Approximately one third of the proteins found in our body is collagen. Collagen comes from the Greek word for glue and is a major player holding us together. Collagen is found in bone, muscles, tendons, ligaments, blood vessels, eyes and teeth. It has gained increased popularity as a supplement and can be found as an additive in various skin and hair products.
How and why do we make collagen? The answer requires a bit of evolutionary history.
To make collagen, you need lots of vitamin C and energy.
Vitamin C has been made by plants and certain animals for many millions of years.
For animals, energy comes from the mitochondria found inside the cell. However the byproduct of making energy is reactive oxygen species (ROS) . ROS is highly destructive. Single cell animals have it easy. Just toss ROS overboard out of the cell into the surrounding water. Need nutrients for energy? Absorb what you need through your cell wall and live on.
What about multicellular animals?
To move nutrients in and get waste products out of cells, you need a circulatory system and some “blood.” And to prevent blood leaking out, you need blood vessels, and to make blood vessels you need collagen.
If you want to evolve, you call on your mitochondria to make more energy which in turn produces more ROS.
And there is the rub. Vitamin C is an antioxidant and gets depleted by the increased ROS levels.
No vitamin C, no collagen.
The first life forms known to to make collagen are sponges, whose ancestors evolved about 600M years ago.
The lowly sponge is a pretty talented biochemist. To pull off collagen production, it first accumulated astaxanthin from carotenoids in its algae diet. Astaxanthin is 1000X more powerful than vitamin C as an antioxidant. Once astaxanthin was in place, the cell diverted its Vitamin C into collagen production, eventually evolving blood vessels to link up with other cells and filling the vessels “blood” to get nutrients exchanged and to dispose of waste products.
This chemistry was quickly duplicated by other animals leading to the Cambrian explosion. All kinds of multicellular lifeforms evolved the capacity to make astaxanthin and vitamin C, hence collagen and voila, shells, bones and everything else begins to appear in the fossil record.
By the time humans evolved, we didn't need to bother spending energy to synthesize astaxanthin or vitamin C. All we had to do was eat other lifeforms that had these critical compounds for collagen production.
That strategy worked well until we industrialized food in the 1960s, reducing vitamin C and virtually eliminating astaxanthin from many modern diets. What followed is a loss collagen production and the rise of chronic and immune disorders that are so prevalent today.
Perhaps sponges are smarter biochemists than humans. But we are at least smart enough to take vitamin C and astaxanthin supplements every day so that we can continue to make enough collagen to hold ourselves together.