§ Claim under review · Mixed
"Bone broth provides up to 92% of the amino acids the body uses to form collagen, which supports intestinal repair" — supported in the post by: "A 2019 scientific review confirmed that bone broth is a potent natural source of the exact building blocks the body needs to synthesize its own collagen," citing "Alcock, R. D., Shaw, G. C., & Burke, L. M. (2019). 'Bone Broth as a Rich Source of Nutrients: A Review of the Evidence and a Call for Further Research.' ACSM's Health & Fitness Journal, 23(1), 20-25."
Verdict
False
Confidence
MediumSummary
This post is not accurate. The "92% of the amino acids the body uses to form collagen" figure does not appear in any scientific source I could find, and the study the post names as proof actually concluded the opposite. Researchers Alcock, Shaw and Burke did publish on bone broth in 2019, but their paper was titled "Bone Broth Unlikely to Provide Reliable Concentrations of Collagen Precursors," and it found that bone broth contained significantly lower levels of collagen-building amino acids than collagen supplements, with huge variation between batches and recipes. The post also cites the wrong journal and a title that does not appear to exist. Bone broth genuinely does contain glycine and proline, and those amino acids are studied in relation to gut barrier health, but mostly in animal and laboratory research rather than trials of people drinking broth. There is no published human trial showing that drinking bone broth repairs the intestinal lining or firms skin. The post ends by directing readers to message for a paid gut health guide, which is worth keeping in mind when weighing how confidently it states its case.
The readings
key figures from the evidenceclaimed amino acids bone broth provides for collagen
significance of lower hydroxyproline, glycine, proline in bone broth
bone broth protein content by weight (retailer marketing claim)
Why this verdict
Evidence
The three authors named in the post did publish a real 2019 paper on bone broth and collagen. Its conclusion is close to the opposite of what the post says it confirms.
The study analyzed commercial and laboratory-prepared bone broths for the key collagen-related amino acids. It analyzed commonly consumed preparations of bone broth to assess the amount and consistency of its amino acid content, with commercial and laboratory-prepared samples, made with standardized and variable (nonstandardized) protocols, analyzed for glycine, lysine, proline, leucine, hydroxyproline, and hydroxylysine.
The main finding was that amino acid concentrations in bone broth made to a standardized recipe were significantly lower for hydroxyproline, glycine, and proline (p = .003) and hydroxylysine, leucine, and lysine (p = .004) than those provided by comparator collagen supplements.
On consistency, there was large variability in the amino acid content of bone broth made to nonstandardized recipes, with the highest levels found in café-prepared varieties, and for standardized preparations, commercial bone broths were lower in all amino acids than self-prepared varieties. The authors' own bottom line: if the intake of collagen precursors is proven to support the synthesis of new collagen in vivo, it is unlikely that bone broth can provide a consistently reliable source of key amino acids, and research on the provision of key amino acids from dietary sources should continue to focus on the standard sources currently being researched. Note the conditional "if ... is proven," which signals the authors did not treat collagen synthesis from dietary precursors as settled.
Independent coverage describes the same finding: a 2019 study analyzed laboratory-prepared samples of bone broth and found that bone broth is unlikely to provide sufficient concentrations of collagen precursors, in the form of specific amino acids, to support the claimed benefits.
On the gut portion of the claim, there is a real and recent review, but its evidence base is about nutrients found in broth rather than trials of broth itself. The 2025 Digestive Diseases and Sciences review reports, through reviews of animal and human studies, that bone broth includes amino acids (glutamine, glycine, proline, histidine, arginine) and minerals (Ca, P, K, Mg, Zn) that are beneficial, and that the benefits documented for components in bone broth support enhancement of gut health and improved intestinal barrier function. That is a claim about components, tested largely in animals, not a demonstration that drinking broth repairs a human intestine.
Mainstream health publishers remain cautious. WebMD states that several popular claims about the benefits of bone broth may be overstated, and that so far there is no scientific evidence that bone broth can relieve joint pain, make skin firmer, improve digestion, or strengthen bones.
