Jayant Radhakrishnan
Chicago, Illinois, United States
According to the Merriam-Webster Dictionary, “snake oil” is a noun that refers to “any of various substances or mixtures sold (as by a traveling medicine show) as medicine usually without regard to their medical worth or properties.” They also call it “poppycock, bunkum.”1 “Snake oil salesman” originated as a pejorative term for a person who swindles people by selling them fake medical cures. Early in the twentieth century, the term took on an even wider scope after it was used by Stephen Vincent Benét in Book Eight of his poem “John Brown’s Body” about the American Civil War. In the aftermath of the war, he speaks of “crooked creatures of a thousand different trades…. Sellers of snake oil balm and lucky rings.” Some years later, Eugene O’Neill used the term in Act One of The Iceman Cometh when Mosher claims that a great physician once told him that “rattlesnake oil, rubbed on the prat, would cure heart failure in three days.” Later, referring to the dead physician, he said, “I’ll bet he’s standing on a street corner in hell right now, making suckers of the damned, telling them there’s nothing like snake oil for a bad burn.” Since then, the term has been applied to anyone who is believed to be exploiting the unsuspecting with false promises. Politicians have even used it to disparage their opponents.
For some unknown reason, snake oil has been endowed with a wide array of healing powers for about three centuries. An eighteenth-century European recipe for making the viper oil of Mesues is as follows: “Take 2 pounds of live snakes and 2 pounds 3 ounces of sesame oil. Cook slowly, covered in a glazed pot, until meat pulls away from the bone. Strain and store. Uses: Cleans the skin, removes pimples, impetigo, and other defects.”2 In the United States, however, there is a different, unconfirmed narrative for how snake oil became a treatment for ailments. Between 1862 and 1869, approximately 14,000 Chinese indentured laborers worked on the western part of the transcontinental railroad, although photographs at its completion only show those of European heritage. While the Chinese earned between half to two-thirds of what white European immigrants were paid, they worked in dangerous and appalling conditions all day, every day throughout the year.3 According to unsourced tales, they brought with them oil of the Chinese water snake, a topical application for the inevitable aches, pains, cuts, and bruises that resulted from their job. Supposedly, they shared it with other railroad laborers who found it very beneficial. Its use spread from the laborers to the population at large. This caught the attention of entrepreneurs who did not have access to the Chinese water snake. They decided to use rattlesnakes instead, and the more unscrupulous even went so far as to peddle mineral oil without a trace of snake oil in their liniments. The most notorious of these was Clark Stanley, “The Rattlesnake King.” In 1916, the United States Bureau of Chemistry sued him, finding that his Snake Oil Liniment contained only light mineral oil, 1% fatty oil (probably beef fat), capsaicin, and possibly a trace of turpentine and camphor. He pleaded nolo contendere and was fined $20.4 Following this case, the remedy lost its popularity. Incidentally, Stanley claimed that he learned about the properties of rattlesnake oil from a Hopi medicine man and not the Chinese.
Polyunsaturated fatty acids (PUFAs) such as omega-3 and omega-6 are classified as essential fatty acids because the human body does not synthesize an adequate amount for survival. They have to be obtained from food. Omega-3 fatty acids consist of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), both of which are found only in fatty fish and edible algae. The third omega-3 is alpha-linolenic acid (ALA), which can be obtained from plants. Very little ALA is converted into EPA.
In 1985, researchers augmented the diet of seven normal subjects for six weeks with 3.2g of EPA and 2.2g of DHA. From the study they postulated that “diets enriched with fish-oil-derived fatty acids may have anti-inflammatory effects by inhibiting the 5-lipoxygenase pathway in neutrophils and monocytes and inhibiting the leukotriene B4 mediated functions of neutrophils.”5 Four years later, a psychiatrist who was a proponent of nutrition-based medicine and a co-founder of the Orthomolecular Medical Society had Chinese water snake (Enhydris chinensis) oil analyzed. He reported that it contained 19.6% EPA, while levels of DHA (0.001%) and ALA (0.001%) were very low. In contrast, the fat of one black and one red rattlesnake he sent for analysis had negligible amounts of all omega-3 fatty acids. He went a step further and opined that essential fatty acids are absorbed through the skin; therefore, inflamed skin and joints could benefit from local application of Chinese snake oil.6 His ideas were ignored until the lay press resurrected them in this century.7,8
EPA is an essential part of the cell membrane and an aid to intercellular interactions. Therefore, it is a vital ingredient for normal function of all body systems. While omega-3 fatty acids may potentially influence many systems, in this article we are concerned only with the effects of EPA on the musculoskeletal system and its ability to reduce inflammation. To consider it a legitimate therapeutic option, the following fundamental questions have to be answered. First, does EPA reduce aches and pains from bones, joints, and muscles, and thereby improve function? Secondly, does supplemental EPA in a person with normal omega-3 levels enhance that beneficial effect? Finally, can EPA derived from snake oil be absorbed through the human skin in sufficient quantities to be therapeutic?
