Colloidal silver

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Colloidal silver is a colloid of silver particles in water. It has antimicrobial properties and was, in the past, used on external wounds and burns to prevent infection. Some alternative-health practitioners claim that it is a beneficial nutritional supplement. Others also claim that it is a powerful antibiotic[1] which is relatively safe for human consumption, though this is disputed because of the risk of argyria,[2] a permanent blue or gray skin condition which is otherwise benign. The intake of some silver products in large quantities over long periods of time has caused argyria in some people,[3][4][5][6] though at dosage levels generally considered normal, the risk for argyria is low. Agyria and the development of abnormal hepatic function, dilated cardiomyopathy, amnesia and incoherent speech have recently been reported in association with taking colloidal silver over several months.[2]

Contents

[edit] Applications

Colloidal silver can be used to keep drinkable water potable over a long period.[1] Silver has been used as a topical antiseptic for minor burns for more than 100 years.[7] Concentrations of colloidal silver at 5 parts per million or higher have been found to kill numerous infectious bacteria.[8]

Colloidal silver is also used in some thermal greases, due to silver's high thermal conductivity.

[edit] Controversies

[edit] Argyria

Long-term intake of high doses of certain silver products may result in argyria, a rare condition of blue or gray discoloration of the skin.[3][4][5] While generally considered permanent, some have claimed to have reversed it.[9] Argyria is non-fatal[10] and has no other known negative health implications.[11] Almost all known cases of argyria resulted from exposure to or use of silver compounds, such as silver oxide, silver nitrate, and silver chloride.[citation needed] Even the well-known case of Stan Jones, a Montana Libertarian candidate for the U.S. Senate in 2002 and 2006, was found, after a scrutiny of his production methods, to have likely been caused by silver chloride and/or other silver compounds. This was due to (1) his use of mineral-rich well water, (2) his adding of salt as an accelerant, (3) his unusually long production times, and (4) his failure to filter the final product.[12] Mr. Jones began producing and ingesting his silver product in 1999, due to fears of antibiotics being unavailable due to "Y2K" bug problems.[6] Advocates assert that, under careful use of properly produced colloidal silver, argyria is virtually impossible,[13] though these claims are anecdotal and have not been confirmed by scientific study.[attribution needed]

[edit] As a supplement

Advocates of colloidal silver claim it to be a useful supplement to their diet, providing them with improved health and well being and (among other things) a low incidence of colds and flu.[citation needed] These claims are not supported by scientific study and are not accepted by the mainstream medical community.

[edit] Corporate changes

Though colloidal silver was once produced by pharmaceutical companies under various names including Protargol, it gradually fell into disfavor, with the development of sulfa drugs in the 1930s and the development of penicillin in the 1940s. By the mid 1970s, all major U.S. pharmaceutical companies had ceased production of colloidal silver.[14]

[edit] Government reactions

The U.S. Food and Drug Administration (FDA) banned over-the-counter sales in the U.S. of any product claiming to have therapeutic value, health benefits, or making any medical claims, unless it is a drug. Despite colloidal silver's earlier history as a drug, the product now has the status of a dietary supplement in the US (dietary supplements cannot claim to cure diseases, only that they "support healthy functioning").[15][16] The FDA has issued warnings to Internet sites selling or promoting colloidal silver as an antibiotic or for other medical purposes.[17] If no medical benefits are claimed, colloidal silver is sold as a supplement, and as long as the products comply with all other FDA regulations, its sale is considered legal. In 2002, the Australian Therapeutic Goods Administration made a similar ruling.[18]

[edit] Terminology

The term, "colloidal silver", has been used inaccurately by some to advertise products which are mostly silver compounds or proteins bound with silver[citation needed]. This has contributed to over-all confusion about the term, "colloidal silver", in the market. In order for a mixture to be a true silver colloid, the silver atoms must be tiny metallic particles suspended in solution.

[edit] Differing preparations

Confusion around colloidal silver is increased by the fact that there is more than one manufacturing process, and that these lead to a number of significantly different products, all of which go by the name "colloidal silver", and which have differing properties.

Preparations called 'colloidal silver' include:

  • Electrolytic silver (most common method used today)
  • Ground silver (standard form of colloidal silver pre-World War II)
  • Electrolysis of salt solution (produces a yellow product)

[edit] References

  1. ^ a b Silvermedicine.org: Benefits of Colloidal Silver
  2. ^ Fung MC, Bowen DL. Silver products for medical indications: risk-benefit assessment. Journal of Toxicology and Clinical Toxicology 34:119-26, 1996. available online
  3. ^ a b U.S. Environmental Protection Agency (2003). Silver. Retrieved on 2006-08-05.
  4. ^ a b Hill, W. R.; Pillsbury, D. M. (1939). Argyria: The pharmacology of silver. Baltimore, MD: Williams & Wilkins Co., 131. 
  5. ^ a b Gaul, L. E.; Staud, A.H. (1935). "Seventy cases of generalized argyria following organic and colloidal silver medication, including biospectrometric analysis of ten cases". AMA 104: 1387-1390. 
  6. ^ a b True-blue bids for Senate, 2002-10-03, BBC
  7. ^ Complementary Medicine - Information about complementary & alternative medical therapies, Cedars-Sinai Health System
  8. ^ BYU Study
  9. ^ Argyria-Reversal Claim
  10. ^ ATSDR-ToxFAQs: Silver
  11. ^ "Joshua B Glenn, Anna N Walker: Argyria In An Elderly Man. The Internet Journal of Dermatology. 2002. Volume 1 Number 2 available online
  12. ^ Stan Jones letter
  13. ^ Silvermedicine.org: Argyria - Colloidal Silver Safety.
  14. ^ (1996) Silver Solutions. Tampa, FL: GHI/MRI, 3. 
  15. ^ COLLOIDAL SILVER NOT APPROVED FDA reports "Use of colloidal silver ingredients in food-producing animals constitutes a potentially serious public health concern", Wednesday, February 12, 1997
  16. ^ FDA ISSUES FINAL RULE ON OTC DRUG PRODUCTS CONTAINING COLLOIDAL SILVER FDA, 1999-08-17
  17. ^ FDA warning healthymagnets
  18. ^ TGA. Regulation of colloidal silver and related products Therapeutic Goods (Excluded Goods) Order No. 1 of 2005 [1] revoked Therapeutic Goods (Excluded Goods) Order No. 1 of 2004. 9 November 2005 update

[edit] See also

[edit] External links

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