Bone Broth

Bone Broth: The Culinary Marathon That Builds Health From the Ground Up

Bone broth (in Hebrew “מרק עצמות”) is the product of long cooking (6–24 hours) of animal bones — usually beef, chicken, fish or lamb — together with vegetables, herbs and an acid (usually apple cider vinegar). The long cooking process breaks down connective tissue, cartilage, ligaments and bone marrow into absorbable biological compounds — among them collagen, which breaks down into gelatin, glycosaminoglycans, amino acids and trace minerals.

A food forgotten in the era of processed food, bone broth has returned to the forefront of clinical research in recent years, as researchers seek to understand why traditional cuisines in every culture kept it as a home remedy.

Main nutritional composition

A cup (240 ml) of good-quality homemade bone broth typically contains:

• About 40–50 calories
• 9–10 grams of protein (mainly gelatin)
• 0.5–1 gram of fat
• Minerals: calcium, magnesium, phosphorus, potassium and silica
• Glycosaminoglycans: glucosamine, chondroitin, hyaluronic acid
• Amino acids: glycine, proline, hydroxyproline, glutamine

Research-based health benefits

• Collagen and gelatin for joint health: During long cooking, collagen (the main structural protein in cartilage and connective tissue) breaks down into gelatin — an absorbable protein. Gelatin supplies procollagen for the synthesis of new collagen in the body’s tissues. Clinical studies have shown that consuming collagen products (including gelatin from bone broth) can reduce joint pain and improve flexibility in people with osteoarthritis.

• Glycine — a multi-purpose amino acid: Bone broth is one of the best natural sources of glycine. This amino acid, which most people do not get enough of on a modern diet, is involved in collagen synthesis, in producing glutathione (the body’s main internal antioxidant), in producing bile salts (for fat digestion), in brain function — it also acts as an inhibitory neurotransmitter and as a co-agonist of NMDA receptors — and in improving sleep quality.

• Gut healing: Glutamine (another amino acid abundant in bone broth) is the preferred fuel of the epithelial cells of the small intestine. Studies have shown that glutamine helps improve the integrity of the gut barrier and may contribute to treating “leaky gut” (intestinal permeability) — a condition linked to inflammatory diseases, allergies and irritable bowel syndrome.

• Hyaluronic acid for skin and joints: Hyaluronic acid (HA) is a molecule well known in the cosmetics industry, but when taken internally it may help maintain skin hydration, joint flexibility and proper function of the synovial fluid (joint fluid). Bone broth provides HA in small but bioavailable amounts.

• Biological minerals from bones: Bones contain calcium, magnesium and phosphorus. Adding vinegar to the cooking (even if the final broth does not taste sour) helps release these minerals from the bone matrix into the cooking liquid. The amount of minerals depends on the type and quality of the bones.

• Bone marrow — a unique concentration of fats: Bone marrow is an especially rich tissue — it contains fats, vitamin B12, vitamin K2, zinc and alkylglycerols (fats being studied in the context of immune support). When bones with marrow are cooked, these nutrients are released into the broth.

• Calming effect and better sleep: Specific studies on glycine alone showed that taking 3 grams of glycine before bed improved sleep quality, reduced morning sleepiness and improved cognitive performance. A 240 ml serving of bone broth may provide 1–2 grams of glycine — that is, one third to two thirds of the dose tested in the studies.

Downsides and health considerations

• Limited direct scientific evidence for bone broth: Most clinical studies focus on specific components (collagen, glutamine, glycine) and not on bone broth as a whole. It is hard to control the concentrations of components in homemade broth, which vary with the type of bones, cooking time and handling.

• Lead and heavy metals: A study published in Medical Hypotheses (2013) tested lead levels in chicken bone broths and found low but measurable amounts, higher than those in tap water. Bones tend to accumulate heavy metals over the animal’s lifetime, so bones from animals raised in a polluted environment may contain higher concentrations. This particular study is controversial and has methodological limitations.

• High sodium in commercial versions: Commercial bone broths, and especially packaged liquid stocks, are often loaded with sodium (500–900 mg per 240 ml). Making it at home allows you to control the amount of salt.

• Histamine with long cooking: Long cooking raises the concentration of histamine — a biogenic amine formed from the breakdown of the amino acid histidine, partly through bacterial action. People with histamine intolerance (MCAS, DAO enzyme deficiency) may experience reactions such as headache, rash or nausea after drinking bone broth.

• Oxidation of unsaturated fats: Long cooking at high heat may oxidize unsaturated fats (PUFA). It is recommended to cook on low heat (85–95°C, 185–203°F) and store the broth properly (fridge up to 5 days, freezer up to 3 months).

How to make good-quality bone broth

1. Choosing bones: Marrow bones, oxtail, wings with bones and chicken feet are the best choices for concentrated gelatin and minerals.
2. The roasting stage: Roasting the bones in the oven at 200°C (392°F) for 30–40 minutes before cooking improves flavor and creates Maillard reactions that add depth.
3. Adding vinegar: One or two teaspoons of natural apple cider vinegar before you start cooking helps release minerals from the bones.
4. Cooking time: 12–24 hours for beef bones, 8–12 for chicken, 4–6 for fish. A broth that sets into a jelly when chilled — that is a sign of a good gelatin concentration.
5. Straining: Strain well through a fine sieve before serving.

Summary

Bone broth is a traditional, high-value food that provides gelatin, glycine, glutamine, hyaluronic acid and minerals in a biological form. Although the direct clinical evidence on it as a whole product is still limited, the individual components it provides have been studied extensively and point to benefits for the joints, the gut lining and sleep. Careful homemade preparation, control over the quality of the bones and cooking at a low temperature — these are the key to getting the most out of this broth.