Bone broth is having its moment- paleo likes it, nut jobs who believe vaccines cause autism like it*, whoever the hell these people are like it, my nutritionist is a big fan. The idea seems obvious- bones are full of nutrients that hard to get, especially in the typical American diet, surely drinking bones would be good. Especially for calcium. Everyone knows bones have calcium.
I got suspicious when I noticed that the nutritional label on my broth** reported 0% of my RDA of calcium. I checked a few more brands, the top contender lists 2% calcium RDA and 4% iron/6 grams of protein. Most list 0. nutritiondata.self.com gives considerably better numbers, but no source. Their listing contains a good deal more fat (9g, as opposed to 0 in any of the commercial broth I’ve found) and a non-zero amount of carbs. None of the micronutrients they listed (vitamin C, a few Bs, iron, calcium, manganese) are fat soluble, but maybe there is something to preparing it at home.
Some of the websites touting bone broth list other substances that aren’t on nutritional labels but they believe are important. I am well disposed to believe this claim. There is no reason to believe science knows all the micronutrients we need, much less a USDA oriented towards the well being of farmers, not consumers. The specifically mention glycosaminoglycans, a class protein/sugar hybrid found in joints. This seems utterly plausible, but I was unable to find any numbers of this. At all.
I found one scientific paper on bone broth. It is in Korean***. It has some English but not enough for me to actually determine the micronutrient:protein ratio. Beyond that you have studies about the components of bone broth and the assumption that it will be absorbed in this form. For example this paper on collagen and rheumatoid arthritis (PDF). Given it has 60 people and RA is a cyclic disease, their results are actually pretty good, but that still leaves it open to any number of manipulations. The second best paper is a press relief on an informal study of chicken soup.
That leaves protein. Everyone agrees bone broth has serious protein, but unfortunately not the most important kind. Protein is made up of amino acids, of which there are two kinds: non-essential (which your body can manufacture) and essential (which you must take in via diet). The RDA for protein is 0.8 g/kg body weight, of which 0.1 g should be of the essential amino acids (there are per-acid requirements but I’m not tracking 9 individual requirements), so 20% is putting you ahead of the game, except that broth is missing two EAAs entirely. After 20 hours of cooking (see korean) paper, 25% of the amino acids are glycine. For comparison:
- The pumpkin-based protein powder in front of me is 20% essential amino acids (and has way more iron than broth)
- Whey protein is 60% EAAs.
- Soy is 34%
I have trouble digesting protein and find bone broth stunningly easy to digest, so this is still a win for me, but it’s a slam dunk.
While traveling I’m using bone broth powder, which I’m increasingly convinced is a fancy way of saying “bone-based protein powder”. I’m okay with bone based protein powder, although I might not have packed the pumpkin if I’d realized this.
Do you know what else is basically a protein powder? Cricket flour. They taste similar, cricket has a better amino acid profile (25% essential) and more trace nutrients (although I’m still tracking down how many more). It is also cheaper, which should make !broth feel bad.
I find it more plausible than the average miracle food that bone broth has effects beyond what you’d expect from a naive read of the nutrition facts, because I expect animal bone + meat to fulfill a broader range of requirements than some berry. I do feel better when I drink it, but a lifetime of digestive and chewing problems has given me a tendency to develop food security blankets, and broth is currently filling that role. Simply by being a security blanket that is not jelly beans or peanut butter cups****, broth is a health food for me, personally, but I can’t really extrapolate beyond that. The current press around it appears to be almost entirely groundless.
Once again, the state of nutritional knowledge is embarrassingly bad and I would like us to shift money towards increasing it. Also why the hell can’t I test the nutritional content of broth I make myself?
*To their credit, they have an explanation that doesn’t rely on mercury, which has been extremely thoroughly disproven. If they had presented it as a fringe thing they needed to prove, I would have entertained their hypothesis. They presented it as fact, without any attempt to distances themselves from the atrocious denialism of the mercury-based anti-vaxxers.
**I buy it frozen on the theory that my time and not having my house continually smell of meat was worth the extra money.
***I don’t think this would be hard to determine if you read Korean, volunteers would be welcome.
****Trader Joe’s brand- I’m not an animal.
ETA: I only just learned that bone broth means “bones + connective tissue”. Clean bones give you hardly any protein, even if there’s marrow in them. Apparently I don’t need to pay $10/bag for store made stuff, I can use $8 worth of chicken feet and liver and eat for a week.