Collagen is the main structural protein throughout your body but it is can be found particularly in the skin, bones and muscles. It is a scaffold protein that gives smoothness and elasticity to skin, but its production declines with age. Hydrolysed collagen-based supplements are proven to repair skin damage, promoting a youthful and healthy appearance.

Hydrolysed collagen is obtained from native collagen, and it consists of small collagen peptides (fragments) with low molecular weight (0.3–8 KDa). It is formed through a process of hydrolysis which involves breaking down the molecular bonds between individual collagen strands using a combination of heat, acids, alkalis, or enzymes. 

In the gut (stomach and small intestines) hydrolysed collagen is further digested (hydrolysed) to amino acids, dipeptides and tripeptides. The resulting peptides can stimulate fibroblasts in the dermis resulting in an increase in the production of collagen.

Studies have also shown that collagen synthesis varies at the different stages of life. With age, the ability to replenish collagen naturally decreases by about 1.5% per year; collagen fibres become thicker and much shorter; the density of collagen and elastin in the dermis declines. Hence the structure and elasticity of the skin deteriorates, causing it to become thinner and more rigid. 

Numerous clinical trials show the efficacy and benefits of collagen peptides on skin properties such as hydration, elasticity and reduction of wrinkles. In this context, hydrolysed collagen supplementation has a dual mechanism: 

1. Free amino acids are used as building blocks for the formation of new collagen and elastin fibres

2. Collagen peptides bind to fibroblasts receptors and stimulate the production of new collagen, elastin and hyaluronic acid. 

Collagen can be provided by our daily diet in foods such as meat, fish, chicken and bone broth. Collagen can only be obtained in the diet from animal sources, since it is found in the skin, hair, bones and joints (plants do not contain collagen!). In the body, collagen must be broken down to amino acids, dipeptides or tripeptides before absorption into the bloodstream and distribution to body tissues. These very small peptides are then re-assembled by specialised cells in the skin, cartilage and other tissues to make many types of collagen. 

Did you know... 

The word collagen is derived from the Greek word kólla, which means glue, as it is the glue that holds the skin together.

Collagen – Type I, Type II and Type III

Nearly a decade ago, collagen-based supplements started to gather momentum in the Beauty sector, with an increase in lab-based studies supported by validation in clinical trials. An unexpected observation was the improvement of musculoskeletal and joint function with benefits such as improved mobility (for the elderly) or improved performance (in athletes). These early results were achieved with Type I collagen. Later attempts to improve on this using Type II collagen (for cartilage) have led to confusion. 

There are approximately 28 collagen proteins of which the classical fibril forming collagens are Type I, II, II, IV and X. The variations among the collagen proteins are determined by the assembly of the polypeptide chains, the length of the chains, breaks in the chains and termination in the helices, among other factors.

Triple helix structure of collagen fibril

The functions of the different collagens depend on the assembly of the polypeptide chains into fibrils and fibres that are incorporated into the tissue matrix.

Type I is the most abundant (80-90% of the collagen in the skin) and studied member of the fibrillar collagens but is actually very similar in synthesis and protein structure to Type II and Type III.

As a protein being processed through the digestive system, there is negligible difference between Type I, II and III collagens and there are negligible differences in using Type I and Type II collagens as a supplement.

The key differences between Type I, II and III collagens are defined by where in the body they are produced and their local tissue environment. 

Similarities between Type I and Type II Collagen:

As proteins and fibres Types I and II are very similar in their composition and structure. The table below shows that the amino acid compositions of collagen types I, II and III are very similar, particularly in their percentages of Glycine, Proline and Lysine residues.

Hydrolysed Collagen (typically provided as Type I or Type II) must be broken down to amino acids, dipeptides or tripeptides before absorption into the bloodstream and distribution to body tissues. In the skin fibroblasts will synthesise new type I collagen and in the joints chondrocytes will synthesise new type II collagen. Both proteins require almost identical proportions of amino acids and so it makes almost no difference which collagen type is supplied in the supplement.

Thus, any supplements using Type I or Type II collagens will have similar benefits in skin or joints.

Differences:

• In skin, Type I collagen forms thick fibres that are packed in an ordered structure side-by-side (left)

• In cartilage, Type II collagen forms fine fibres that are randomly positioned in a proteoglycan matrix (right)
  

The arrangement of collagen fibrils in the skin and cartilage cannot be influenced by supplements or the form of hydrolysed collagen used and is totally dependent on the activity of the fibroblast or chondrocyte.