Posted on Mon, 7 Jan 19
Investigators recently set out to determine if bone broth would provide clinically significant levels of collagen or collagen precursors.
Despite its increasing popularity as a health food, bone broth (more commonly known as stock), has little scientific evidence to support any popular health claims.
One of the main suggested health benefits is that bone broth is a good source of collagen, so a research team set out to see if a typical 250 ml serving would provide clinically meaningful amounts of collagen components (hydroxyproline and hydroxyproline) and collagen forming amino acids (glycine, lysine, leucine, and proline).
In total, 28 store-bought, café-bought and home-prepared samples were tested, and levels compared to a reference dose of 20 g as this is a typical dose used in existing collagen synthesis research.
It was found that most bone broths provided significantly lower levels of collagen components and collagen forming amino acids than that shown to be clinically able to improve collagen synthesis. For example, all but one provided combined hydroxyproline and hydroxyproline below 1 g, and most provided leucine below 500 mg and all were below 2 g.
Contrary to the popular suggestion that vinegar increases collagen content the addition of vinegar did not increase amino acid content, however longer cooking may improve levels with the bone broth that was cooked the longest (72 vs. 24 hours) having the greatest content of amino acids.
“This study demonstrates that it is possible to consume similar amounts of key amino acids found in collagen protein from certain bone broth preparations in similar amounts as those provided in a therapeutic dose of collagen supplements; however, it is an unlikely and potentially unrepeatable outcome,” commented the study authors. Compared to other sources of amino acids, such as purified protein, amino acids, or food sources, the dose would be impractical and unreliable. “…despite its promoted benefits, bone broth does not appear to provide a consistent or optimal source of such nutrient support,” they concluded.
However, they did note that it is possible that the relatively low amounts of collagen and collagen forming amino acids in bone broth may be revealed to be clinically relevant with more research.
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. Int J Sport Nutr Exerc Metab. 2018 Sep 26:1-8. doi: 10.1123/ijsnem.2018-0139. [Epub ahead of print]