The marketing industry makes use of phrases such a “made only from natural ingredients” or “all-natural” to sell a range of products. In making such claims they rely on the myth that anything “natural” is good for us. Perhaps this myth arises from the misguided anthropocentric belief that the natural world was somehow designed to serve humanity (though how lions, tigers and great white sharks fit into this interpretation of the natural world I’m not sure!).
However, if one takes a closer look at the natural world we find it filled many deadly substances capable of taking out not just one, but large numbers of people. Indeed some of the most deadly substance known to us are natural. Across the internet you can find many lists of “the 10 most toxic substances” which vary depending on how one defines “toxic’, however in most of these lists the majority of the 10 most toxic substances occur naturally.
Below are a few of the deadly natural substances that tend to be found on such lists:
While the rich and famous use this toxin to paralyse facial muscles and reduce frown lines, swallowing or inhaling one millionth of a gram will kill you. This toxin is a protein, produced by the bacterium Clostridium botulinum. The lethal nature of this toxin was first observed in relation to the poisoning that can occur with improperly prepared meat products.
One of the toxins associated with paralytic shellfish poisoning (PSP) a dose of around 0.5 mg is lethal if swallowed, though it is at least 10 x more lethal by injection. Saxitoxin is a much smaller molecule than the botulinum toxin.
saxitoxin structure (from Wikipedia)
Tetradotoxin is most commonly associated with the Japanese delicacy, the puffer fish (though it is found in a range of animal species). If prepared incorrectly, the puffer fish can become contaminated with tetradotoxin from the fish’s liver. Early numbness may be followed by vomiting and then paralysis, with death occurring anywhere between 20 minutes to 8 hours. There is no known cure for tetradotoxin poisoning and the lethal dose has been estimated to be around 25 mg for average human being. One of the earliest cases of tetradotoxin poisoning may have been observed by Captain James Cook in Septemver 1774, when some of Cook’s crew consumed local fish. While the crew suffered only numbness and shortness of breath, the pigs who consumed all of the leftovers and discarded material were dead by the following morning.
Tetradotoxin structure (from wikipedia)
In 1978, Bulgarian dissident, Georgi Markov was walking on London when he felt a sharp pain in his thigh. Three days later he was dead. An autopsy found a small pellet in this thigh containing traces of ricin. The assassination was attributed to the Bulgarian secret police, though KGB defectors have stated that the KGB assisted in providing the technology. This case has been referred to as the “Umbrella murder” as it is believed the pellet was shot from a mechanism concealed in an umbrella.
Ricin is a naturally occurring protein extracted from the castor oil plant. It has a lethal dose of less than 2 mg for an overage human being if injected or inhaled.
Tetanospasmin, is the deadly toxin produced when a wound is infected with Clostridium tetani. The resulting condition, tetanus, is also referred to as lockjaw, due the muscular spasms which occur in the jaw and other parts of the body. The lethal dose is similar to that of botulinum (1 millionth of a gram).
Aflatoxins, produced by the fungus, Aspergillus, are a range of different toxin molecules, some of which are lethal at sub-milligram quantities.
Aflatoxin B1 structure (Wikipedia)
So the next time you hear phrases such as “natural – it’s got to be good for you”, spare a thought for these toxins.