Eccentric muscle exercise studies on healthy adult volunteers who received oral omega-3 fatty acids derived from fish oils have demonstrated reduction in muscle soreness and inflammation, along with better maximal voluntary contraction and range of motion in the treated group when compared to the placebo group. Laboratory tests also indicated reduced muscle damage in the treated group.9,10,11,12 Recorded muscle soreness in treated subjects yielded ambiguous results. Unfortunately, the studies were not comparable across the board since in some studies volunteers were subjected to a pre-study period of omega-3 deprivation, while that was not the case in other studies. In addition, the dose ingested, duration of administration, study design, and the joint exercised varied. Omega-3 fatty acids have also been shown to reduce inflammation and improve joint function in patients with osteoarthritis13,14 and rheumatoid arthritis.15,16
It should be noted that the oral fish oil administered to these subjects contained both EPA and DHA, whereas the sample of Chinese water snake oil evaluated only contained EPA.6 Only some studies determined the plasma concentrations of EPA and DHA before and after supplementation. The plasma DHA levels are important because it also has anti-inflammatory actions that would augment the action of EPA.17,18 Therefore, to answer the first question, there is evidence that oral EPA reduces pain and improves function when intake of omega-3s is restricted before the study. However, no study has investigated whether supplemental EPA in people with presumably normal levels, as would be the case in healthy, fish-eating Chinese laborers, would further enhance the benefits. It is also not known how much DHA contributed to the beneficial effects noted in the studies.
Since vertebrates do not synthesize PUFAs, it is assumed that these water snakes derive their PUFAs by eating fish and amphibians which, in turn, derive it from algae. Saltwater fish have more PUFAs than freshwater fish and there is a geographic variation in the concentration of PUFAs in fish. In addition, the type of fish, its environment, habitat, season when harvested, and its age all alter the concentration of PUFAS.19 It follows that snakes that devour these fish, and so their oil might also have varying levels of PUFAs which would not necessarily be reflected in the evaluation of just one sample obtained in San Francisco.6 The oil from different regions and from different species of water snakes would have to be analyzed to determine the norm. To make the oil, the body fat of the snake is removed and rendered (heated) to separate oil from other tissues. The oil derived is collected and purified. The formulation of the EPA in the oil has not been determined.
The intact epidermis, particularly the stratum corneum, is a near perfect barrier to the absorption of substances into the body. For transdermal passage, the molecular mass of the fat must be less than 1 kilodalton (kDa) (preferably <500 Da), it must be lipophilic (log Po/w ≅ 1-3), have a low melting point (<200°C), and be slightly acidic (pH 4.6–5.5). EPA is liquid at room temperature, it is lipophilic, and its molecular mass is 302.45 Da, but it is subject to oxidation and its physical properties can be influenced by temperature, pressure, and the presence of other substances. The rate and amount absorbed is also modified by the area on which it is applied, thickness of the epidermis at that location, duration of contact, application of an occlusive cover, the temperature, formulation of the product, concentration of the EPA in it, presence of additional compounds and other factors.20 The fact is that even when extraordinary maneuvers are employed, the amount of EPA that actually makes its way through the skin is minimal.21
To date, no one has studied the rate of absorption of Chinese water snake oil from the skin with or without the help of ancillary measures to enhance absorption through the dermis and into the vasculature. Finally, no studies have demonstrated therapeutic effects of this oil applied as a liniment. PUFAs essentially stay in the skin and may be of help in treating skin inflammation. In other words, reliable data regarding internal benefits of topically applied PUFAs is non-existent, and to conflate data from oral intake of EPA and DHA is a questionable maneuver. Because of the lack of information, one cannot categorically discount the claim that EPA absorbed through the skin could relieve pain, but it seems extremely unlikely. It is just as likely that massaging the area or a placebo effect could account for the benefits reported by those who used it. The Merriam-Webster definition of Chinese water snake oil could indeed be accurate.
References
- Merriam Webster. Snake oil. Accessed September 26, 2024. https://www.merriam-webster.com/dictionary/snake%20oil
- de Loeches J. Tyrocinium pharmaceuticum. Complutense University of Madrid, Typographia Joannis Jolis, 1751. Digitized December 16, 2008. Wikipedia translation accessed September 24, 2024.
