Traditional Medicines: How Much is Enough?

Originally appears in the Fall 2009 issue

Before the days of pharmacies and vitamin pills, Aboriginal people harvested plants for medicine and used tonics that contained significant quantities of vitamins and minerals. This exercise is an investigation into early methods of measuring dosages of medicinal tonics. It could form the basis of math and chemistry exercises and provide an opportunity to incorporate lessons on nutrition. The topic is well suited to students in upper elementary or junior high school.

Background

In many Aboriginal cultures, teas served as both refreshing drinks and medicinal tonics. For example, teas made by steeping the needles from various conifers in boiling water are very high in vitamin C and served as a significant source of this nutrient, particularly in winter. It was tea made from eastern white cedar by Mi’kmaq people that cured Jacques Cartier’s crew of scurvy in the winter of 1535–1536.¹ As well as being astringents, conifer needles have antiseptic and stimulant properties due to the monoterpenes in their resins and essential oils. However, conifer needles contain other compounds that are toxic if consumed in large quantities. These are secondary metabolites, such as tannins, produced by plants to discourage herbivores. Because of these secondary metabolites, it is very important to limit consumption of medicinal teas to doses that are appropriate to body size.

Infusions of the needles of tamarack (Larex laricina) or red spruce (Picea rubens) were used by many Aboriginal people as cough remedies or general tonics.² To determine a dose proportional to body size, a branch of the tree was held between the elbow and an outstretched finger.³ Other units of measure used to determine dosage included the width of the fist, the width of the thumb and the distance from forefinger to pinky in an outstretched hand.