What is collagen

Collagen is a protein. In fact, it is the main structural protein (in the extracellular matrix) found in connective tissues in the human body. These connective tissues being the skin, bones, cartilage, ligaments and tendons. Although, I suspect your reason for reading this is connected to its presence in the skin.

There are several types of collagen in the human body, though, approximately 90% is type I collagen. Type I collagen is a fibrillar type collagen, which is also the main type of collagen found in the skin. This post will therefore focus on type I collagen and its connection to the skin, in relation to collagen supplements.

The skin has three layers:

1. Epidermis (top layer) – this is the outermost layer of skin which serves as the body’s first line of defense against the environment. The environment being UV light, pathogens, toxins etc.
2. Dermis (middle layer) – this middle layer of skin houses connective tissue, blood vessels, oil and sweat glands, nerves and hair follicles (amongst other structures). Cells called fibroblasts – found predominantly in the connective tissue of the dermis – produce the proteins collagen and elastin, which are responsible for the structural integrity of our skin. As we age we see a loss in collagen and elastin, resulting in fine lines and wrinkles.
3. Hypodermis (bottom layer) – this bottom layer is made primarily of subcutaneous fat. This storage of fat acts as an energy reserve, provides insulation and protects internal organs and other structures from mechanical injuries. Other components of the hypodermis include connective tissue, blood vessels and nerve cells. The blood vessels here are larger and connect to the rest of the body. 

Age-related changes in the skin

Ageing of the skin is a complex, multifactorial process in which the interplay between your genetics, lifestyle, exposure to environmental factors (eg sun exposure), as well as your emotional and medical state play a role. As we age a reduction in cell division, blood circulation, muscle strength and metabolic activity occurs. A reduction in these biological processes all lead to visible signs of ageing in our skin:

• As we age we see a reduction of mitosis in the stratum basale which leads to a thinner epidermis. We also begin to lose hyaluronic acid i.e the water-loving molecule that keeps our skin looking plump and hydrated.
• We also see a breakdown of connective tissue in the dermis and hypodermis, this combined with reduced fibroblast activity leads to wrinkling of the skin due to loss of collagen and elastin.
• The reduction and redistribution of fat in the hypodermis contributes to sagging of the skin

The structure of collagen

We know that collagen is a protein, but what does that actually mean? Amino acids are the building blocks of proteins. Thus, you guessed it….amino acids form the foundation of collagen. A repeated sequence of three amino acids (this sequence being glycine-proline-X or glycine-X-hydroxyproline, where X=other amino acid) makes up a singular polypeptide chain. This polypeptide chain then organises itself into a secondary α-helix structure.

Three of these polypeptide chains (α-helix’s) then form a right-handed triple helix. All types of collagen contain a long stretch of triple helix connected to different types of ends. Type I contains many long triple helices with blunt ends which associate to form fibrils. Many of these fibrils then form a fiber.

P.S. Hydroxyproline is generated by modification of proline after the collagen chain has formed. Vitamin C is vital for this process.

Why does any of this matter? Well, many anti-ageing strategies target collagen production (and other important structures) using collagen supplements.

What are collagen supplements

Collagen supplements come from several sources – bovine, porcine, marine (P.S. collagen is collagen, no matter its source). Different formulations such as protein, gelatine, hydrolysate and peptide forms are usually available. The reduction of fine lines and wrinkles are often a selling point of these supplements.

The supplement industry is by far and large, unregulated, so no two supplements are the same, or behave in the same way. There are several ways these supplements aim to aid collagen production/retention (see the next section).

Is taking collagen supplements effective?

As I have just alluded to, there are several ways collagen supplements aim to help reduce fine lines and wrinkles. See below:

Collagen protein (raw/undenatured)

Once consumed, collagen protein gets digested into smaller peptides and there has been much debate as to whether these supplements are effective. Generally, clinical evidence that these supplements work is fairly weak. However, when collagen is broken down, hydroxyproline fragments are formed, and whilst it is unlikely that these fragments will regenerate collagen, studies have shown these fragments encourage skin cells to grow faster and produce hyaluronic acid.

Hydrolysed collagen

This is essentially the collagen protein broken down into its fragments, otherwise known as collagen hydrolysate or collagen peptides. In addition, gelatine formulations contain collagen which is only partially broken down into its constituents. Essentially, all forms of collagen will break down when ingested, thus, it becomes a question of how effective the broken down fragments are in aiding collagen production. Some research suggests these hydrolysed forms make it easier for the body to absorb and are thus a better option. Further to this, a study by Edgar et al. showed that hydrolysed collagen peptides increased collagen and elastin synthesis (by fibroblasts) whilst also inhibiting two collagenases which break down native collagen.

Collagen capsules

Lots of collagen supplements come in the form of a powder (eg hydrolysed forms). But brands such as Ingenious Beauty come in capsule form. Their patented plant-cellulose capsules are supposedly better able to resist breakdown of the collagen and thus make it to the small intestine where the body can absorb it better. As you can see, this goes against some expert’s/dermatologist’s preference for hydrolysed forms.

Other methods

Other methods look at activating fibroblasts via the use of ligands that can bind to receptors on the fibroblast extracellular membrane. These ligands can be antioxidants, retinoids, growth factors, certain vitamins and more. I’d say the jury is still out on how effective different supplements are (if at all).

Key takeaways

• Word is still out on whether collagen supplements are effective and also, which form is best
• Some sure-fire ways to keep younger looking skin would be to use sun protection and retinoids (click here to learn about the different types of retinoid and how they work)

References

Bolke, L.; Schlippe, G.; Gerß, J.; Voss, W. A Collagen Supplement Improves Skin Hydration, Elasticity, Roughness, and Density: Results of a Randomized, Placebo-Controlled, Blind Study. Nutrients 2019, 11, 2494. https://doi.org/10.3390/nu11102494

Reilly DM, Lozano J. Skin collagen through the lifestages: importance for skin health and beauty. Plast Aesthet Res 2021, 8, 2. http://dx.doi.org/10.20517/2347-9264.2020.153

Choi FD, Sung CT, Juhasz ML, Mesinkovsk NA. Oral Collagen Supplementation: A Systematic Review of Dermatological Applications. J Drugs Dermatol. 2019 Jan 1;18(1):9-16.

Ohara H, Ichikawa S, Matsumoto H, Akiyama M, Fujimoto N, Kobayashi T, Tajima S. Collagen-derived dipeptide, proline-hydroxyproline, stimulates cell proliferation and hyaluronic acid synthesis in cultured human dermal fibroblasts. J Dermatol. 2010 Apr;37(4):330-8. doi: 10.1111/j.1346-8138.2010.00827.x.

Edgar S, Hopley B, Genovese L, Sibilla S, Laight D, Shute J. Effects of collagen-derived bioactive peptides and natural antioxidant compounds on proliferation and matrix protein synthesis by cultured normal human dermal fibroblasts. Sci Rep 2018;8:10474.