Since the Middle Ages, herbalists have used milk thistle to nourish the liver, an organ in charge of converting food to energy and clearing toxins from the blood. Now lab tests from the University of California, Irvine, have shown that silibinin -- a major milk thistle compound -- can fight liver cancer, partly by slowing the growth of cancer cells.Milk thistle may also treat liver conditions like hepatitis and cirrhosis, according to several previous studies.

Deb Soule, author of A Woman's Book of Herbs, finds that most people can benefit from a daily dose of the herb, known to restore healthy liver function after exposure to environmental toxins. "Good liver function gives us good energy," says Soule, who recommends grinding up 1 to 3 tablespoons of milk thistle seed in a coffee grinder and stirring it into your cereal each morning. (Order seeds from mountainroseherbs.com.) If you'd prefer to take a tincture, try a quarter to a half teaspoon three times daily.