- Transcontinental railroad. History.com Editors. Original April 20, 2010, updated September 11, 2019. https://www.history.com/topics/inventions/transcontinental-railroad
- Pearson RA. Misbranding of “Clark Stanley’s Snake Oil Liniment.” United States Department of Agriculture. Bureau of Chemistry. Service and Regulatory announcements. Supplement 29. Issued October 17, 1917. Notice 4944. P. 592. Google Books. http://goo.gl/a2AXI
- Lee TH, Hoover RL, Williams JD, Sperling RI, Ravalese J III, Spur BW, Robinson DR, Corey EJ, Lewis RA, Austen KF. Effect of Dietary Enrichment with Eicosapentaenoic and Docosahexaenoic Acids on in Vitro Neutrophil and Monocyte Leukotriene Generation and Neutrophil Function. N Eng J Med 1985;312(19):1217-24. doi: 10.1056/NEJM198505093121903
- Kunin RA. Snake oil. Letter to the editor. West J Med. 1989;151(2):208. PMID: 2773477. PMCID: PMC1026931
- Graber C. Snake oil salesmen were on to something. Scientific American. November 1, 2007. Retrieved October 13, 2024. https://www.scientificamerican.com/article/snake-oil-salesmen-knew-something/
- Gandhi L. A history of snake oil salesmen. NPR Code Switch, August 26, 2013. Retrieved October 13, 2024. https://www.npr.org/sections/codeswitch/2013/08/26/215761377/a-history-of-snake-oil-salesmen
- Jouris KB, McDaniel JL, Weiss EP. The effect of omega-3 fatty acid supplementation on the inflammatory response to eccentric strength exercise. J Sports Sci Med. 2011;10(3):432-8. doi:10.1249/01.mss.0000354215.91342.08
- Gray P, Chappell A, McE Jenkinson A, Thies F, Gray SR. Fish oil supplementation reduces markers of oxidative stress but not muscle soreness after eccentric exercise. Internat J Sport Nutr Exer Metab. 2014;24(2):206-14. http://dx.doi.org/10.1123/ijsnem.2013-0081
- Tsuchiya Y, Yanagimoto K, Nakazato K, Hayamizu Kochi E. Eicosapentaenoic and docosahexaenoic acids-rich fish oil supplementation attenuates strength loss and limited joint range of motion after eccentric contractions: a randomized double-blind, placebo-controlled, parallel group trial. Eur J Appl Physiol. 2016;116(6):1179-88. doi 10.1007/s00421-016-3373-3
- Tsuchiya Y, Ueda H, Yanagimoto K, Kato A, Ochi E. 4-week eicosapentaenoic acid-rich fish oil supplementation partially protects muscular damage following eccentric contractions. J Internat Soc Sports Nutrition. 2021;18(1). doi.org/10.1186/s12970-021-00411-x
- Cordingley DM, Cornish SM. Omega-3 fatty acids for the management of osteoarthritis: A narrative review. Nutrients. 2022;14(16):3362. doi.org/10.3390/nu14163362
- Deng W, Yi Z, Yin E, Lu R, You H, Yuan X. Effect of omega-3 polyunsaturated fatty acids supplementation for patients with osteoarthritis: a meta-analysis. J Orthop Surg Res. 2023;18:381. doi.org/10.1186/s13018-023-03855-w
- Goldberg RJ, Katz J. A meta-analysis of analgesic effects of omega-3 poly unsaturated fatty acid supplementation for inflammatory joint pain. Pain 2007;129(1):210-23.doi: 10.1016/j.pain.2007.01.020
- Bahadori B, Uitz E, Thonhofer R, Trummer M, Pestemer-Lach I, McCarty M, Krejs GJ. ω-3 Fatty acids infusions as adjuvant therapy in rheumatoid arthritis. JPEN 2010;34(2):151-5. doi.org/10.1177/0148607109342130
- Phillips T, Childs AC, Dreon DM, Phinney S, Leeuwenburgh C. A dietary supplement attenuates IL-6 and CRP after eccentric exercise in untrained males. Med. Sci. Sports Exerc. 2003;35(12):2032-7. doi: 10.1249/01.MSS.0000099112.32342.10
- Li J, Pora BLR, Dong K, Hasjim J. Health benefits of docosahexaenoic acid and its bioavailability: A review. Food Sci Nutr. 2021;9:5229-43. doi: 10.1002/fsn3.2299
- Yi M, You Y, Zhang Y, Wu G, Karrar E, Zhang L, Zhang H, Jin Q, Wang X. Highly valuable fish oil: formation process, enrichment, subsequent utilization, and storage of eicosapentaenoic acid ethyl esters. Molecules. 2023;28(2):672. doi.org/10.3390/molecules28020672
- Jeong WY, Kwon M, Choi HE, Kim KS. Recent advances in transdermal drug delivery systems: a review. Biomaterials Research. 2021;25:24. doi10.1186/s40824-021-00226-6
- Puglia C, Tropea S, Rizza L, Santagati NA, Bonina F. In vitro percutaneous absorption studies and in vivo evaluation of anti-inflammatory activity of essential fatty acids (EFA) from fish oil extracts. Internat J Pharm 2005;299(1-2):41-8. doi:10.1016/j.ijpharm.2005.04.031
JAYANT RADHAKRISHNAN, MBBS, MS (Surg), FACS, FAAP, completed a Pediatric Urology Fellowship at the Massachusetts General Hospital, Boston following a Surgery Residency and Fellowship in Pediatric Surgery at the Cook County Hospital. He returned to the County Hospital and worked as an attending pediatric surgeon and served as the Chief of Pediatric Urology. Later he worked at the University of Illinois, Chicago from where he retired as Professor of Surgery & Urology, and the Chief of Pediatric Surgery & Pediatric Urology. He has been an Emeritus Professor of Surgery and Urology at the University of Illinois since 2000.
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