Importance of Collagen for our Body

Collagen is big structural proteins that help the body to maintain its strength and flexibility, it is found mostly in the skin, bones and connective tissue, and makes up approximately 1/3 of the protein in the body. This makes collagen the biggest source of protein in humans (1). 

Connective tissue is found everywhere in the body and is important for providing structural support, strengthen, stiffen and simply keep the body together. We find connective tissue in tendons, cartilage and ligaments amongst other places. The cells of connective tissue are scattered and between them are plenty of protein collagen fibres with high tensile strength.

We distinguish between loose and firm connective tissue, where the loose tissue contains few fibres between the cells, while the firm tissue is almost entirely composed of collagen fibres. The loose tissue can be found underneath the skin and mucous membranes, around the glands, between muscle fibres and nerves as well as in and between organs and other tissues. Loose tissue has great tensile strength and elasticity in all directions. Firm connective tissue is found in tendons and ligaments that attach muscle to bone and bone to bone. Firm tissue has, in tendons, a very high tensile strength in the direction of the fibres, while in ligaments have high tensile strength in all directions. Collagen fibres helps to form the foundation for skin, hair and nails (2).

Vitamin C is important in the synthesis of collagen, in which it interacts with the amino acids proline and hydroxyproline. Vitamin C provides hydrogen and oxygen so that the amino acids can do their part in the production of collagen. If you lack vitamin C the collagen production will decline. Today there are several approved claims for vitamin C in relation to the formation of collagen for normal function of bones, cartilage, skin and blood vessels (EFSA, vitamin C claims).

COLLAGEN TYPE I

The two most common types of collagen is Type I and Type II. Type I is found throughout the entire body, except in the cartilage tissue, and accounts for most of the collagen in our body. Type II is the most important part in cartilage and synovial fluid. Type I, II and III constitute 80-90 % of the collagen in our body, where type I comprise most of it. 

The collagen obtained from fish is of type I and is produced and organized in cells in skin and connective tissue as well as playing an important role in bone tissue. It is not only in relation to the elasticity and structure of the bone, but also in relation to key processes in bone mineralisation and metabolism (1). Marine collagen is absorbed up to 1,5 times more efficiently in the body, and the bioavailability is superior to collagen of both bovine or porcine. This is due to its smaller particle size compared to other types of collagen. The smaller particle size allows an easier and faster uptake and transportation of the collagen peptides to the skin, bones and joints for the synthesis of new collagen.

Before protein can be absorbed and transported around the body, it has to be broken down in the stomach into short peptides and amino acids. It appears that the body can easily absorb short peptides and thus utilize them quickly in the body. Some of these peptides have bioactive properties, which means that they can exert positive effects in the body beyond being a nutrient. The focus on biologically active peptides from different protein sources has increased among researchers. Through cell cultures and animal studies researchers have already identified several sequences that look promising. Different areas that has been studied is especially effects on blood pressure regulation, immune system, cancer, pain response and cholesterol (3).

Sources: 

1. Marcus, R., Feldman, D., Kelsey, J. (eds) (1996) Osteoporosis. Academic, New York

2. Sibilla, S., Godfrey, M., Brewer, S., Budh-Raja, A., Genovese, L. (2015). An overview of the beneficial effects of hydrolysed collagen as a neutraceutical on skin properties: scientific background and clinical studies. The Open Nutraceutical Journal 8, 29-42.

3. BT innsikt, Profesjonelle proteiner: http://innsikt.bt.no/profesjonelle-proteiner/ Schrieber, R., Gareis, H. (2007) Gelatine Handbook: Theory and Industrial Practice. Wiley-VCH, Weinheim, 347 pp.