Eating vegetables--the simple truths.

Eat your vegetables, of course. Who doesn't know that? The fresher the better, and uncooked better than cooked. Right? Not necessarily. There's certainly nothing wrong with a big, fresh salad full of raw, crunchy vegetables. But in many cases, cooked is better than raw, and believe it or not, frozen and canned may be better than fresh.

Because the antioxidants found in vegetables and fruits are known to reduce the risk of cancer and produce a host of other health benefits, there has been lots of research in recent years looking at the bioavailability of those nutrients. Here are some of the results.

* Fresh versus frozen. If you had a theoretical garden in your backyard that could produce a huge variety of fruits and vegetables 12 months a year, then fresh might be better than frozen or canned. But because we rely on the agricultural industry to produce most of our food, and that means long delays between harvest and plate, frozen foods are often superior to fresh. Processing of vegetables straight from the field preserves antioxidants and vitamins far better than the shipping and handling required to get fresh produce to your refrigerator. Even after it arrives in your kitchen, most of us shop only once a week and fresh food can remain in the refrigerator for days. The longer it has been since it was soaking up rays, the greater the potential reductions in food value.

* Raw versus cooked. This may surprise you even more. Assuming equal degrees of freshness, your body may actually be able to use more of the nutrients and phytochemicals in vegetables that have been cooked than in those that are raw. Checking blood levels of subjects after eating either cooked or raw spinach and carrots confirmed that heat releases more beta-carotene from the vegetables and increases the bioavailability of nutrients by as much as five times. This may be because nutrients are locked in plant cell walls and heat helps to break them down.

* Juice versus all the rest. Juice can be another way to eat your vegetables and fruits. Juicing produces the highest levels of antioxidants and other phytochemicals by breaking down the plant cell walls that contain nutrients without the price that using heat imposes.

The bottom line for optimum health--if very fresh produce isn't available, don't shy away from frozen or canned. Quick cooking can unleash valuable nutrients. Take advantage of seasonal, local produce and boost your antioxidant intake with juicing. The more the better, no matter how you slice it.

(Journal of Nutrition, 2000, Vol. 130, No. 3, pp. 503-506, and 1998. Vol. 128, No. 5. pp. 913-916; Cancer and Epiderniotogical Biomarkers, 1999, VoL 8, No. 3, pp. 22 7-231; Journal of the American College of Nutrition, 1999, Vol. 18, No. 5, pp. 426-433)