Supplemental colloidal gold exists as a sol or dispersal of gold nanoparticles in water. A colloid is simply a mixture of two substances in which the dispersed particles will not settle out. Nanoparticles are tiny, and typically have a diameter of somewhere between one and one hundred nanometers – a nanometer being one billionth of a meter. Gold colloids were first synthesized as early as the fifth century BCE and have a surprisingly long history of medicinal application [1]. For example, the therapeutic value of gold in general was supported by the Greek physician Hippocrates, the Swiss alchemist Paracelsus, and the English herbalist Nicholas Culpeper [2]. Gold is a noble metal and is normally quite unreactive or chemically inert, but gold nanoparticles can behave differently than bulk gold [3]. Gold nanoparticles scatter visible and near infrared light, so the color of gold colloids can vary [4]. In addition to the spherical geometry of gold colloid particles, various geometries in the form of nanorods, nanoshells, nanocages, and nanostars are also currently in use in the world of nanogold [5].
Gold nanoparticles have shown promise as gene therapy vehicles, being able to readily enter cells and silence particular genes by carrying small interfering RNAs to nuclei [6]. And since the uptake of gold nanoparticles by tumor cells is greater than that of normal, healthy cells, gold nanoparticles can somewhat selectively deliver anticancer agents to tumorous regions [7]. Gold nanoparticles can prevent tumors from growing by blocking angiogenesis too [8]. Impressively selective thermal ablation of diseased or infected tissue can also be accomplished with the use of gold nanoparticles because of their efficient capacity to convert absorbed light into heat [9]. Because of this ability, I personally contend that colloidal gold supplementation could extend or amplify the beneficial effects of infrared sauna therapy. Furthermore, gold nanoparticles can be conjugated with antibodies or antimicrobials and then serve as photothermal agents in selectively attacking particular bacteria and protozoa [10]. It seems that the distribution of gold nanoparticles around the body is dependent upon their size, with smaller particle sizes showing a more widespread distribution [11]. Temporary accumulation appears to be greatest in the liver, spleen, and lungs, and gold nanoparticles with a size of 50 nanometers or less may be capable of crossing the blood-brain barrier [12]. Gold nanoparticles with a diameter of less than 5.5 nanometers appear to be excreted from the body largely through the kidneys, but evidence suggests that larger particles are cleared by the mononuclear phagocyte arm of the immune system and then ultimately excreted through the gut by way of the hepatobiliary system [13] [14]. This would account for the observed accumulation of gold nanoparticles in the liver and spleen. Dykman and Khlebtsov allege that it takes about 3 to 4 months for all accumulated gold nanoparticles to be excreted from the liver and spleen, but this timescale would depend upon the size of the particles, the dosage used, and the congestion of the liver and spleen [15]. The absorption of orally administered gold nanoparticles occurs in the small intestine [16]. Gold nanoparticles with a very small size (less than 2 nanometers) can be very detrimental and can induce mitochondrial damage and tissue necrosis via oxidative stress [17]. Conflicting research exists, but the general consensus is that gold nanoparticles with a diameter of roughly 5 nanometers or greater (up to around 100 nm) in spherical colloid form are nontoxic and safe at reasonable dosages [18] [19]. And at least some reported instances of toxicity may be due not to the gold nanoparticles themselves, but to surfactants or capping agents, as well as various impurities [20]. The findings of Shukla et al. suggest that gold nanoparticles of the appropriate size are not cytotoxic and do not induce production of the proinflammatory cytokines tumor necrosis factor-alpha and interleukin-1 beta, and actually lower the making of some free radicals [21]. But again, evidence contrary to the complete safety of gold nanoparticles has been documented, so at least be wary in your purchasing of colloidal gold supplements [22]. Outside of medicine, gold nanoparticles (AuNPs) have a large range of applications in the fields of physics, chemistry, and biology, but in this article I’m going to focus on the potential benefits that may be derived from supplemental colloidal gold in its common form [23]. In a study conducted in 2007, colloidal gold administered subcutaneously inhibited the development of three forms of experimental arthritis (Mycobacterium tuberculosis-, collagen-, and pristane-induced arthritis), and the effect lasted long after treatment ceased [24]. Similar results were seen in a study where colloidal gold was injected intraarticularly into rats with collagen-induced arthritis [25]. In another study involving colloidal gold given orally to ten rheumatoid arthritis patients, nine of the patients experienced marked improvement after about five and a half months using a dosage of 30 mg/day, with three patients achieving clinical remission [26]. Interleukin-6, tumor necrosis factor-alpha, and rheumatoid factor reportedly decreased in each of the subjects. Interestingly, Abraham et al. observed a 20% increase in mean IQ scores in subjects administered colloidal gold orally for a period of one month [27]. In some of the subjects, the IQ boosting effect lasted for up to two months after discontinuation of the supplement. In a 1936 paper published in the journal Archives of Dermatology and Syphilology, the giving of colloidal gold to a single patient with lupus offered “encouraging results,” but no mechanism of action was determined [28]. Colloidal gold has also exhibited antibacterial action against the species Escherichia coli, Vibrio cholerae, Salmonella typhimurium, and Shigella dysenteriae [29]. Gold nanoparticles have also demonstrated antifungal activity against different Candida species [30]. In another interesting study, gold nanoparticles with a diameter of 21 nanometers were injected into mice through a single dose, resulting in a significant loss of fat mass without a concomitant significant decrease in total body weight (after 72 hours) [31]. The fat loss induction was apparently due to a reduction in adipose tissue macrophage activity, which we know can boost lipolysis in fat cells [32]. Something intriguing is the fact that so-called naturally-occurring gold has been found in human glandular and reproductive tissues, and in women, the concentration of this gold fluctuates with the menstrual cycle [33]. In men, Skandhan and Abraham have claimed that gold measured in normal semen is the “richest source of gold reported in biological materials” [34]. Accordingly, it has been suggested that gold may have a physiological function [35]. During the first half of the previous century, quite a few papers were published on the use of colloidal gold with arthritis patients, but that research began to taper off during the 1950s [36] [37]. At least to a degree, the “tomato effect” seems to have been operant in the medicinal employment of gold during the last few decades [38]. A wide array of claims have been made regarding the benefits of colloidal gold supplementation, but outside of the potential benefits listed in this article, to my knowledge those claims have not been empirically substantiated (and might I add that my review of the research literature was very extensive). An exception to that statement could be the Ayurvedic medicament Swarna bhasma, which when prepared correctly should contain at least some colloidal gold. Though safety concerns over impurities that can be present in the formulation have been raised [39]. In conclusion, very pure colloidal gold supplements containing no additives and made with distilled water, housing spherical nanoparticles with a diameter of more than 5 nanometers, are probably safe at reasonable dosages. Those with some form of arthritis are probably the most likely to see some kind of avail from colloidal gold’s use. But I would be very choosy in evaluating manufacturers of colloidal gold supplements as there are a lot of gold products out there that are either completely useless or downright dangerous. References:
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AuthorDenton Coleman is an Exercise Physiologist and Medical Researcher. Archives
October 2023
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