There are a lots of names for collagen peptide and it is also called hydrolyzed gelatin, gelatin hydrolysate, hydrolyzed collagen, collagen protein, etc. Gelatin is often broken down again into smaller, flavorless and colorless peptides that are added to foods as a nutritional supplement, so as not to alter the food flavors.
Because of its tryptophan deficiency, an essential amino acid for human, gelatin and its hydrolyzed product were considered incomplete protein without good nutritional value for a long time. In recently, people know that gelatin and protein from other food can complement each other to improve their biological value. For example, when 16% gelatin and 84% beef are mixed, their biological value is 98. It is very close to the biological value of egg which is 100. The synthesis of non-essential amino acids from essential amino acids is not efficient, so the non-essential amino acids in hydrolyzed gelatin are also important for health. This's why many dietary supplements include collagen peptide to complement the protein in food.
According to the traditional theory, protein should be hydrolyzed into polypeptides, then into small peptides. They can only be absorbed by intestine when they completely become amino acids. Therefore, many people believe that it is unreasonable to eat collagen to nourish skin and bones and its nutritional value is not as good as meat. However, recent studies have shown these small peptides can be directly absorbed by small intestine and mucosa of mouth and stomach, and they also have biological activity.
Ingestion of collagen peptide makes your skin younger. When the biologically active peptides are absorbed, they accumulate in dermis and bind to receptors of fibroblasts. These stimulated cells synthesize more collagen, producing thicker and denser collagen fibers and more hyaluronic acid. Some of small peptides in hydrolyzed collagen also have antioxidant property, which can destroy free radicals and slow down the skin aging. Long-term oral consumption of gelatin hydrolysate results in thicker dermis, increased skin water content, more elastic skin and fewer wrinkles.
Some dietary foods are added collagen peptide to relieve osteoporosis and joint diseases. Similar to skin rejuvenation, the peptides accumulate near bone and cartilage to activate the osteoblasts, causing it to secrete more collagen that is component of bone and hydroxyapatite is deposited in it. The long-term oral intake of edible gelatin or hydrolyzed gelatin can repair the damaged cartilage, relieving joint pain and improving joint flexibility. It can also prevent calcium loss and increase bone density; more collagen in the bone can make it more resilient and less likely to fracture.