Bone broth and collagen have gained popularity due to their numerous health benefits, particularly in the context of gut healing, joint health, and skin improvement. However, recent concerns have emerged regarding the presence of toxic heavy metals, such as arsenic, cadmium, chromium, lead, and mercury, in these products. This report reviews the research surrounding heavy metals in bone broth and collagen supplements, their potential health risks, the types of damage they can cause to the human body, and key findings from recent studies. 

Heavy Metals in Collagen and Bone Broth 

Heavy metals like arsenic, cadmium, lead, and mercury are naturally present in the environment. Farm animals can be exposed to these contaminants through their food, water, soil, and air, which leads to the accumulation of heavy metals in their bones. When these bones are used to prepare broth or collagen supplements, heavy metals can leach into the final product. 

Lead Contamination in Bone Broth 

A notable study published in the journal Medical Hypotheses titled "The risk of lead contamination in bone broth diets" raised concerns about the potential lead content in bone broth. The authors indicated that lead, a known neurotoxin, can accumulate in the bones of animals due to environmental exposure. The study found that bone broth, especially when simmered for extended periods, could release significant amounts of lead into the broth. The researchers cited that lead exposure through food could lead to deficits in growth, cognitive impairments, and other health issues, particularly in children and vulnerable populations. 

Another study examined the lead content in bone broth made from chicken bones and found that the broth contained over ten times more lead than the water used to prepare it . This finding suggests that prolonged boiling of animal bones may release stored lead into the broth, posing a potential risk to consumers who regularly incorporate bone broth into their diets. 

Arsenic, Cadmium, and Other Metals in Collagen Supplements 

In addition to lead, collagen supplements have been tested for other heavy metals. According to a recent study, 64% of the collagen products tested had detectable levels of arsenic, ranging from 0.09 micrograms to 4.7 micrograms per serving. While none of the products exceeded the 10 micrograms/serving threshold set by the State of California, the presence of arsenic still raises concerns, as chronic exposure to arsenic has been linked to various health issues, including skin lesions, cardiovascular disease, and cancer . 

Cadmium, another toxic metal, was found in 17% of the collagen products tested. Cadmium is known to cause kidney damage and bone demineralization when consumed in excessive amounts. One collagen Bullet proof product,  Collagen Protein Chocolate, had over twice the California Prop 65 threshold for cadmium. 

Lead was also detected in 37% of the collagen products, with the highest concentration found in Orgain Collagen Peptides, Unflavored. A single serving of this product contained over three times the California threshold for lead, further illustrating the risk of heavy metal exposure through collagen supplements. 

Health Effects of Heavy Metals 

Heavy metals, even in trace amounts, can cause significant damage to the body, particularly when exposure is chronic. The nervous system, kidneys, bones, and overall health can be affected, with long-term consequences for physical and mental well-being. 

Lead 

Lead is a well-known neurotoxin that primarily affects the nervous system, causing both immediate and long-term damage. Chronic lead exposure can lead to a wide range of health issues: 

• Nervous system damage: Lead exposure is particularly dangerous for children, as it can impair cognitive development, reduce IQ, cause learning disabilities, and result in behavioral issues like attention deficits and hyperactivity . In adults, chronic lead exposure can result in neuropathy, which causes weakness, numbness, and pain, usually in the hands and feet. 

• Cardiovascular system: Lead exposure can contribute to hypertension (high blood pressure) and increase the risk of cardiovascular diseases. 

• Kidneys: Chronic exposure to lead can lead to kidney damage and reduced kidney function over time. 

• Bone health: Lead competes with calcium in the bones, potentially weakening bone density and increasing the risk of osteoporosis . 

• Reproductive health: Lead has been shown to affect reproductive health in both men and women, potentially leading to reduced fertility and complications during pregnancy. 

Arsenic 

Arsenic exposure is primarily associated with contamination of drinking water, but it can also enter the body through food products such as bone broth and collagen. The health effects of arsenic include: 

• Carcinogenic effects: Long-term arsenic exposure is linked to an increased risk of cancers, particularly skin, bladder, lung, and kidney cancer. 

• Skin damage: Arsenic can cause skin changes, including lesions, hyperpigmentation, and thickened skin patches (keratosis). 

• Cardiovascular system: Chronic arsenic exposure is associated with an increased risk of heart disease and stroke. 

• Endocrine disruption: Arsenic exposure can interfere with hormone regulation, potentially leading to diabetes and other endocrine disorders . 

Cadmium 

Cadmium is another toxic metal commonly found in industrial pollutants, but it can also enter the body through contaminated food and supplements. The health effects of cadmium include: 

• Kidney damage: Cadmium is known to accumulate in the kidneys, leading to progressive kidney damage and the loss of kidney function . 

• Bone demineralization: Chronic cadmium exposure can interfere with calcium metabolism, resulting in weakened bones and an increased risk of fractures. This condition is known as osteomalacia in adults. 

• Lung damage: Inhalation of cadmium, especially in industrial settings, has been linked to lung cancer and other respiratory diseases . 

Mercury 

Mercury is a highly toxic metal that can cause severe damage to the nervous system and other organs: 

• Nervous system damage: Mercury primarily affects the brain and nervous system, leading to symptoms such as tremors, memory problems, and difficulties with concentration. High levels of mercury can cause irreversible damage to the central nervous system. 

• Kidney damage: Like cadmium, mercury can accumulate in the kidneys, leading to kidney dysfunction over time. 

• Developmental effects: Pregnant women exposed to mercury may experience complications, and the fetus can be at risk of neurological development issues . 

Study Findings and Methodology 

In a small-scale study conducted by Dr. Kara Fitzgerald and her team, three beef bone broth samples and one hydrolyzed beef collagen powder were analyzed for the presence of 37 toxic and essential minerals and metals. The samples were tested using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), which is capable of detecting metal concentrations as low as 0.001 parts per million (ppm). This method is more sensitive than standard industry testing, allowing for a detailed assessment of metal contamination in bone broth and collagen . 

The study's findings confirmed that bone broth and collagen could contain trace amounts of heavy metals, including lead, arsenic, cadmium, and aluminum. However, the amounts detected were generally low and within safety thresholds set by regulatory authorities like the State of California. The report emphasized that while these levels might not pose an immediate risk, they could contribute to cumulative heavy metal exposure in individuals who frequently consume these products . 

Conclusion 

Bone broth and collagen are widely regarded for their health benefits, but recent research highlights the need for caution regarding heavy metal contamination. The levels of arsenic, cadmium, lead, and mercury detected in most products are below harmful thresholds, but consumers should be aware of the potential risks of long-term exposure, especially for vulnerable populations. Further research and more stringent industry testing standards are necessary to ensure the safety of these popular health supplements. 

Warm regards,  
Diana Stobo

Footnotes 

1. Medical Hypotheses. “The risk of lead contamination in bone broth diets.” 

1. Dr. Kara Fitzgerald, ND. “Bone Broth Report: Investigating for Lead and Toxic Minerals PLUS Nutritional Value.” 

1. State of California Environmental Protection Agency, Proposition 65. 

1. Fitzgerald, K. (ND). "Bone Broth Report." 

1. Medical Hypotheses. "Lead contamination in bone broth diets." 

1. US Environmental Protection Agency. "Lead Poisoning and Health Risks." 

1. National Institutes of Health. "Lead Exposure and Mental Health in Adults." 

1. Fitzgerald, K. (ND). "Arsenic and Heavy Metal Contamination in Collagen Supplements." 

1. Fitzgerald, K. "Bone Broth Report: Analysis and Findings."