Summer's fresh vegetables and fruits bathe your taste buds in fabulous flavors. And they're chock full of vitamins, minerals and phytochemicals.

Phyto what?

"The 'phyto' means 'plants,'" said Holly Alley, a nutritionist with the University of Georgia Extension Service. "The plants we eat contain hundreds, perhaps thousands, of chemicals."

Don't be so quick to say "yuck." Phytochemicals are good guys. In fact, they may be one of the best things about some of our favorite foods.

"We don't know exactly what they do," Alley said. "But eating foods with phytochemicals may reduce the risk of certain types of cancer."

Scientists have known for 20 years that people who eat lots of fruits and vegetables are less likely to have most cancers, she said. But they haven't known why.

The answer, or at least some of the answers, may be in the phytochemicals. Researchers are studying this group of compounds to find out exactly how they affect people's health.

So far, they're pretty sure they're not like vitamins.

"Vitamins are essential chemicals in foods that prevent and cure specific diseases," Alley said. "For instance, if you don't get vitamin C in your diet, you'll get scurvy. And if you get scurvy, taking vitamin C will cure it."

If you don't get phytochemicals in your diet, you won't necessarily get cancer. "And so far," she said, "there's no evidence that eating foods with phytochemicals will cure any type of cancer."

But the evidence is growing, she said, that these compounds may help protect you against certain cancers. They seem to have a number of functions.

Some, Alley said, may help your body get rid of cancer- causing agents, called carcinogens. Among them are limonenes, found in citrus fruits; ellagic acid, found in grapes; caffeic acid, found in fruits; and allyl sulfides, found in garlic, onion, leeks and chives.

Others may help keep cancer cells from growing. Two of these are protease inhibitors and saponins, both found in beans.

Still others are believed to block estrogen, a hormone that increases the risk of breast and ovarian cancer. These include isoflavones, found in beans; and indoles, found in vegetables such as cabbage, broccoli, Brussels sprouts and greens.

These compounds' names are long and strange now. "But they may become as common as vitamin names in the future," Alley said.

Cooking may destroy a few of the compounds, such as allyl sulfides in garlic. But cooking can actually make some chemicals more available.

"So until we know more," she said, "it's best to eat a variety of both raw and cooked fruits and vegetables. And phytochemicals are one more good reason to eat at least five servings a day."