On the number 92%: no scientific source containing this figure was located. The closest match found anywhere is a bone broth retailer's marketing page stating that by weight, bone broth is 92% protein while collagen is around 90% protein . That is a completely different measurement (protein as a share of dry weight of a powdered product) and has nothing to do with "92% of the amino acids the body uses to form collagen." No peer-reviewed source was found stating that bone broth supplies any such percentage of collagen-forming amino acids.
Findings
✓ What's accurate 4
- Bone broth does contain collagen-derived amino acids including glycine and proline. Bones are rich in collagen and therefore broth is too, and collagen can be digested to yield glycine and proline.
- Alcock, Shaw and Burke are real researchers who published a real 2019 paper specifically about bone broth and collagen precursor amino acids.
- Endogenous collagen production does decline with age, and collagen is a structural component of both skin and the intestinal environment. This is uncontroversial background biology.
- Amino acids found in bone broth, particularly glutamine and glycine, are genuinely studied in connection with gut barrier function. These amino acids have been shown to support cellular repair and maintain the integrity of the gut barrier.
≈ What's misleading 7
- **Fabricated or unsourced statistic.** The headline figure "up to 92% of the amino acids the body uses to form collagen" appears in no scientific source located. It is not in the Alcock paper, which found bone broth amino acid levels significantly *lower* than comparator collagen sources. The only "92" found in searching was a retailer's claim about protein content by weight, a different quantity entirely.
- **Citation misattribution / reversal of source meaning.** The post's cited reference does not exist as described, and the real paper by those authors concluded bone broth is *unlikely* to be a reliable source of collagen precursors. Presenting this research team as having "confirmed" bone broth's potency inverts their finding.
- **Omitted qualifier (variability).** The single most important finding of the real study, that amino acid content varies enormously between preparations and that commercial broths are the weakest, is absent from the post.
- **Exaggeration and false certainty.** "Confirmed," "validated by modern science," and "the precise nutrients" overstate a laboratory composition analysis. The authors themselves wrote conditionally, saying "if" precursor intake is proven to support collagen synthesis.
- **Unsupported causal chain.** Contains amino acids → body makes collagen → gut lining is repaired and skin firms up. Each arrow is an assumption. Ingested amino acids are absorbed into a general pool and allocated by the body; they are not directed to the gut wall or the dermis.
- **Species and setting extrapolation.** Much of the supportive gut barrier literature is animal or cell based. The post presents it as established human outcome.
- **Marketing as evidence.** The scientific citation functions as authority decoration for a lead-generation offer rather than as a source that was actually read and represented.
? What's uncertain 4
- Whether the cited ACSM's Health & Fitness Journal article exists in some form could not be fully resolved. Searches of the exact title, the journal, and the volume returned nothing matching. My search budget was exhausted before I could inspect the full January/February 2019 table of contents directly. I am treating the citation as unverified rather than definitively fabricated.
- The true origin of the "92%" figure is unknown. I found no source stating it in the form the post uses.
- Whether bone broth consumption measurably changes human intestinal permeability is not established. I found no human trial testing bone broth itself on that endpoint, and one secondary source asserts none exists, but absence of a trial in my searches is not the same as proof that none exists.
- The quality of the 2025 Digestive Diseases and Sciences review (narrative vs systematic, funding, author affiliations) was not assessed beyond its abstract. ---
Sources
4 of 6 linked to records**Alcock RD, Shaw GC, Burke LM. "Bone Broth Unlikely to Provide Reliable Concentrations of Collagen Precursors Compared With Supplemental Sources of Collagen Used in Collagen Research." International Journal of Sport Nutrition and Exercise Metabolism, 2019;29(3):265-272**
**"Bone Broth Benefits: How Its Nutrients Fortify Gut Barrier in Health and Disease," Digestive Diseases and Sciences (2025)**
**National Geographic science coverage of bone broth evidence**
**Cleveland Clinic and WebMD consumer health explainers**
**Bluebird Provisions (commercial bone broth retailer) blog**—WEAKEST
**The cited reference itself ("Bone Broth as a Rich Source of Nutrients: A Review of the Evidence and a Call for Further Research," ACSM's Health & Fitness Journal 23(1):20-25)**