Bone broth has been prescribed as medicine for thousands of years. Modern science is finally explaining why.
From 12th-century physician Maimonides recommending chicken soup for respiratory illness to traditional Chinese medicine using bone stocks to support the kidneys and blood, cultures around the world independently arrived at the same conclusion: slow-simmered bones produce something healing.
Today, bone broth is a $4 billion industry. It's been called a superfood, a gut healer, a joint saver, and a beauty elixir. Skeptics call it overpriced soup. The truth—as usual—is more interesting than either extreme.
What's Actually In Bone Broth?
When you simmer bones for 12-48 hours, heat and acidity (usually from a splash of vinegar) break down connective tissue and leach minerals from the bone matrix. The result is a liquid containing:
- Collagen and gelatin — the structural proteins that form your skin, gut lining, tendons, and cartilage
- Glycine — an amino acid critical for detoxification, sleep, and anti-inflammatory signaling
- Glutamine — the primary fuel source for intestinal epithelial cells
- Proline and hydroxyproline — amino acids essential for collagen synthesis
- Minerals — calcium, magnesium, phosphorus, and potassium in bioavailable forms
- Glycosaminoglycans (GAGs) — including chondroitin sulfate, glucosamine, and hyaluronic acid
The exact concentrations vary wildly depending on the bones used, cooking time, and preparation method. This is where some of the confusion begins.
The Real Benefits (Backed by Evidence)
Gut Repair and Intestinal Permeability
This is where bone broth has its strongest functional medicine case. Glutamine is the single most important nutrient for maintaining the integrity of your intestinal lining. It fuels the rapid turnover of enterocytes—the cells that form your gut barrier.
A 2017 study in Clinical and Experimental Immunology confirmed that glutamine supplementation reduces intestinal permeability in critically ill patients. Functional medicine practitioners have used glutamine-rich foods, including bone broth, as a foundational gut-healing intervention for decades.
Gelatin also plays a role. Research shows it enhances gastric acid secretion and supports the mucosal lining of the stomach—making bone broth a legitimate recommendation for patients with gastritis, reflux, or post-antibiotic gut recovery.
Joint Support
Bone broth naturally contains type II collagen, chondroitin sulfate, and glucosamine—the same compounds sold as joint supplements.
A 2016 study in the British Journal of Sports Medicine found that collagen peptide supplementation significantly reduced activity-related joint pain in athletes. Conventional rheumatologists increasingly acknowledge that collagen supplementation can complement standard treatment for osteoarthritis.
The caveat: commercial bone broth varies enormously in collagen content. A cup of homemade broth simmered for 24+ hours with knuckle bones and feet will contain far more collagen than a quick-cooked commercial version.
Glycine: The Underrated Amino Acid
Glycine may be bone broth's most valuable and least discussed component. This amino acid:
- Supports Phase II liver detoxification (conjugation of toxins for elimination)
- Acts as an inhibitory neurotransmitter, promoting calm and improving sleep quality
- Reduces inflammation by suppressing activation of immune cells
- Is required for glutathione synthesis—your body's master antioxidant
A study in Sleep and Biological Rhythms showed that 3 grams of glycine before bed improved subjective sleep quality and reduced daytime fatigue. A single cup of well-made bone broth can provide 2-3 grams of glycine.
Where the Hype Outpaces the Science
Mineral Content Is Modest
Despite popular claims, bone broth is not a significant source of calcium or magnesium. A 2017 analysis in Food and Nutrition Research found that homemade bone broth contained relatively low mineral concentrations compared to daily requirements. You'd need to drink several quarts daily to meet your calcium needs from broth alone.
This doesn't mean the minerals aren't valuable—they're in highly bioavailable forms. But bone broth should complement a mineral-rich diet, not replace one.
Collagen Doesn't Go Straight to Your Skin
The beauty industry markets collagen as a direct skin-plumping agent. The reality is more nuanced. When you consume collagen, your body breaks it down into amino acids and peptides. These are then redistributed wherever your body needs them most—which might be your gut lining, not your crow's feet.
That said, several randomized controlled trials do show measurable improvements in skin elasticity, hydration, and wrinkle depth with consistent collagen supplementation over 8-12 weeks. The benefit is real; it's just not as direct as the marketing implies.
Lead Contamination Concerns
A frequently cited 2013 study found that organic chicken bone broth contained measurable amounts of lead. This is a legitimate concern—bones do accumulate heavy metals. However, subsequent analyses showed that lead concentrations in bone broth are generally well below EPA drinking water limits, especially when using bones from pasture-raised animals.
If you're concerned, source your bones from quality producers and rotate bone broth with other gut-healing foods rather than drinking it as your sole beverage.
How to Get the Most Out of Bone Broth
If You're Making It at Home
- Use joint-rich bones: knuckles, feet, oxtail, and necks contain the most collagen
- Add 1-2 tablespoons of apple cider vinegar to help extract minerals
- Simmer for at least 12 hours (24+ for beef bones)
- A good broth will gel when refrigerated—that's the gelatin, and it's your quality indicator
If You're Buying It
- Look for brands that list protein content of 10+ grams per serving
- Avoid products with added fillers, sugars, or "natural flavors"
- Check that it gels when chilled—many commercial broths are glorified stock
Therapeutic Use
In a functional medicine gut-healing protocol, bone broth is typically used as one component of a comprehensive approach that includes removing trigger foods, replenishing digestive enzymes, reinoculating with probiotics, and repairing the gut lining. It's powerful, but it's not a solo act.
The Verdict
Bone broth is not magic, but it's not just soup either. It's a genuinely nutrient-dense, therapeutic food with real clinical applications—particularly for gut repair, joint support, and glycine repletion. The key is having realistic expectations and using it as part of a broader strategy.
Your grandmother wasn't wrong about chicken soup. She just couldn't explain the glutamine, glycine, and glycosaminoglycan mechanisms. Now we can.