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, 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 uses of plants growing around them.

Humans often self-medicate though - alcohol indulgence to deal with stress being an obvious example of this or 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 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 amino acids we need to digest it. Chocolate is to many 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 occurs in pregnant women and is thought to express need for particular minerals. Because our food sources are often limited to processed (and demineralised) food, and because of destruction of herbal folk-lore and access to wild medicine, many of us have lost touch with our 'health sense' and an ability to use food or wild plants for self-medication. A regular preventative 'detox' was an essential part of our diet at one time and if you like taste of mothballs you could even try Tansy cakes.

Article with thanks to Roger Phillips and Michael Hoffman

Over time I cut out wine, coffee, acid-forming foods but with little improvement. I visited doctor's who endorsed these decisions, told me to go out walking more often and to his credit mentioned that 'there is a nasty little bug called H. Pylori going around' - which started this strand of research for me.

Normally doctors will not treat H. Pylori until it provokes serious gastric illness, and when you see what orthodox medicine prescribes for this treatment its no surprise. At least two anti-biotics, H2 blockers, proton pump inhibitors and a stomach lining protector. Although this prescription may be effective it is also expensive, complex and has unwanted toxic side effects such as nausea, diarrhoea and vomiting -meaning that many people do not finish course (patient noncompliance) and remain infected.

The doctor did not prescribe for me - just told me to cut out acidic forming stuff - which I did. But I also started to experiment to see what would bring relief from continuing symptoms - gastric discomfort, acid reflux, bloating, poor digestion, wind and inflammation. Cutting out wheat based products was most helpful.

Just by 'coincidence' I found out that Pistachio nuts seemed to relieve discomfort. It was no surprise when I found out that Mastic Gum, which comes from a related tree called Pistacia lentiscus is a classic remedy for gut inflammation that has been in use for thousands of years. There is increasing evidence that shows Mastic gum to be effective against H. Pylori, with a range of therapeutic effects on various gastric dis-eases. There have never been any undesirable effects attributed to use of mastic gum. Since chewing this gum I am now completely relieved of any gastric discomfort.

So as I'm writing this article I am chewing small pieces of mastic gum and have adopted this as part of a preventative 'yearly spring detox' for internal parasites. It has a nice woody taste, not unlike smell of sandal wood or cinnamon. In Mediterranean countries mastic gum has been used for centuries for preventing tooth decay, healing mouth and skin ulcers, controlling diabetes and reducing cholesterol levels. Some African sources even attribute aphrodisiac qualities to this most useful of substances - natural chewing gum !

Please note that this article does not replace advice and treatment of your medical practitioner.