Collagen: Science or pseudo?

Too often, the beauty industry uses pseudoscience to promote its products. Even as a trained scientist, it's difficult to tell the difference between fact, embellishment, and downright fiction.

Further complicating matters, cosmetics do not need FDA approval. Cosmetic regulation by the FDA is minimal, and the laws governing its practice have not changed since 1938. The FDA's power over the cosmetic industry is limited to removing products from the market if they are "adulterated" or "misbranded." In other words, a product can be nixed if it contains a poisonous or spoiled ingredient or if the label provides misleading information.

With the lack of cosmetic regulations, consumers have to ask, "Does this product even work?" Can you trust that charcoal will cleanse your blackheads, that hyaluronic acid will plump your under-eyes, or that collagen will increase the elasticity of your skin?

Today's article will be the beginning of a series of posts on the science of common cosmetic additives. To begin with, we will explore the biology and chemistry of one of skin care's most prevalent ingredients, collagen.

What is Collagen? 

Collagen is a natural biomolecule produced by animals, acting as structural support for cells within our connective tissues such as skin, bone, tendons, and cartilage. There are 28 subtypes of collagen, all with similar function.

Collagen is a protein, meaning it's made up of a chain of amino acids folded into a unique shape. Specifically, collagen is made of 3 amino acid chains, twisted together to form a long, helical stretchy protein:

Crystal structure of a collagen peptide

Like all proteins, the structure of collagen is integral to its function. The long helical fibers of collagen act like a spring. They can stretch and twist during movement, providing support and elasticity to tissues.
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The collagen in most skin products is sourced from animals, usually, cows, pigs, or fish, although growing collagen using yeast or bacteria is possible in a laboratory. Full-length collagen is fibrous and non-soluble, so most collagen in our moisturizers, serums, and sunscreens are hydrolyzed, consisting of shorter segments of the protein.

Collagen in skincare

Many biological mechanisms contribute to skin aging, including a decreased production and a deterioration of collagen networks. Intuitively, collagen supplements may alleviate wrinkles and loss of elasticity. But is there scientific evidence to support that collagen is an effective anti-aging additive? Or is an untested theory the driving force of collagen sales?

Quite a few studies support that hydrolyzed collagen has anti-aging effects when used topically. For example, in a 2019 study, participants given topical collagen had increased skin hydration and elasticity in just 28 days, while wrinkles improved after 90 days of treatment. A more recent study also reports topical collagen as an effective cosmetic. Participants who applied a gel containing 1% collagen hydrosolate extracted from chicken stomachs exhibited increased skin hydration and elasticity and decreased wrinkles and roughness. Thus, the collagen flooding the skincare market is, indeed, backed by science!

Drinking Collagen

Side bar: I was inspired to write this blog post when I saw an advertisement for drinkable collagen. I rolled my eyes, convinced it was a ridiculous Instagram trend, similar to skinny teas.

As it turns out, there is validity to ingesting collagen, and quite a few peer-reviewed journal articles back this practice. A study conducted in 2015 reports that middle-aged women who consumed 10 g of collagen per day exhibited increased skin moisture and collagen density. Another study displayed similar results, showing that low-molecular-weight collagen peptide oral supplements increased skin moisture and reduced wrinkles.

Other uses

Although collagen is synonymous with skincare, collagen plays other pivotal roles in our bodies. In fact, collagen is our most abundant protein. Ongoing research suggests collagen supplementation may assist with bone regeneration, wound healing, and arthritis treatment.  

Author's note

This post is by no means a comprehensive literature review of collagen in skincare. Many additional studies agree with the publications mentioned here. So the next time you reach for a skincare product with collagen, have faith that collagen products aren't so psuedosciency after all. 

Author

Kerry McPherson, @KerrySilvaMcph 
PhD Candidate studying biomedical sciences. Researches proteins implicated in cancer chemoresistance. Bolded Science creator and editor. Also co-founded a STEM education outreach program at her University.