Rosemary

Source=Leaves of the rosemary plant, Rosmarinus officinalis
Flavor=Very aromatic, faintly lemony and piney
Best used=Fresh or dried
Cooking use=In meat (especially lamb) or fish dishes and sauces or soups.

Rosemary works so well at preventing fats from becoming rancid that the food industry sometimes uses extracts of rosemary oil as a food preservative. Rosemary oil is a strong antioxidant-which means it protects fats from being attacked by oxygen. Because oxygen damage is also known to be a factor in the development of cancer, researchers have been looking at its potential in this area as well.
Several studies done in the last several years show that oil from the leaves of the very plant sold as a spice for flavoring can help prevent the development of cancerous tumors in laboratory animals.
In one study, led by Chi-Tang Ho, Ph.D., professor in the Department of Food Science at Rutgers University in New Brunswick, New Jersey, applying rosemary oil to the skin of experimental animals reduced their risk of cancer to half that found in animals that did not receive the application of oil.
In other studies by the same research team, animals whose diets contained some rosemary oil had about half the incidence of colon cancer or lung cancer compared with animals not eating rosemary. And researchers at the University of Illinois in Urbana found that rosemary cut by half the incidence of breast cancer in animals at high risk for developing the disease.
Rosemary also helps to relax muscles, including the smooth muscles of the digestive tract and uterus. So it's sometimes used to soothe digestive upsets and relieve menstrual cramps. In large amounts, however, it appears to have the opposite effect-causing intestinal irritation and cramping. (In fact, larger doses of rosemary oil and other rosemary preparations can be a risk to pregnancy.)
"We've done studies that looked at both large amounts and smaller amounts in the diet and found benefits even with small amounts," Dr. Ho says. "When animals were fed a diet that contained 2 percent (by weight) of rosemary, we saw significant cancer protection. But when we cut that amount way back, to 1/100th of that amount, rosemary still had a very strong effect. Even just using a fraction of a teaspoon a day could have potential health benefits."
If you prefer a tea, you can make a pleasant-tasting brew with one teaspoon of crushed dried leaves in a cup of boiling water. Let steep for ten minutes.
Avoid using rosemary oil in any amount, though. Even small doses can cause stomach, kidney and intestinal problems, and large amounts may be poisonous.