since its protein composition is about 20% and, whatever the animal, it offers all the necessary amino acids. In addition, meat is the best source of both vitamin B12 and iron. The main problem is that at least red meat has relatively high amounts of fat.
As for the differences between white and red meat, it is worth noting that, despite sometimes hearing the contrary, red meat does not have more protein than white meat. That is to say, chicken or turkey meat provides the same amount of amino acids as beef, veal, or lamb.
It is important to bear in mind that proteins are damaged by heat, so some are lost during cooking. Therefore, the less the piece of meat is cooked, the more protein it will have. But this already depends on the consumer’s taste.
Fish is the second source of protein par excellence since we are eating directly the muscle of an animal, which means that the contribution in the form of proteins is also approximately 20%.
In addition to providing practically the same proteins like meat, fish has more health benefits than meat. Therefore, fish is surely the best source of proteins that exists.
Fish is a great food group that we can take advantage of. From them, we can obtain this and other quality nutrients such as omega 3 fats, vitamin D, and various minerals.
Oily fish, or those with the highest fat content, are at the same time the ones that usually offer us the most protein and among them, the ones that offer us the most protein are tuna, anchovies, salmon, or mackerel.
Eggs are one of the best sources of amino acids since their composition contains 14% of protein, which, by the way, is of enormous quality and very easily digestible, offering us all the essential amino acids in the right quantities.
It should be noted that, contrary to what it might seem, practically all the protein content of the egg is in the egg white. The yolk of the egg has few amino acids but is very rich in fat and cholesterol, so it is recommended to eat only about 3 eggs a week. If you only want to eat the white, you could eat it without problems every day.
4.- Dairy products
The proteins present in milk and dairy products do have a high biological value, but the problem is that they are not present in large quantities. Proteins make up only 3% of milk, so it is difficult to obtain the minimum requirements from them.
In any case, milk and dairy products such as cheese or yogurt, as long as you try to buy those versions with less fat, are an excellent source of quality proteins that perfectly complement the amino acids of other foods.
Legumes have a very high amount of amino acids, in fact, they have more than meat or fish, since up to 25% of their composition are proteins. The problem is that these are not as high quality as the previous foods, since they do not provide all the essential amino acids.
To achieve the protein levels that would be obtained with a single fish, several different types of legumes should be consumed. And it should be borne in mind that this may involve a significant caloric intake. Certainly much higher than eating a piece of fish or meat.
6.- Nuts and dried fruits
Nuts are very interesting in vegetarian and vegan diets, as they represent a good supply of protein of quality not as high as that of animal origin but which can meet the requirements well. The amount of protein in these nuts varies greatly, but it does tend to be high.
The problem is that they are also high in calories and high in fat, so they should be consumed in moderation. In any case, they are one of the best alternatives to meat in terms of obtaining amino acids.
Health consequences of excessive protein intake
The benefits of protein and the need to include it in the diet are clear. The problem is that in today’s society, especially in more developed countries, we consume much more protein than our body needs.
However, it should be noted that the harmful effects of excessive protein consumption are still not very clear. There is still much controversy as to whether exceeding the recommended limits of consumption really affects our health.
Some studies hypothesize that high-protein diets may damage bone metabolism and even affect the kidneys, but more research is still needed. Moreover, this is only the case if the excess of protein is enormous, values in which the average population is never found.
Therefore, there is no need to worry about excess protein. The problem is what accompanies these proteins in the food. That is to say, eating a lot of red meat is not bad because of the proteins themselves, but because it is also rich in fats. What harms health is the “bad” fats, not the proteins in the meat.