20 more questions about the benefits of collagen supplements

A few weeks ago, I answered 20 of your burning questions about collagen. Today I’m back for part two of this series with 20 MORE questions.

Before I start, let me make a general disclaimer so I don’t have to sound like a broken record: in order to offer an optimal supplementation strategy with confidence, you need fairly extensive evidence to fall back on. While collagen is a hot topic, there hasn’t been a lot of research on collagen supplementation, especially no human studies. That doesn’t mean we’re shooting blind here. We know that collagen was once abundant in the human diet, and we need collagen to balance the methionine we get from meat. There is also is a growing (but not yet extensive) literature on collagen supplementation, as well as a slew of studies aimed at understanding the effects of certain amino acids – especially glycine – found in collagen.

All of this means that while I can give my opinion on best practices, some of the questions you ask require data that we just don’t have yet. I am confident that it is coming. In the meantime I have been able to read the following from the available science.

What types of collagen are best for joints and skin?

The skin mainly contains type I and type III collagen. Cartilage is type II. However, collagen preparations all contain the same basic amino acid building blocks. There is no evidence that one formulation is better than another for achieving any particular goal. You probably don’t have to worry about micromanagement.

How is collagen supplementation related to the use of glucosamine and chondroitin for joint health? Do we need both?

They fulfill different functions. Glucosamine and chondroitin are used to prevent cartilage breakdown and relieve joint pain, although the evidence for their effectiveness is mixed. Collagen provides amino acids that are necessary to build collagen in the body. I do not know if you need both, but you can take them together.

Does Topical Collagen Work?

Collagen peptides are too large to penetrate the skin effectively, and there is virtually no evidence that topical collagen products have antiaging or other cosmetic benefits. However, some medical applications are quite promising. In particular, I keep an eye on research on collagen-based biomaterials to accelerate wound healing.

Is Collagen Good For Gut Health? Does collagen heal the gut?

“Heals the Gut” may seem like too strong a promise, but the available data suggests that collagen is beneficial for gut health. In particular, studies show that glycine – the primary amino acid in collagen peptides – has anti-inflammatory and cytoprotective effects in the gut. Glycine also protects against endotoxemia and ulcers.

For joint health, is there a specific collagen supplement protocol that you recommend? How much do I have to take, how often and in what form to support joint health?

As I said above, we don’t have the fine-grained studies that we would need to answer this question. The few human studies available suggest that 10 grams of collagen peptides or 10 mg of undenatured type II collagen may be enough to get some benefits.

Does Collagen Supplement Help With Prolotherapy?

I like this hypothesis, but I don’t know anyone tested it. In prolotherapy, doctors inject an irritant around damaged connective tissue that is said to trigger the deposition of new collagen tissue. It seems like in this situation you want as many amino acids available as possible. Why not try

Do collagen peptides accelerate wound healing and if so, in what amount?

Based on the evidence available, I’m pretty confident that the answer is yes. However, a 2019 review found only eight studies of collagen peptides worth considering – not nearly enough to answer the second part of that question. Topical collagen treatments also continue to show promise, but they are currently still experimental.

Can collagen accelerate recovery time in the case of broken bones, cancer metastases, or other serious injuries?

Another good hypothesis to test. Here’s what we know: Bone consists primarily of type I collagen. Collagen supplement appears to improve bone mineral density and protect against age-related bone loss. Vitamin C, an important cofactor for collagen production, supports bone healing after injuries. I personally would try.

Can pregnant women take collagen? Should you?

I see no reason why not, nor does any of the major (American) medical associations seem to have a problem with it. Some sources recommend avoiding marine collagen during pregnancy due to possible sensitivities, but doing so can be a great caution. Talk to your doctor if you are concerned.

Can Breastfeeding Women Use Collagen Supplements?

Same as above. Pregnant and breastfeeding women need these amino acids. In addition, collagen bone broth, soups and stews made from meat on the bone are traditional postpartum foods around the world. Ancestral wisdom at its finest! Always choose reputable brands that test their collagen for impurities. (Yes, Original cuisine does.)

Should you be consuming more collagen as you get older? Are Different Forms Of Collagen Better For People Of A Certain Age?

Older people need more protein to stimulate muscle protein synthesis. In particular, they need more of the amino acid leucine. Although collagen contains some, meat is a better source. However, the elderly should consider adding collagen for bone health. All collagen peptides are sufficient.

Advantages for endurance athletes to support ultra runs and other endurance events? Are there other endurance benefits beyond joint health?

This is a slam dunk in my opinion. See the “Collagen for Performance” section in this post. In addition to joint and connective tissue health, supplementation with collagen can have a positive effect on body composition and, according to a study, improve muscle strength and endurance.
Glycine also supports sleep, which is critical to recovery.

I think collagen powder is quite high in oxalates. For those of us who need to minimize our oxalate intake, is there a decent alternative?

The amino acid hydroxyproline is a precursor to oxalate production in the liver. All collagen supplements (and bone broth) contain hydroxyproline. Talk to your doctor before taking any supplement if you are prone to calcium oxalate kidney stones. You might be ok with smaller servings. Stand-alone glycine supplements are another option (see below).

Can you be allergic to collagen? My 16 year old daughter gets itchy throat from using collagen powder.

That definitely sounds like an allergic reaction. There have been some documented cases of collagen allergies, although they appear to be quite rare. People with fish and shellfish allergies should stay away from marine collagen. Does the powder in question contain any other ingredients? In any case, she should stop doing it.

Do I have to worry about heavy metals like lead in collagen supplements?

With all supplements, you want to make sure that you are buying from a trusted source that follows best safety practices. Our quality standards at Primal Kitchen include testing every batch of the collagen produced for compliance with government standards for heavy metals.

Does adding collagen to your coffee (but nothing else) officially break your fast? Is it important?

I have a whole post on what supplements do and don’t break a fast. To quote myself: I say “technically yes” but “realistically no, collagen doesn’t break the fast.” There is a slim possibility that glycine could inhibit autophagy, but I’m not too concerned about that.

If I am tracking macros, should I be tracking collagen peptides in terms of my total protein?

No. Collagen is considered an incomplete protein because it lacks tryptophan, one of the essential amino acids. It’s also a relatively poor source of leucine when compared to meat or whey protein. Your food tracking app counts collagen as part of your daily protein content, so you need to mentally subtract it.

I’ve heard that collagen can lower serotonin levels and cause increased anxiety in some people. Is that true?

Collagen peptides lack tryptophan, a precursor to serotonin. Failure to consume enough complete sources of protein can lead to tryptophan deficiency. Collagen does not use up Tryptophan, so collagen supplementation shouldn’t cause low serotonin levels. Just don’t replace other sources of protein with collagen.

Glycine powder is much cheaper than collagen and is actually very tasty (naturally sweet). Do you think supplementing 10-15g glycine can achieve most of the benefits of collagen supplementation?

I also have a contribution to this. The short answer is, I am for adding glycine if you want, but it won’t bring you all of the benefits of collagen. Keep in mind that collagen is the only sensible food source for hydroxyproline, which is essential for collagen synthesis in the body.

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