All about collagen: types, benefits, sport and health
Collagen is much more than just a buzzword in the world of beauty and wellness.
It is an essential protein that provides structure, strength, and flexibility to our tissues: skin, joints, tendons, bones, hair… nothing escapes its influence.
But what do we really know about collagen? What are its different types? Why does its production decrease with age? And how can diet or supplements help stimulate it?
Here's everything you need to know about collagen, according to the latest scientific research.
What is collagen?
Collagen is a fibrous protein that accounts for approximately 30% of the total protein in the human body.
It acts as a "biological glue" (from the Greek kólla, glue), ensuring the cohesion and elasticity of connective tissues.
Collagen structure
It is primarily formed from three amino acids: glycine, proline, and hydroxyproline, which intertwine into a triple helix to form a very strong structure.
The main types of collagen
There are at least 28 types of collagen in the human body.
The most important are:
| Type | Primary Location | Function |
| Type I | Skin, tendons, bones, ligaments | Firmness, elasticity, wound healing |
| Type II | Cartilage, intervertebral discs | Mobility, joint health |
| Type III | Skin, muscles, blood vessels | Tissue flexibility |
| Type IV | Basement membranes | Cellular support |
| Type V | Hair, placenta, cornea | Fine tissue structure |
In cosmetics and nutrition, types I, II, and III are the most studied and used.
Collagen production decreases with age
From the age of 25, the natural synthesis of collagen begins to slow down by approximately 1% per year.
This decrease is exacerbated by:
- Oxidative stress (pollution, tobacco, UV, poor diet)
- Lack of vitamin C
- Hormonal deficiency (menopause)
- Insufficient sleep and chronic stress
- Visible consequences:
- Wrinkles and loss of skin firmness
- Stiffer joints
- Decreased bone density
- Brittle nails, dull hair
According to a study published in Dermato-Endocrinology (2012), the reduction of dermal collagen is one of the main markers of skin aging.
The best dietary sources of collagen (and precursors)
Direct sources (animal)
- Bone broths (chicken, beef)
- Fish skin (marine collagen)
- Cartilage and gelatin
Plant sources (precursors)
Plants do not contain collagen, but provide the amino acids necessary for its synthesis:
- Glycine: almonds, lentils, soy, pumpkin seeds
- Proline: oats, beans, soy, millet
- Lysine: lentils, edamame, chickpeas
- Vitamin C (essential cofactor): kiwi, red bell pepper, citrus fruits, broccoli, guava
Source: USDA FoodData Central, ANSES, NIH – Office of Dietary Supplements
Collagen vs. collagen peptides: what's the difference?
Hydrolyzed collagen or collagen peptides are forms broken down into small amino acid fragments.
These peptides are more easily absorbed by the intestine and can reach the skin, cartilage, or connective tissues.
According to several clinical studies (e.g., Journal of Cosmetic Dermatology, 2021), collagen peptide supplementation significantly improves skin hydration and elasticity after 8 to 12 weeks.
In summary:
| Form | Structure | Assimilation | Usage |
| Native collagen | Complete protein | Low | Joints (type II) |
| Collagen peptides | Hydrolysate (small peptides) | High | Beauty, sport, regeneration |
Collagen, sport, and health
Collagen plays a crucial role in:
- Strengthening tendons and ligaments
- Improving muscle recovery
- Preventing joint injuries
A study from Nutrients (2019) showed that daily supplementation of 10g of collagen peptides combined with vitamin C increased collagen density in tendon tissues in athletes.
Furthermore, collagen contributes to bone health by supporting the organic matrix that binds calcium.
How to naturally stimulate collagen production?
- Eat a protein-rich diet (legumes, soy, quinoa, eggs, fish or meat depending on diet).
- Ensure vitamin C intake with every meal.
- Consume antioxidants (berries, green tea, turmeric).
- Avoid tobacco and excessive sugar, which accelerate collagen degradation.
- Stay hydrated and get enough sleep to promote cell regeneration.
Recent scientific studies on collagen
- Shigemura et al., Journal of Agricultural and Food Chemistry, 2009 – Collagen peptides are absorbed as specific di- and tri-peptides (Pro-Hyp) and stimulate skin collagen formation.
- Zague et al., Nutrients, 2018 – Hydrolyzed collagen supplements improve skin elasticity, hydration, and dermal density.
- Kouvelioti et al., Amino Acids, 2020 – Collagen intake improves tendon recovery and reduces joint pain in athletes.
In summary
Collagen is a pillar of health and beauty.
With age, its decline is inevitable, but a diet rich in amino acids, vitamin C, and antioxidants, combined with a healthy lifestyle and possibly supplementation, can help preserve your skin, joints, and vitality.
By nourishing your collagen, you are literally nourishing your inner youth.
