Debunking bone broth

Monday, Oct. 16, 2017

We’ve all seen the rise and fall of many tonics and cure-all products, but there is a niche of products and practices that seem to make a ‘comeback’ over and over again. These repeat offenders range in risk from innocuous to downright dangerous. Scholars have sought to demystify various snake-oils and miracle tonics, and yet today there is a greater prevalence of these mysterious healing items than ever before. So, let's examine one of the oldest and most resilient healing products, which has resurfaced recently – bone broth.

The saying goes something along the lines of "a good broth will raise the dead." 

Bone broth, or stock, is made by boiling bones (often marrow bones or those with lots of connective tissue) in water until it’s imbued with desirable micronutrients and minerals. The broth can be used as a base for soups and stews, can add extra flavor and nutrients to grains (rices, pasta, quinoa,  etc.) when used in place of water, but the latest iteration of the bone broth elixir trend can be found in hip paper coffee cups in drive-thrus and takeaways. Popular talk show host and comedian Joe Rogan swears by his morning cup of bone broth; he even occasionally kicks it up a notch with a spoonful of hot sauce.

The benefits of bone broth have been under scrutiny for nearly a hundred years, and scientists have found mixed results. A nutritional analysis performed by British nutrition scientists Robert McCance and Elsie Widdowson, published in 1934, revealed that traditionally prepared bone broth didn't pack the nutritional punch its supporters claimed.  At roughly 10mg of calcium and 2mg of magnesium withdrawn from 100g of bones over 9 hours, you'd get nearly 5 times as many bone-building minerals from a single serving of broccoli (47mg of calcium per 100g and 21mg of magnesium per 100g of  broccoli). 

bowl of broccoli

It seems clear that bone broth is not the nutritional powerhouse it was introduced as, but mineral content isn't the only health claim made on behalf of the elixir. Another frequently cited benefit is that the collagen drawn from the bones and connective tissues is used by the body to repair collagen found in joints, skin, hair, and our own bones. This claim can be broken down into several components, much like collagen is broken down into its constituent amino acid building blocks during digestion, and no whole collagen molecules enter the bloodstream from digested food. 

While it stands to reason that giving the body collagen to break down will create an abundance of the components used later to build new collagen in the body, it is not clear that collagen production is positively influenced by the supplementation of dietary collagen. This is likely because the limiting factor in collagen production is not the presence of the required amino acids, rather, something else is gradually decreasing our collagen content as we age. 

Let me get this straight, it’s low in nutrients and minerals, and we don't use the collagen to repair our joints, so what is bone broth good for? 

The good news is that there are some legitimate claims, and with evidence to back them up! A study published in 1978 found sipping hot chicken broth increased the rate which mucus flows significantly more than hot or cold water, so there is some testable truth to the age-old axiom that chicken soup helps to soothe a cold. In addition to helping unclog your nose and sinuses, it also turns out that chicken soup broth inhibits the activity of neutrophils. Neutrophils are the white blood cell equivalent of an emergency first responder, they are like the firefighters who arrive to every 911 call. Even though they aren't equipped to handle every situation, firefighters arrive to most 911 calls first because there is less distance covered by each fire station than each hospital or police station, so there is a good chance that a fire truck is the closest emergency crew wherever you are calling 911 from. Neutrophils circulate in the blood and migrate to wherever an infection is detected to release signal molecules which increase the inflammatory effect of the next wave of white blood cells. These cells play an important role in our immune response, but they can sometimes overdo it and we end up feeling uncomfortably stuffy, sinuses swell shut and throb, mucus thickens, and fever. We’ve always known chicken soup to help with the symptoms of a cold, but now thanks to a study published in 2000 we understand how and why it helps, which could lead to the development of new medicines. 

If you’re on the hunt for the next superfood, keep it moving because the evidence for bone broth just doesn’t cut it. If, on the other hand, you have a cold or issues with inflammation, you can confidently simmer those chicken bones with the knowledge that the end result will help you feel better. If you would rather cook your rice in chicken stock than water, you can also proceed with gusto! As far as cure-all magic elixirs go, bone broth underwhelms on all fronts except to provide some relief from the symptoms of cold and fever. But if flavour is your pursuit, a rich bone broth stock makes a mighty fine tool on your culinary tool belt though!

1934 Nutritional Analysis of Bone Broth:  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1975347/
Chicken soup inhibits Neutrophils: https://www.ncbi.nlm.nih.gov/pubmed/11035691
Chicken soup relieves mucus related symptoms: https://www.ncbi.nlm.nih.gov/pubmed/359266
Collagen content in osteoporosis: https://www.ncbi.nlm.nih.gov/pubmed/15951132
Bonus: Blueberry consumption inhibits OVX-induced bone cell senescence:  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3636388/