It started with the Tansy cakes. I had to ask myself 'Why would anyone eat anything so utterly disgusting in taste'? Chrysanthemum Vulgare is a common perennial in the British Isles and the name Tansy is said to be derived from the Greek 'athansia', meaning 'immortal'. Reasons suggested for this include the fact that the dried flower lasts forever or that it has a medicinal quality contributing to long life. Looking back to Greek literature, Tansy was given by the Gods to Ganymede to make him immortal. In the language of flowers the gift of Tansy means 'Rejected address' - " I am not interested in you". Its strange taste, not unlike the smell of 'mothballs' might have something to do with this.
Tansy certainly had a reputation as a vermicide and vermifuge (killing and dispelling intestinal worms) in the middle ages. John Gerard wrote in his 17th century Herball:
"In the Spring time are made with the leaves here of newly sprung up, and with eggs, cakes of Tansies, which be pleasant to taste, and good for the stomacke. For if any bad humours cleave there unto, it doth perfectly concoct them and scoure them downewards".
Tansy was a common kitchen garden herb for medicinal and culinary use, in place of expensive foreign spices such as nutmeg and cinnamon. It was used to flavour custard, cakes, milk puddings, omlettes and freshwater fish. In Ireland it was included in sausages called 'Drisheens'. Its use as a springtime 'cleanser' became ritualised into a part of the Christian religious Easter traditions;
"On Easter Sunday be the pudding seen, To which the Tansy lends her sober green."
The consensus on this much written about herb is that it was used at Easter to purify the blood after lent. This consensus shows a problem though, in that in England the plant does not show leaves until the end of May - well after Easter. This is evidence of the assimilation of natural 'self-medicating' herbalism into a controlling religious patriarchy.
Observation of wild and domesticated animals shows that they regularly self-medicate with wild plants. Sick chimpanzees chew bitter leaves from a bush not normally part of their diet, and then recover. Research by Michael Hoffman shows that a particular nematode worm is common in the monkey's gut during the rainy season and that their chewing of the leaves coincided with the prevalence of this parasite, which it destroyed. This was the same bush that local tribes use to get rid of stomach parasites.
Dogs and cats self medicate by eating couch grass or cleavers. Parrots, chickens, camels, snow geese, starlings - all have been observed consuming substances normally alien to their diet to remedial effect. Bears particularly are venerated by North American Indian culture because they symbolise the powers of 'regeneration'. North American Indians discovered the use of a root called Osha from bears. It is so effective as an all round painkiller, antiviral, antipeptic that it is now on the endangered species list.
The Woolly Bear caterpillar has also been observed to change its diet according to whether it is infected by a particular parasite. Normally a Lupin eater, the caterpillar increases its chance of surviving a particular fly parasite by changing to a diet of Poison Hemlock. Self-medication is not therefore a 'rational choice' in other species, but a carefully integrated part of a survival mechanism against an invisible predator - disease. Humans seem to have lost this sense of their own health and are not usually informed as to the uses of plants growing around them.
Humans often self-medicate though - alcohol indulgence to deal with stress being an obvious example of this or the ready availability of pharmaceutical or street drugs. We often consume substances such as caffeine or sugar drinks for easy energy. The natural trait towards self-medicating may well be at the basis of many of our unconscious 'eating choices'. Potatoes contain a form of opiate and all foods to some extent can act as 'alteratives' to a unique physiology. We talk about comfort foods and rewarding ourselves with treats to eat. Often we might have a favourite food that can help if we feel too ill to eat, like scrambled egg. This is a unique food because it contains all of the amino acids we need to digest it. Chocolate is to many the ultimate comfort food treat.
An extreme example of what we do is shown in 'Pica' where a person gets uncontrollable desires to eat certain edible (and inedible) substances. This condition is occurs in pregnant women and is thought to express the need for particular minerals. Because our food sources are often limited to processed food, and because of the destruction of herbal folk-lore and access to wild medicine, many of us have lost touch with our 'health sense' or ability to use food or wild plants as preventative or curative self-medication.
But finally the wheel is turning and people want access to this more holistic and gentle sense of health that is prevalent in other medical philosophies such as Chinese or Tibetan. If you like the taste of mothballs you could even try Tansy cakes.
Article with thanks to Roger Phillips and Michael Hoffman