An ancient Asian remedy became synonymous with American peddlers' medicinal scams… but some kinds share fish oil's key curative characteristic
by Craig Weatherby
The hype surrounding some dietary supplements is just that, with results falling short of promises.
And most of us dismiss these scams as “snake oil”. This pejorative shorthand for quack remedies dates back to the late 1900's, when patent medicines of dubious provenance and efficacy were commonplace.
This pejorative term for quack remedies dates back to the late 1900's, when patent medicines of dubious provenance and efficacy were commonplace.
But surprisingly, snake oil probably wasn't—and isn't—a medical fraud.
Snake oil arrived in the American West after the Civil War, brought there by Chinese laborers as a traditional topical remedy for arthritis and other joint ailments.
Because it was among the most exotic of the Chinese remedies, and because European-Americans assumed that Asian medicine was superstitious nonsense, it seemed natural to label as “snake oil” all bogus cures—including the many bogus patent medicines peddled by white traders.
Now, snake oil's disreputable image seems ready for reversal.
Based on their fish-like fatty acid profiles, the sea-snake oils used in Chinese liniments may constitute very reasonable remedies for joint problems
Snake oil's secret isn't obscure anymore
Compared with fatty, cold-water fish like Salmon, the water-snake oil used in Chinese traditional medicine are even richer in EPA: the marine omega-3 proven to exert substantial inflammation-moderating effects.
This is no surprise, because, like predatory ocean fish and marine mammals, these ocean-going reptiles eat fish. Sea snakes use the flexible, high-energy omega-3s they obtain from their fishy diets to maintain the fast metabolisms needed to survive in frigid seas.
Compared with omega-3s produced in terrestrial leaves and aquatic algae and plankton, omega-6 fatty acids—which predominate in seeds, nuts and grains— become stiffer and slower at cold temperatures.
In the late 1980's, San Francisco psychiatrist Richard Kunin, M.D. hypothesized that the oil from fish-eating sea snakes might be high in omega-3s, which would explain its long use in Chinese medical practice as a topical anti-inflammatory agent.
He also knew that, like all long-chain fatty acids, omega-3 EPA is absorbed through the skin, making topical use as a joint balm eminently practical.
Dr. Kunin obtained snake oil liniment in San Francisco's Chinatown and sent it off to be analyzed along with oil from two species of rattlesnake, for comparison.
The tests proved that—like most fish oils—the snake oil in standard Chinese liniments ranked high in omega-3 EPA: the long-chain “marine” omega-3 from which the body produces inflammation-moderating chemical messengers called series-3 prostaglandins:
ALA EPA DHA LA GLA DGLA AA Chinese Sea-Snake Oil 0.001 19.6 0.001 4.4 0.001 0.001 2.4 Rattlesnake oil*** 1.0 2.4 2.75 15 0.4 1.4 8.75
Chinese Sea-Snake Oil
In fact, the two sea snakes whose oil is commonly used to make traditional Chinese remedies (Enhydris chinensis and Laticauda semifasciata) rank among the richest known sources of EPA, which is much more powerfully anti-inflammatory, compared with DHA, the other key marine omega-3 in fish oil.
American patent-medicine peddlers of the late 1900's sold liniments labeled "rattlesnake oil", but they were unlikely to contain any. And these dubious remedies wouldn't have done much good if they had. As Dr. Kunin's results demonstrate, the oil of terrestrial serpents such as rattlesnakes is fairly low in omega-3s.
Oil from one kind of sea snake (Enhydris chinensis) consists of up to 20 percent omega-3 EPA, versus an average of six percent EPA in wild Salmon.
And when scientists at the Japanese National Food Research Institute (NFRI) analyzed oil from the other source of snake oil in traditional Chinese medicine—a venomous but mild mannered little serpent called the sea krait (Laticauda semifasciata)—they found high levels of omega-3 EPA (Shirai N et al 2002).
(Wild Salmon oil compensates by being far richer in DHA: the marine omega-3 essential for optimal brain and eye function, whose cardiovsacular benefits complement and rival those of EPA.)
And in two recent studies, the same NFRI team reported that dietary sea krait oil enhanced maze-learning ability and swimming endurance in mice, compared with mice fed lard (Zhang G et al 2007; Shirai N et al 2006).
So next time you need to denounce a bogus cure, just call it a fraud, and leave snake oil out of it!
- Kunin RA. Snake oil. West J Med. 1989 Aug;151(2):208.
- Zhang G, Higuchi T, Shirai N, Suzuki H, Shimizu E. Effect of Erabu sea snake (Laticauda semifasciata) lipids on the swimming endurance of mice. Ann Nutr Metab. 2007;51(3):281-7. Epub 2007 Jul 9.
- Shirai N, Higuchi T, Suzuki H, Shimizu E. Effect of lipids from Erabu sea snake, aticauda semifasciata, on plasma glucose, insulin, and adipocytokine concentrations of normal and streptozotocin-diabetic mice.Ann Nutr Metab. 2006;50(5):425-32. Epub 2006 Jul 17.
- Shirai N, Suzuki H, Shimizu R. Fatty acid composition of oil extracted from the fat sack of the Erabu sea snake Laticauda semifasciata in the Pacific Ocean and South China Sea. Fish Sci 68 (1), 239–240, February 2002.
- Graber C. Strange but True: Snake Oil Salesmen Were on to Something. Scientific American, November 1, 2007. Accessed online November 10, 2007 at http://www.sciam.com/article.cfm?chanID=sa011&articleID=F7B4BAF7-E7F2-99DF-3870FFECA70C38C9