This article was originally written on April 21, 2020 and updated on October 13, 2021.
The popularity of collagen supplements has exploded in recent years. Collagen is also being introduced to a variety of processed foods such as protein bars, teas and creamers. There are also foods that are naturally rich in collagen, the most popular of which is bone broth. Collagen is credited with a large range of benefits, such as reducing joint pain, reducing wrinkles, promoting weight loss and optimizing athletic performance. Is this purely due to marketing, or are these effects really based on scientific evidence? I invite you to read on to find out more!
Collagen is a protein found in various body structures such as skin, cartilage, tendons, ligaments, bone tissue, muscles and connective tissues. It ensures the cohesion, elasticity and regeneration of all these tissues. For example, collagen is largely responsible for the elasticity and strength of the skin, and its degradation leads to aging of the skin and wrinkles. Collagen contains 19 different amino acids (basic protein structures) with a particularly high content of hydroxyproline, glycine and proline. However, collagen is not a complete protein because it does not contain tryptophan, one of the nine essential amino acids.
Collagen is naturally present in many foods. Bone broth is made by simmering bones in a broth for 24 hours or more in order to break down the bones and release their nutrients and minerals. In humans and animals, collagen is concentrated in connective tissues such as muscles. Thus, all meats (beef, pork, poultry, etc.) that contain muscles or other connective tissues (as opposed to organ meats) are rich in collagen. Other good sources of collagen include fish and egg whites. Spirulina (which comes from algae) is not a source of collagen, but it does contains nutrients that can promote the body’s production of collagen. In addition to amino acids, several other nutrients are important for collagen production in the body. Vitamin C is a necessary cofactor for collagen synthesis and also functions as an antioxidant to combat oxidative stress. Vitamin C is found in a variety of fruits and vegetables including citrus fruits, peppers, strawberries and kiwis. Zinc and sulphur are also important cofactors in collagen production. Sulphur is commonly found in broccoli, onions and garlic, and zinc is found in a variety of foods such as shiitake mushrooms, beans, tofu, nuts, seeds and whole grains.
Collagen in supplement form is derived from gelatin. Gelatin is made by subjecting the bones and skin of animals, most often cattle or farmed pigs, to different treatments. Collagen supplements can also be made from by-products of fish processing, such as scales, skin and bones. To facilitate their absorption, collagen supplements are hydrolyzed into peptides consisting of only two or three amino acids together.
Although it is possible to consume collagen directly via food or supplements, it is not necessary to do so to support collagen production in the body. Indeed, the body does not absorb collagen molecules in their whole form, but rather breaks them down into their composite amino acids, which it then uses to synthesize its own collagen and other proteins. In theory, the amino acids needed to produce collagen in the body can come from any source of protein, such as bone broth, meat, cheese, beans or quinoa. Similarly, when consuming a supplement or a food containing collagen, it is impossible to determine in advance where collagen peptides will be used in the body and whether they will actually be used to produce collagen in the body. Consumers often take collagen to obtain a specific benefit, such as to improve their skin elasticity or joint function, however, if the body needs amino acids at that time for another function, this will be the body’s priority.
Almost all of the existing studies looking at the benefits of collagen used collagen supplements in their research, not collagen-containing foods.