Collagens contain the unique amino acid hydroxyproline (approx. 12%) and an unusually high content of glycine and proline (approx. 22% and 13%, respectively), which are explained by the structure and function of collagen fibrils/sheets. Approximately 25-30% of human body proteins are represented by collagen type proteins, which are essential in human anatomy and physiology.
They are signaling molecules and significant structural components, making up 75% of skin, 64% of corneal tissue, 50% of cartilage, 65-80% of tendons, 70% of ligaments, 10- 11% of muscle, 16% of bone, 10% of lung, 12-24% of aorta, and 30% of tooth dentin. The amino acid and peptide compositions of dietary collagens are very similar to those in human collagens and may be derived from various sources such as pork, beef, fish or chicken. Consequently, dietary collagen peptides provide nutritional support for optimization of body collagen turnover and renewal.
Why We Need Dietary Collagen Peptides
With aging and overuse, connective tissues (skin, cartilage, tendons, ligaments, bones) lose volume and functionality, a phenomenon aggravated by the natural decline in sex/growth hormones, poor nutrition and inadequate physical activity. Supplementation with collagen peptides has shown potential to slow or even reverse some of the degenerative processes occurring in connective tissues.
Average diets do not incorporate enough collagen protein per day because most people avoid eating the skins on meats, and tendons that popular in Asia but don't form a part of the North American diet. Historically, collagen protein was part of natural diets, such as the Paleolithic type. However, owing to our longer lifespans and the toll aging takes on collagen synthesis and maintenance, modern humans may need collagen protein more than did our hominid ancestors.
In the last half of the modern lifespan (after age 40), there is a higher need for nutritional support from collagen protein, especially in the peptide form. Based on the total requirement for EAA intake per day and average intake of EAAs in US, it was estimated that up to 32% of total protein intake may be incorporated in the form of collagen proteins without causing any deficiency in total EAA intake.
This dietary strategy maximizes support for body collagen turnover and renewal. When collagen turnover and renewal slow down, so does the rate of replacing modified, dysfunctional collagen and elastin in tissues. These modifications accumulate with aging, are typically caused by glycation and racemization, and, for example, may manifest as joint stiffness or loss of tissue elasticity.