Does bone broth actually do anything for your bones?

In an animal study, chicken and vegetable bone broth inhibited the activity of bone-resorbing cells. Rats that received broth or an extract of it daily had higher bone density and greater bone volume than rats that received no broth. The substances thought to be responsible are hyaluronic acid and chondroitin sulfate, compounds that occur naturally in joints and connective tissue.

Additional laboratory research showed that the fraction of the broth richest in hyaluronic acid and chondroitin sulfate was the most effective at preventing precursor cells from developing into bone-resorbing osteoclasts. This points to a mechanism of action, but laboratory results do not always translate into effects in a living organism, let alone in humans.

There are no clinical studies in humans. What works in rats with surgically induced hormonal deficiency does not necessarily produce the same effect in a healthy person or in someone who is postmenopausal. How much hyaluronic acid and chondroitin sulfate is present in an ordinary cup of homemade broth, and whether that is enough to have any effect, cannot be determined from these studies.

For bone health, there are interventions with a far stronger evidence base in humans, such as adequate calcium and vitamin D, exercise, and medication for osteoporosis where appropriate. Bone broth is not harmful and can be a perfectly fine part of a varied diet, but the expectation that it strengthens your bones is not yet based on research in humans.