If you're a juicer.

Many juices make delicious and healthful drinks that can replace nutrient-deficient, expensive carbonated beverages. Frozen juices and purees can also be used to make healthful desserts that can be as smooth as ice cream and less expensive than a smoothie.

But one of the main reasons for the increasing popularity of "juicing" is the belief that "drinking your food," or consuming large quantities of fresh fruit and vegetable juices, increases health and vitality.

True, getting plenty of fruits and vegetables each day is the right idea, but doing so mainly through juice may not be the best solution.

One advantage of juicing is that it speeds meal preparation and consumption, and, there may be times in our busy schedule when speed is a consideration. Yet as a general rule, it is better to eat slowly, allowing absorption of food to raise the arterial glucose level, in this way signaling satiety (a sense of "fullness") before too much is eaten. In addition, allowing the food longer contact with the tongue and the odors longer contact with the receptor cells lining the back of the nose prolongs the enjoyment of flavor.

Juicing may allow you to eat more fruits and vegetables, but keep in mind that overconsumption of orange pigment-containing fruits and vegetables can actually discolor the skin. This condition is known as "carotenemia," harmless but unsightly. You generally wouldn't eat enough carrots to turn your skin yellow, but how easy it is to drink enough carrot juice to develop carotenemia. You probably would not eat enough apples to cause hyperglycemia, but it's easy to drink enough apple juice to do this.

Another concern is that if one fruit or vegetable is overconsumed, others may be underconsumed, and you may not get all the required nutrients. Eating a wide variety of principally unrefined foods helps ensure adequate nutrition.

Juicing may improve the absorption of certain nutrients (some nutrients may be better absorbed with decreased fiber),(*) but remember that fiber has been shown to play an important role in decreasing the risk of colon cancer and an essential role in the health of the intestinal cells.

What about those "helpful enzymes" preserved by juicing?

Every cell in our body contains the enzymes necessary for its own work. Since a cell is too tiny to hold all the enzymes it might ultimately use, it makes an enzyme only when it needs it.

Plant enzymes function well in the work of the plant cell, but generally speaking, our cells have different functions from those of plants.

As for plant enzymes as a digestive aid, ordinarily the are not beneficial. Their function in the plant has not been that of breaking down large molecules such as we find in our food. In addition, since the plant enzymes are proteins, they will be broken down to amino acids during digestion.

If you're a juicer because "raw food is good for you," you have a point. In general, it is nutritionally advantageous to consume some raw food each day to help supply vitamins C and B[sub.6]. However, not all food should be eaten raw. Some raw foods (mature beans, eggs, etc.) contain toxic substances that can be inactivated by cooking. Cooking also destroys many disease-causing microorganisms.

The best advice is to use common sense. Juice can be safely consumed in moderate amounts, but large quantities can actually undermine good health.

(*)Some juicers take out more fiber than others.