three amino acids you will only really find in collagen

For a while I assumed collagen was just protein with better branding. Protein is protein, I thought, my body pulls it apart either way, so why would the source matter.

The amino acid profile is the reason that is wrong, and it is more interesting than I expected.

the profile is genuinely unusual

Every protein is a specific sequence of amino acids, and collagen has a sequence unlike almost anything else you eat. Three dominate it: glycine, proline, and hydroxyproline. Between them they account for around half the entire molecule, which is not how most proteins are built.

Chicken breast will not give you that ratio. Neither will eggs, or whey, or a lentil. You get it from collagen, or from the slow simmered bones and skin that most of us stopped cooking two generations ago. When people say the modern diet is missing something, this is a concrete example rather than a vague one.

glycine, the small one

Glycine is the smallest amino acid that exists, and roughly every third link in the collagen chain is one. That is structural. The triple helix winds so tightly that only something as small as glycine fits in the middle.

Outside collagen, glycine is busy. Your body uses it to make glutathione, one of its main antioxidants. It goes into bile salts and into creatine. It acts in the nervous system, where it has the sleep research I have written about separately.

Most people take in around two to three grams a day from ordinary food. A 2009 analysis in the Journal of Biosciences argued that this falls short of what the body could actually use for collagen synthesis, and called glycine a weak link in human metabolism. A single can of LÉS carries several grams of it.

proline, the one that bends

Proline has an unusual ring shape that puts a deliberate kink in a protein chain. In most proteins a kink is a problem. In collagen it is the entire point. Those kinks are what allow three separate strands to twist around one another into a rope, and a rope is exactly what a tendon needs to be.

hydroxyproline, the fingerprint

This is my favourite, because it barely exists anywhere else in nature. Hydroxyproline is proline with an oxygen and hydrogen attached, and your body creates it after the chain is already assembled, using an enzyme that runs on vitamin C. That is the real link between vitamin C and collagen, and it has its own piece here because it deserves the room.

Hydroxyproline is so specific to collagen that scientists use it as a measuring stick. If you want to know how much collagen is in a tissue sample, you measure the hydroxyproline, because there is nowhere else it could have come from.

It matters for a second reason too. When you drink hydrolysed collagen, it is not all broken down into loose amino acids. In 2005, Iwai and colleagues measured human blood after people drank gelatin hydrolysate and found short collagen peptides still intact, particularly a pair called proline-hydroxyproline. Later work by Shigemura and colleagues showed that same peptide stimulating the growth of skin fibroblasts, the cells that produce new collagen.

That is a satisfying loop. You drink collagen, specific fragments of it survive digestion and enter your bloodstream, and those fragments appear to act as a signal to the cells that build collagen.

why this shaped our can

Collagen is not competing with your eggs or your protein shake. It is a different material doing a different job, supplying the specific building blocks your body cannot easily get anywhere else.

Twenty grams of collagen protein per can, from 22 grams of grass fed peptides, is a real delivery of glycine, proline and hydroxyproline in one cold drink. That is the whole idea.

the research i leaned on

• Iwai K, Hasegawa T, Taguchi Y, et al. Identification of food-derived collagen peptides in human blood after oral ingestion of gelatin hydrolysates. Journal of Agricultural and Food Chemistry. 2005;53(16):6531-6536.
• Shigemura Y, Iwai K, Morimatsu F, et al. Effect of prolyl-hydroxyproline (Pro-Hyp), a food-derived collagen peptide in human blood, on growth of fibroblasts from mouse skin. Journal of Agricultural and Food Chemistry. 2009;57(2):444-449.
• Meléndez-Hevia E, De Paz-Lugo P, Cornish-Bowden A, Cárdenas ML. A weak link in metabolism: the metabolic capacity for glycine biosynthesis does not satisfy the need for collagen synthesis. Journal of Biosciences. 2009;34(6):853-872.

LÉS is a beverage, not medicine, and nothing here is medical advice.