Collagen: what is the evidence? Does it really work or is it an expensive fad?

I’ve talked about collagen quite a bit on here and I take a collagen peptides powder myself every day. I’ve looked into the research and I’m convinced. However, as I always explain to my clients, it is not as simple as taking collagen and having it neatly land in the collagen structures in your skin, joints and bones. There is so much more to the process than this.

Recently we’ve seen high-profile doctors and pharmacists on social media saying collagen doesn’t work, alongside headlines such as “collagen won’t stop wrinkles.” (Spoiler alert: when you read the papers behind the headlines, they actually show benefits in skin elasticity, hydration and joint symptoms, just not miracle wrinkle erasure)

So what is the truth?

Let’s start with the biology, because the sceptics are not wrong about the basic digestion process.

What happens when you take collagen?

Firstly, you need to understand that collagen is a protein that is a component of the connective tissue and structure in the body. Collagen supplements are simply animal collagen that have been manufactured into a powder, liquid, capsule or gummy.

When you consume collagen in supplement form, your digestive system breaks it down, just like it would any other protein, into:

• individual amino acids (the basic building blocks of protein)
• small di- and tri-peptides (two or three amino acids joined together)

As the collagen critics correctly say, your body can use those amino acids for any purpose it needs. It doesn’t automatically send them to the collagen structure in your skin, bones and joints.

You should also be aware that your body is perfectly capable of making its own collagen from amino acids obtained from any protein source.  It does this very well in younger years but once you reach your 40’s and beyond, the rate of collagen creation that occurs naturally in the body, falls and we break down more collagen than we make, hence we see changes in the structure in the skin, hair, nails and joints (think reduced skin elasticity, joint aches, weaker nails and thinner hair).  During menopause and beyond, the rate of collagen production falls rapidly and so in many women these symptoms can come on quite quickly.

Interestingly, despite the fact that the amino acids and peptide chains from collagen supplements could be directed anywhere in the body, there are multiple studies showing benefits from collagen supplementation. We need to be clear here that many of these studies are industry funded and so may not be free from bias, however, a scientific review published just last week, by Anglia University, concluded that collagen has credible benefits when used over time, particularly for skin elasticity and osteoarthritis.

So how is this the case if the amino acids and peptide chains from collagen supplements could be directed anywhere in the body? 

There are a few possible explanations:

To understand the explanations, it is important to understand that collagen is not ‘just another protein’. Collagen has a very distinct amino acid profile. It is particularly rich in the specific amnio acids :

• Glycine
• Proline
• Hydroxyproline

These are the exact amino acids your body needs in high amounts to build the triple-helix structure of collagen in your body.

Many women are low in their overall protein intake, and very few diets provide these specific amino acids in meaningful quantities on a daily basis.  So, collagen peptides may help in two key ways:

1. Substrate supply (providing the raw materials)

To make collagen, your fibroblast cells (the main cells responsible for making collagen) need:

• Glycine
• Proline
• Hydroxyproline
• Vitamin C
• Iron
• Copper

Collagen peptide supplements, increase the availability of the specific building blocks required for collagen synthesis. Importantly, there is evidence that glycine may be a rate-limiting amino acid for collagen production, meaning that it is the required amnio acid that is in shortest supply and so controls how much of the final output can be achieved.  Collagen is about one third glycine. In modern diets we eat lower amounts of glycine as we consume less skin, bone broth and slow cooked meats which are the most abundant food sources.  We also use glycine for detoxification and sleep production and so the amounts we do get from food may all be being used up for these purposes.   

So, one explanation for the reported benefits of collagen supplementation is simply supplying the right raw materials in meaningful amounts. This is may be especially relevant for:

• women with low protein intake due to food preferences, busy lives and budget considerations
• perimenopause and post-menopause (collagen naturally declines)
• women with higher requirements for detoxification or with stress and poor sleep (due to greater need for glycine for other functions not collagen production)
  

2. Cell signalling

When collagen peptides from supplements are digested, there is evidence that some small peptides chains, particularly Pro-Hyp (proline plus hydroxyproline), are absorbed intact and enter the bloodstream as a di-peptide, rather than being fully broken down into individual amino acids. These di-peptides appear to act as biological signals, not just nutrients.  Research suggests they can:

• stimulate fibroblast activity
• increase collagen type I and III production
• support extracellular matrix formation
• increase hyaluronic acid synthesis

In simple terms, they may “switch on” collagen producing cells. This mechanism is very specific to the amino acids and peptides in collagen and is very different to food sources of collagen such as chicken breast, fish or eggs.

Exercise synergy

There is emerging evidence that collagen taken before exercise may increase collagen synthesis in tendons, ligaments, joint connective tissue. This fits with what we know about mechanical loading stimulating collagen production.

So collagen peptide supplementation, along with movement and vitamin C is likely to be far more effective than collagen alone.

What does the human research on collagen supplementation show? 

Randomised controlled trials are available that show benefits for:

• Skin : improved elasticity, improved hydration, increased dermal collagen density (in some studies)
• Joints : reduced joint pain in athletes, symptom improvement in mild osteoarthritis

What we don’t see is instant wrinkle removal or dramatic structural change. Headlines have focused on this fact for click bait, and in my opinion, wrongly giving the impression that collagen does not bring any benefits at all. 

Who is most likely to benefit from collagen supplementation?

In my experience and taking into account the available research, the people who tend to respond best are:

• those with low protein intake (although if very protein deficient, the body may prioritise other functions first over collagen production so results may take longer to be achieved)
• perimenopausal and postmenopausal women
• active women with joint or tendon issues
• those working on skin health alongside nutrition and lifestyle

Key nutrients matter

Collagen synthesis cannot happen without cofactors, particularly:

• Vitamin C (essential for hydroxylation)
• Copper
• Iron
• Adequate total protein intake

Without these, collagen peptides alone will have limited impact.  You don’t need to take all these together in one collagen supplement as your diet may be delivering all you need. My advice is to chat to a registered nutritional therapist who can assess this for you and recommend an ethical collagen supplement of an appropriate dosage and absorbability, and also advise on your levels of the other required co-factors.  This service is offered for free at Amaranth, book online at www.amaranth-wellbeing.com or here.

So what is my conclusion?

The sceptics are right about the digestion process, collagen is broken down and not magically delivered to your skin.

However, the full picture is more nuanced.  Collagen peptides may:

• increase intake of the specific amino acids needed for collagen production in the body
• provide bioactive peptides that stimulate collagen-producing cells
• support connective tissue when combined with exercise and vitamin C
• help women reach adequate daily protein intake

This explains why we see modest but consistent benefits in clinical trials. I don’t believe that collagen is a miracle supplement, but I am convinced enough that I add it to my daily routine. I have taken a collagen supplement for the past five years and my observation is that it has slowed the rate of aging in my skin, I have strong hair and nails and I don’t have any joint aches and pains. I am in my peri-menopausal years and so this is the time I would expect to have seen symptoms in these connective structures.

A few practical considerations

• The brand, dosage and particle size matter, Choose a hydrolysed collagen peptide powder from grass fed or wild caught sources, with extensive testing reports or certifications.
• Take it consistently for at least 8–12 weeks, your body needs time to use the supplement to create it’s own collagen structure.
• Ensure adequate vitamin C, iron and total protein intake in your daily diet. This provides the co-factors for collagen production and ensures that your body can use dietary protein for other essential functions and then those specific collagen amino acids for collagen formation.
• Combine with resistance training or regular loading exercise to maximise the benefits.

If you’d like to know which collagen products I recommend in clinic and why then drop an email to hello@amaranth-wellbeing.com or book a free health review for personalised recommendations.