Answer:
To get the most nutritional benefits, it is supposed to be homemade, not store bought. That translates into boiling animal bones (fish, poultry, beef) with water, vegetables, herbs and spices. You are advised to soak the bones in vinegar prior to boiling to help leech minerals from the bones into the water. The broth needs to be cooked longer than a simple soup, anywhere from four to 48 hours. The bones are boiled long enough that they start to disintegrate and release nutrients and proteins, like calcium, phosphate and collagen, in higher amounts than what is found in regular broths.
So, is it worth the work involved?
People claim that by drinking bone broth, they have cured chronic diarrhea, constipation and even some food intolerances. Some claim the gelatin found in bones is the reason. There really is no conclusive research to support these claims. However, sipping on broth throughout the day is a good way to stay hydrated.
Another supposed benefit of drinking bone broth is that it improves the immune system and reduces joint pain and inflammation. This claim is that bone broth contains high amounts of minerals, such as calcium, magnesium, phosphorus, silicon, sulfur chondroitin, glucosamine and a variety of trace minerals. It just isn't clear how much of each nutrient broth contains. Research by one author suggested that one cup of bone broth contains 20-30 mg of calcium. The daily recommended value for men and women, ages 19-50 years old, is 1000 mg per day, so this does not appear to be a high calcium food choice.
Dawn Jackson Blatner, a Registered Dietitian, sums it up nicely, "It's not a miracle cure like some outlets talk about, but it is still a good-for-you food." I agree with her. If you want to grab a trendy cup of bone broth for a snack, I still think it could be a good idea. It's low in calories, low in fat and does have some nutritional value. It is definitely a better choice than a sugary coffee drink.