Water-only fasts are controversial for medical reasons, but juice fasting provides more nutrients and less exposure to common allergens than the normal American diet.
Health claims made for juice therapies on late-night television may be exaggerated, but for the person fighting chronic hay fever, asthma or other respiratory problems, several days of drinking freshly made juices may bring a welcome respite from symptoms. Instead of resuming your normal diet all at once, introduce foods one at a time and monitor your reaction. Every person's response to foods and food groups is unique, and this is a simple way to test foods and their effects on the body. Experts on juice fasting recommend avoiding the juice of any fruit or vegetable you may be allergic or sensitive to, diluting juices with high sugar content, such as carrot or beet juice, with low sugar juices, such as celery; diluting fruit juices with an equal amount of water; and avoiding juice fasting if you are pregnant or lactating. Medical supervision is recommended for diabetics and others with serious illnesses.