Vegetable juice is a great source of many nutrients, since vegetables are rich in literally thousands of substances that help to reduce the risk of heart disease as well as many of the most common cancers, such as prostate cancer, breast cancer, and colon cancer. These substances include phytochemicals, bioflavonoids, carotenoids, retinols, capsaicins, lycopene, geninstein, and many, many others. For most people, drinking vegetable juice is a better choice than drinking fruit juice on a regular basis.
Most fruit juicers remove the fiber from the fruit, so the sugar in the fruit is absorbed rapidly.
In some people, this may provoke an insulin response. Besides lowering your blood sugar, insulin accelerates the conversion of calories into triglycerides, which is how your body stores fat. Both fruit and vegetable juices tend to oxidize fairly rapidly, so try to juice only about as much as you need for that day and perhaps the next one. When possible, use organic fruits and vegetables to minimize your exposure to insecticides. Of course, wash the fruits and vegetables thoroughly before juicing them.