Similar to any other protein, collagen breaks down in the digestive system upon ingestion. However, economic interests and a lack of scientific research that is independent of the manufacturers allows the supplements market to thrive.

Collagen is probably the most common protein in the animal world. It is solely responsible for about four percent of our body weight. If we were to join all the collagen fibers in our body, their length would reach about one hundred trillion (1014) meters—a distance so great that if we tried to cross it at the speed of light, the endeavor would take us almost four days. 

In recent years, the popularity of collagen containing dietary supplements has been on the rise. Collagen is indeed a very impressive protein, but do we really need it as a dietary supplement? To answer this, we must understand what collagen does in our body and how it is produced.

What Is Collagen?

It’s no coincidence that collagen is so common in our body, since it is responsible to a large extent for the integrity of our body and the strength of our tissues. This is because collagen is the main building block of the extracellular matrix - the collection of fibers, enzymes and sugars responsible for connecting together all the cells of the body and for providing the tissues with structural support, a substrate for growth and more. The role of collagen in this matrix is more or less analogous to the role fulfilled by steel rods in concrete in modern buildings. In reality, collagen fibers can be 5–10 times stronger than steel, and can withstand stretching of up to half their length without tearing. 

Similar to many other proteins, collagen fibers are built from smaller protein chains. These chains twist together in the form of a triple helix that consists of three units of collagen, and the helices are twisted together into very strong braids. Although the length of the basic units is 330 nanometers (billionths of a meter), the length of a single collagen fiber can reach several millimeters - a huge size for a single molecule.

Collagen is found in all tissues of the body, but its concentration is particularly high in tissues that require significant structural strength, such as the skin, bones, teeth, tendons, muscles and blood vessels. Because of its role in these tissues, it’s no wonder that collagen is intimately involved in damage repair processes. For example, when we have a skin wound, collagen fibers will be cut and reorganized to repair the affected tissue. 

Nevertheless, the repair process is not free of mishaps, and accumulation of excess collagen in the skin may leave a scar. In internal organs, accumulation of collagen may lead to a condition called fibrosis, where, similar to a scar, collagen fibers displace healthy tissue, thus impairing organ function. Fibrosis can affect many systems in the body, especially organs such as the lungs, kidneys, the heart and the liver.

סלילים הקולגן מאוגדים יחד בצמות חזקות במיוחד
Collagen fibers twist together to form very strong braids

Do We Need Collagen Supplements?

In recent years the popularity of collagen-containing dietary supplements has been on the rise. Similar to all other proteins in our body, collagen is produced in our tissues according to demand, when these are being built or regenerated, thus we have no need for external augmentation of collagen. Even if we had such a need, the amount of protein in the supplements is very low, if not completely negligible, and would not impact our body’s functioning in the least. On the up side, for the same reason, this supplement cannot harm us—fibrosis develops due to a lack of clearance and breakdown of the collagen, and under normal circumstances the excess collage is broken down to its basic building blocks. 

Collagen is commonly used in cosmetic creams, but its purpose there differs from its purpose in dietary supplements. In cosmetics, collagen serves as a water adsorbent to preserve moisture and enhance the cream’s hydrating properties, rather than being absorbed by the skin. However, collagen is not the only ingredient used for this purpose, and can be substituted with derivatives of vitamins, lactic acid, alcohols and other molecules

הקולגן מיוצר ברקמות בהתאם לצורך, כך שאין לנו כל צורך בתגבור חיצוני שלו
Collagen is produced upon demand in body tissues, thus we have no need for external augmentation of collagen

But the really important point is that the collagen in these supplements simply won’t reach its destination, because it will be broken down long before. Already in the late 1970s it was found that, similar to other proteins, collagen undergoes breakdown in the digestive system into its constituent amino acids, thus consuming it by swallowing is similar to consuming any other protein in our food. Moreover, collagen itself does not contain an exceptional amount of essential amino acids, so even if we are lacking building blocks for protein, far more accessible sources are present in the food we eat.

Furthermore, most collagen supplements do not contain collagen in its whole form at all. As mentioned above, collagen is a very large protein, and due to this it cannot cross the walls of the intestine in which it is supposed to be absorbed (it would be very bad if that could happen). To enable its absorbance, the manufacturers break down the collagen into its basic building blocks—short protein fragments called peptides or even individual amino acids. Although these fragments can be absorbed by the body, they are not collagen, in the same way that glass fragments cannot function as the plate they were once part of. For this reason there is no advantage to consuming amino acids derived from collagen rather than amino acids and peptides derived from any foods that contain protein.  

Nevertheless the supply of these supplements grows constantly, and it’s no wonder—the size of the global beauty supplements market is expected to reach seven billion dollars by 2024, and the manufacturers have a strong incentive to develop new products. In an independent study on 176 dietary supplements, doctors from the United States found that most of these products included outdated nutritional recommendations and presented medical claims that were not supported by independent research studies. In their report, the researchers emphasized that the companies were able to publish such claims due to the relatively moderate control over dietary supplements, in contrast to medical treatments that must meet much tougher requirements.The researchers also noted that although these are only nutritional supplements, they are not free of risks, and must still be tested for potential effects on pregnant women, interdrug reactions and more.

A review performed by the Harvard Medical School sheds some light on the state of collagen supplements and illustrates the importance of independent scientific studies. The review revealed that most of the studies published to date on the activity of collagen supplements were funded by the supplement manufacturers themselves. One of the most important factors in the reliability of scientific research is its independence, meaning that the authors of the study have no interest in obtaining a specific result. 

When a study on a dietary supplement is funded by the company that produces it, particularly when the company is actively involved in this research, there is a concern that the study will be fundamentally biased, since it is obvious that the manufacturers have a strong interest in the success of their products. In reality, the lists of authors of many of the studies included employees of the company itself, and in one study credit was even given to the company’s CEO. Nevertheless, studies performed on collagen supplements failed to prove that there is a difference between collagen consumption and a balanced consumption of proteins as part of a balanced diet

Our body, therefore, is a well-oiled metabolic machine. Thus, it is able to convert the proteins absorbed from food into their building blocks - amino acids - and to produce from them all of the body’s proteins. Collagen is only present in foods of animal origin, but despite this there is no evidence that a vegan diet has any kind of impact on the production of proteins and collagen by the body, as long as it contains the correct proportions of essential amino acids. 

The importance of scientific research for understanding the world is immense. Nevertheless, science itself is also a product of human activity and it is therefore not without biases. Therefore, it is of paramount importance to carry out scientific research in a transparent, honest and independent manner. In a field with such high economic incentives, the palpable absence of independent studies is particularly frustrating and does not bode well for the necessity of these nutritional supplements.