Starting an olive oil habit could be as healthful as kicking a smoking habit. And the proof is in your urine.

Microscopic substances in your urine reveal how well your body is defending against everyday cancer-causing cell damage. Think of the substances as shrapnel -- too much means your body is taking some serious hits. Enter olive oil. In a study, men who upped their intake had less of the damage-signaling shrapnel in their urine samples. How much less? The drop was similar to what smokers experience when they quit. Now that's some potent oil.

Olive oil is full of good-for-you substances. So which one is responsible for the cancer-fighting effects? Until this recent study, researchers suspected it was the phenolic compounds in the oil; phenols have antioxidant (read anticancer) properties. But the phenolic content of the oils seemed to have little impact in this study. Three different types of oil with varying amounts of phenolic compounds were tested, and the type made little difference in the amount of cell-damage markers found in urine samples. Researchers suspect there is something anticarcinogenic about monounsaturated fat, in and of itself.

Which would mean that olive oil, rich in monounsaturated fat, is not only a heart helper but may also deter cancer. That helps explain why, compared to Northern Europeans, Southern Europeans, whose diets tend to overflow with the oil, have lower rates of both heart disease and cancer.

But one caveat to keep in mind: The men in the study didn't add olive oil to their diets. They used it to replace the fats they normally consume -- about 5 teaspoons total per day. Use olive oil to chase out the butters, margarines, and shortenings in your diet so you don't increase your overall calorie count; if you go overboard on calories, you're looking at a different set of health problems.

Recipe Corner
For a double dip of olive goodness, try this delicious Orange and Black Olive Salad -- it has both black olives and olive oil, and the sweet orange balances the Mediterranean flavors.

Find more recipes at EatingWell.com.