Collagen Types I, II, III: What for Joints and What for Skin? Myths and Reality

Collagen is one of the most important proteins in our body, forming the basis of connective tissues and ensuring their strength, elasticity and hydration. Collagen is not only made up of bones and tendons, but also skin and other organs. In recent years, it has become a very popular ingredient in dietary supplements and cosmetic products. In this article, we will focus on the differences between the individual types of collagen (primarily types I, II and III), explain the difference between native and hydrolyzed collagen and also look at which collagen is suitable for joint care and which for skin.

Types of collagen and their importance

Over 20 types of collagen have been discovered in the human body, but the most important and most frequently mentioned in connection with health and beauty care include:

1. Type I collagen
• It is the most widespread (80–90% of total collagen in the body).
• It is found in the skin , bones, tendons, ligaments and teeth.
• It ensures the strength and elasticity of these tissues.
2. Type II collagen
• It is predominantly found in articular cartilage and the vitreous of the eye.
• It contributes to the elasticity and resistance of cartilage.
• Sought after especially in dietary supplements aimed at supporting joints.
3. Type III collagen
• It occurs in the walls of blood vessels, in the uterus, or in organs with a high proportion of reticular fibers (e.g. liver, spleen).
• It often appears in association with type I collagen.

Each of these types has a slightly different role in the body. However, in practice, you will most often encounter products containing type I collagen , or a combination of types I and III. Type II collagen is then available in specialized products intended for joint nutrition.

Native vs. hydrolyzed collagen

Native collagen is a protein in its original, three-dimensional helical structure (triple helix). It is solid, insoluble, and found in tissues in an almost intact form. However, it is not often found in dietary supplements and cosmetic products because it generally has large molecules that are poorly absorbed and is difficult to dissolve.

Hydrolyzed collagen (also known as collagen peptides) is produced by controlled hydrolysis, usually enzymatic , which breaks down long protein chains into shorter peptides:

• These peptides have a lower molecular weight and dissolve easily .
• They are better absorbed and the body uses them effectively to create new collagen fibers.
• They retain a high content of amino acids typical of collagen (glycine, proline, hydroxyproline), which are key for building connective tissues.

The question is often raised as to whether the “type” of collagen is retained after hydrolysis. Essentially, the original structural features of types I, II, III, etc. are lost because the enzymatic cleavage disrupts the entire helix. The differences between the original types of collagen are therefore partially erased . However, each product may combine peptides and amino acids in a slightly different way, depending on the starting material (e.g. fish skin, beef skin, chicken cartilage).

The suitability of individual types of collagen and myths surrounding their use

1. For skin health
• Type I collagen is most abundant in the skin. Therefore, products with hydrolyzed type I collagen (for example, from fish skin or beef hide) are associated with improving the elasticity, hydration, and appearance of skin, hair, and nails.
• Type III collagen can play a complementary role in supporting tissue and vascular health, but we most often see it in combination with type I.
2. For joint health
• Type II collagen is a component of articular cartilage. Therefore, it is often stated that collagen peptides prepared from type II collagen are ideal for supporting the musculoskeletal system – e.g. in dietary supplements for athletes or people suffering from joint problems.
• Although type I collagen is most associated with the skin, there is increasing evidence that hydrolyzed peptides derived from type I collagen are also beneficial for the joint system.

Studies supporting the effect of fish collagen (type I) on joints

Although there is a widespread belief that fish collagen (type I) is mainly intended for beauty, there are clinical studies that speak of a wider range of its uses:

• Naticol® Joint Health 2020 Clinical Study
• It was conducted as a double-blind, randomized, placebo-controlled study on 30 subjects (average age 61 years).
• A daily dose of 10 g of collagen peptides from fish collagen type I (Naticol®) led to a significant reduction in joint problems after 8 and 12 weeks, as assessed by the internationally recognized WOMAC index (Western Ontario and McMaster Universities Arthritis Index).
• Both pain scores and physical function (mobility and ability to perform normal daily activities) improved.
• This study therefore shows that type I collagen from fish skin can also have a positive effect on joint health - its hydrolyzed form offers high absorbability and the body can use it effectively.

The reason for this is mainly the versatility of the amino acids in collagen peptides. The body breaks them down and reuses them where they are needed, whether it's the skin or the joints.

Myths and reality about collagen in practice

1. Myth : “Fish (type I) collagen is just for beauty, not for joints.”
• Reality : Studies (e.g. Naticol® Joint Health 2020) suggest that hydrolyzed fish collagen type I may also have a positive effect on the joint system.
2. Myth : “Only type II collagen is good for joints.”
• Reality : Although type II collagen is directly present in cartilage, type I collagen peptides also participate in the overall regeneration of connective tissues.
3. Myth : “The type of collagen before hydrolysis determines its exact effect.”
• Reality : During hydrolysis, the original structures are disrupted. Although the initial type of collagen has a certain influence on the resulting combination of peptides, the correctly chosen hydrolysis method and the quality of the product play a crucial role .

Collagen is a universal building block protein and the body can use it in many ways. Type I collagen is not only essential for youthful and healthy skin, but thanks to a new generation of clinical studies, it is also shown to help support joints. So if you are looking for comprehensive benefits for both your skin and musculoskeletal system, hydrolyzed collagen peptides (e.g. from fish skin) are an interesting and proven choice .

• Naticol® Joint Health 2020 (Weishardt) – A clinical study with 30 subjects, double-blind, randomized, placebo-controlled, demonstrating the positive effect of hydrolyzed fish collagen type I on reducing pain and improving physical joint function.