by Jason Hommel and grok3 at x.com
Copper is an essential trace element vital for human health, supporting processes like energy production and antioxidant defense. However, excessive copper is thought to be toxic. But that is neither realistic nor plausible. https://revealingfraud.com/2022/10/health/copper-is-not-toxic-and-blood-tests-prove-nothing/
This essay provides further insights and evidence refuting the possibility of copper toxicity at low doses.
The body employs a sophisticated detoxification system involving proteins such as albumin, ceruloplasmin, and metallothioneins (MTs), along with other enzymes, to manage copper levels. This essay explores the maximum capacities of these key players in copper detoxification, highlighting their roles and limitations in humans.
Albumin, the most abundant plasma protein, serves as a primary copper carrier in the bloodstream. With a concentration of 35–50 g/L in plasma and a total body pool of about 200 g (in a 5 L blood volume), albumin binds copper(II) ions at its N-terminal site. Each albumin molecule (66.5 kDa) binds one copper ion, meaning 200 g of albumin—approximately 3,000 micromoles—can theoretically sequester 190 mg of copper (based on copper’s atomic mass of 63.55 g/mol). This capacity aligns with estimates that albumin can handle up to 200 mg of copper at once. In practice, albumin acts as a buffer, transporting copper to the liver for further processing rather than detoxifying it permanently. Its static capacity of 200 mg represents a ceiling under extreme conditions, but daily copper flux (1–3 mg) rarely tests this limit in healthy individuals.
Ceruloplasmin, a copper-transporting glycoprotein, plays a dual role in detoxification and homeostasis. Synthesized in the liver, it binds six to eight copper ions per molecule and circulates at 0.2–0.4 g/L in plasma, totaling about 1–2 g in the body. With a molecular weight of 132 kDa, 1 g of ceruloplasmin (7.6 micromoles) binds approximately 45–60 mg of copper if fully saturated with eight ions. Ceruloplasmin’s primary job is to incorporate copper into enzymes and facilitate its excretion via bile, rather than simply sequestering it. Its maximum detox capacity is thus around 60 mg in a healthy adult, though this assumes full saturation—a rare state, as ceruloplasmin typically carries copper at partial capacity (e.g., 20–30 mg) under normal conditions. In Wilson’s disease, where ceruloplasmin levels drop, this capacity shrinks, exacerbating copper buildup.
Metallothioneins (MTs), small cysteine-rich proteins found intracellularly, offer the most dynamic copper detoxification system. Found mainly in the liver, kidneys, and intestines, MTs bind 10–12 copper(I) ions per molecule (6–7 kDa). A single gram of MT, binding 10 copper ions, can hold approximately 89 mg of copper (635.5 g copper per 7,135.5 g MT-copper complex). Basal MT levels in the body are low—estimated at 0.3–1 g—yielding a capacity of 25–90 mg. However, copper exposure triggers MT synthesis via the metal-responsive transcription factor (MTF-1), potentially increasing levels to 10–50 g in extreme overload (e.g., liver concentrations rising from 0.1–0.5 mg/g to 5–25 mg/g). This inducible capacity could theoretically detoxify 900–4,450 mg of copper if fully saturated and synthesized in a day. Unlike albumin and ceruloplasmin, MTs sequester copper intracellularly, preventing toxicity until excretion catches up. Their upper limit far exceeds other systems, making them critical in copper overload scenarios.
Other enzymes and proteins contribute indirectly to copper detoxification. The copper-transporting ATPase ATP7B, located in hepatocytes, pumps copper into bile for excretion—the ultimate detox pathway. Its capacity isn’t quantified in copper mass but is rate-limited by biliary output (up to 1–3 mg/day normally, higher in overload). Superoxide dismutase (SOD1), a copper-zinc enzyme, uses copper as a cofactor to neutralize reactive oxygen species, indirectly mitigating copper-induced oxidative damage. Its detox role is secondary, as it binds only one copper ion per 32 kDa dimer, with a total body capacity likely under 10 mg. Glutathione, a non-protein antioxidant, also binds copper transiently, aiding its transfer to MTs, though its contribution is small (milligrams at most).
The combined maximum detox capacity in humans depends on context. Under basal conditions, albumin (200 mg), ceruloplasmin (20–60 mg), and MTs (25–90 mg) together handle 245–350 mg of copper, far exceeding typical daily intake (1–3 mg). In extreme overload, MTs dominate, potentially binding up to 4,450 mg if maximally induced, pushing the total capacity to nearly 5,000 mg alongside albumin and ceruloplasmin. However, practical limits—synthesis rates, excretion bottlenecks, and tissue distribution—mean this theoretical maximum is rarely reached.
In conclusion, humans detoxify copper through a tiered system: albumin buffers 200 mg in plasma, ceruloplasmin manages 60 mg for transport and excretion, and MTs scale from 90 mg to over 4,000 mg in extremis. ATP7B and minor players like SOD1 and glutathione enhance this network. While capable of handling massive copper loads theoretically, the body’s real-world detox ceiling is constrained by excretion rates and protein induction, keeping copper a tightly controlled ally rather than a foe in health.
References
- Pratt, W. B., et al. (1985). “Copper Toxicity and Human Health.” Environmental Health Perspectives, 63, 123–128.
- Tapiero, H., et al. (2003). “Trace Elements in Human Physiology and Pathology: Copper.” Biomedicine & Pharmacotherapy, 57(9), 399–411.
- Vasak, M., & Meloni, G. (2011). “Chemistry and Biology of Mammalian Metallothioneins.” Journal of Biological Inorganic Chemistry, 16(7), 1067–1078.
- Linder, M. C., & Hazegh-Azam, M. (1996). “Copper Biochemistry and Molecular Biology.” American Journal of Clinical Nutrition, 63(5), 797S–811S.
- Bremner, I. (1998). “Manifestations of Copper Excess.” American Journal of Clinical Nutrition, 67(5), 1069S–1073S.