Collagen — research review 2

...and this is where the human evidence really matters. We see a lot of hype about molecules, but what do clinical trials actually show? Take collagen, for example. It's the main structural protein in our skin and bones.

Right. The theory is that oral collagen peptides could replenish what we lose with age, improving skin, bones, and joints. And some human trials do support this. A study in Nutrients in 2019, for instance, found that a test product significantly improved skin hydration, elasticity, roughness, and density compared to a placebo.

And another Nutrients study from 2018 reported that after twelve weeks, the collagen group showed significantly improved visual wrinkle scores and other wrinkling parameters against placebo. So, some clear skin benefits there.

It's not just skin, either. Bone mineral density also saw improvements. That same year, another Nutrients study showed BMD of the spine and femoral neck increased significantly versus a control, and a marker for bone formation, P1NP, also rose. And for joints, Nutricion Hospitalaria in 2015 noted hydrolyzed collagen stimulates collagenic tissue regeneration.

But it's important to remember that collagen doesn't work in isolation. We know vitamin C is an essential cofactor for collagen synthesis, and retinoids signal skin cells to produce more collagen. Vitamin K2 activates proteins crucial for bone structure.

Exactly. The human evidence is there for some benefits, like skin elasticity and bone density, but many questions remain about long-term effects, optimal dosages, and how it interacts with other nutritional factors. We can also get collagen building blocks from natural sources like gelatin with vitamin C before exercise, which American Journal of Clinical Nutrition showed doubled new collagen synthesis markers. Or simply vitamin C foods themselves.