Anthropology of herbalism

People on all continents have used hundreds to thousands of indigenous plants for treatment of ailments since prehistoric times. Medicinal herbs were found in the personal effects of an "ice man", whose body was frozen in the Swiss Alps for more than 5,300 years. These herbs appear to have been used to treat the parasites found in his intestines. Anthropology or anthropologists theorize that animals evolved a tendency to seek out bitter plant parts in response to illness.

Indigenous healers often claim to have learned by observing that sick animals change their food preferences to nibble at bitter herbs they would normally reject.Field biologists have provided corroborating evidence based on observation of diverse species, such as chimpanzees, chickens, sheep and butterflies. Lowland gorillas take 90% of their diet from the fruits of Aframomum melegueta, a relative of the ginger plant, that is a potent antimicrobial and apparently keeps shigellosis and similar infections at bay.

Researchers from Ohio Wesleyan University found that some birds select nesting material rich in antimicrobial agents which protect their young from harmful bacteria.

Sick animals tend to forage plants rich in secondary metabolites, such as tannins and alkaloids. Since these phytochemicals often have antiviral, antibacterial, antifungal and antihelminthic properties, a plausible case can be made for self-medication by animals in the wild.

Some animals have digestive systems especially adapted to cope with certain plant toxins. For example, the koala can live on the leaves and shoots of the eucalyptus, a plant that is dangerous to most animals.A plant that is harmless to a particular animal may not be safe for humans to ingest.A reasonable conjecture is that these discoveries were traditionally collected by the medicine people of indigenous tribes, who then passed on safety information and cautions.

The use of herbs and spices in cuisine developed in part as a response to the threat of food-borne pathogens. Studies show that in tropical climates where pathogens are the most abundant, recipes are the most highly spiced. Further, the spices with the most potent antimicrobial activity tend to be selected.In all cultures vegetables are spiced less than meat, presumably because they are more resistant to spoilage.