The term “snake oil” is used to describe any worthless pseudo-medical remedy promoted as a cure for various illnesses. By extension, snake oil salesmen are charlatans who sell such fraudulent goods.
In 19th century America, snake oil was commonly promoted as a cure-all. It was supposedly produced by boiling rattlesnakes and skimming off the oil that rose to the surface. But although it was sometimes prepared in this way, hucksters found it cheaper and easier to substitute other oils.
Sales of alleged rattlesnake oil continued into the 20th century. In 1915 the US government ordered the analysis of a well-known product, Clark Stanley’s Snake Oil Liniment. The analyst found that its main constituents were “a light mineral oil (petroleum product) mixed with about 1 per cent of fatty oil (probably beef fat), capsicum, and possibly a trace of camphor and turpentine”. Since the product contained no snake-derived oil, Stanley was taken to court and found guilty of misbranding and misrepresenting the product. He was fined $20 — the equivalent of about $430 (£280) today.
Nevertheless, since Clark’s formulation was not unlike modern-day capsaicin-based liniments and chest rubs, it was probably of more use than genuine rattlesnake oil, which has not been shown to have any health benefits.
But where did the belief in snake oil arise? It seems that early American immigrants may have adopted native American customs and also transposed to the rattlesnake an ancient British belief that preparations based on the adder can cure various ills.
These notions would have been reinforced in the 1840s when many Chinese labourers arrived to help build the Transcontinental Railroad. They would almost certainly have brought with them oil from the Chinese water-snake (Laticauda semifasciata, black-banded sea krait), which in traditional Chinese medicine has been used for centuries as an anti-inflammatory agent to treat arthritis, bursitis and other joint pains. These labourers may have offered snake oil to fellow workers as relief for enduring long days of physical effort.
Modern-day research suggests that Chinese water-snake oil may indeed have health benefits because of its high content of omega-3 fatty acids. In 1989 an analysis of snake oil bought in San Francisco’s Chinatown found that it contained 20 per cent eicosapentaenoic acid, which is more than is found in popular omega-3 food sources such as salmon.
Omega-3 fatty acids have been shown to reduce inflammation and are alleged to offer many other health benefits. Although many of the claims made for them — often by the modern equivalent of the snake oil salesman — are unproven, it does appear that they may help in lowering systolic blood pressure, improving cognitive function, reducing the risk of dementia and relieving depression.
A few years ago, researchers in Japan evaluated the effect of Chinese sea-snake oil on a number of outcomes in mice. They found that, compared with lard, snake oil significantly improved the rodents’ maze-learning ability and swimming endurance.
So it seems that snake oil salesmen may not be such mountebanks after all, provided they sell the right sort of oil for the right indications.