Copper and Human Health

Copper has been used for medicinal purposes for thousands of years, dating back to the Egyptians and Chinese, who used copper salts therapeutically. Copper also has been used historically for the treatment of chest wounds and the purification of drinking water. Today, copper is used as an antibacterial, antiplaque agent in mouthwashes and toothpastes. The recommended dietary allowance (RDA) for copper was updated in 2001 to 900 μg day^-1. Because copper is extremely important during fetal and infant development, during pregnancy and lactation, women are encouraged to consume 1000 to 1300 μg Cu day^-1. The World Health Organization (WHO) and the Food and Agricultural Administration (FAA) suggest that the population mean intake of copper should not exceed 12 mg day^-1 for adult males and 10 mg day^-1 for adult females. The Tolerable Upper Intake Limit for copper intake is 10 mg day^-1. The adult body can contain between 1.4 and 2.1 mg Cu kg^-1 of body weight (120).

Copper tends to be toxic to plants before their tissues can accumulate sufficient concentrations to affect animals or humans (125). Copper deficiency from foodstuffs derived from plants and animals exposed to low copper levels is more of a concern. The typical diet in the United States provides copper at just above the lower limits of current RDA levels. The richest food sources of copper include shellfish, nuts, seeds, organ meat, wheat bran cereals, whole-grain cereals, and naturally derived chocolate foods (120).

Roots, flowers, and leaves of the folk and naturopathic herb species, wormwood (Artemisia absinthium L.) and white sage (A. ludoviciana Nutt.) in Manitoba, Canada, accumulated considerable copper (14.3 to 24.7�g g^-1 dry weight), indicating their potential importance for medicinal use (37).