Juice fasting, also known as juice cleansing, is a controversial fasting method and a detox diet in which a person consumes only fruit and vegetable juices to obtain nutrition while otherwise abstaining from food consumption. Juice fasts may last anywhere from a few days to several weeks.
Reasons for fasting
Reasons to undergo juice fasting may include spiritual or religious reasons, alleged detoxification, a desire to lose weight, or attempts to stop habitual behavior such as smoking, drinking soda, overeating, or caffeine addiction. Participants may use juice fasting as an alternative medicine. Participants may believe juice fasting will cure chronic pain, cancer, depression, arthritis, severe infections that resisted antibiotics, autoimmune diseases, and many other diseases. One reason for juice fasting is to assist with other methods of gallstone passage. Others choose juice fasting because they believe they can focus on healing specific organs and systems.
Some practitioners fast bi-annually in week-long (or longer) periods to attempt to purify the body in synchronization with what they believe to be annual cycles of nature. Fasts may even involve retreats and travel, such as with popular week-long spa-resort style trips to Thailand.
Because pure juice contains little to no fiber, juice fasters may use enemas or herbal or saltwater laxatives during the time of fasting to efficiently expel waste from the intestines and colon. Another method to achieve this effect involves mixing psyllium husks in with the juice. Because psyllium is not absorbed by the body, but greatly increases in volume upon water absorption, it creates the bulk necessary to facilitate evacuation.
To avoid excess sugar and maintain a high nutrient value juices should contain a healthy proportion of 80% vegetables to 20% fruits. The maximum shelf life of a juice is 72 hours and consuming it within that period is highly encouraged.
In a reduced-calorie study, participants juice-fasted for one week without limitation of physical activity. The study demonstrated a temporary reduction in total free cholesterol. However it was also noted that within a week of ending the fast cholesterol had returned to prefast levels.
A systematic review of three randomized controlled clinical trials of fasting published in the Journal of American of Clinical Nutrition in 2015 concluded, "Clinical research studies of fasting with robust designs and high levels of clinical evidence are sparse in the literature. Whereas the few randomized controlled trials and observational clinical outcomes studies support the existence of a health benefit from fasting, substantial further research in humans is needed before the use of fasting as a health intervention can be recommended."
Possible side effects
Fasters should take care to maintain their intake of vitamins and nutrients during fasting, though no specific side effects are associated exclusively with juice fasting. Juice mixes containing grapefruit juice may also adversely interact with certain prescription drugs.
As a detox diet
Scientists, dietitians, and doctors regard detox diets as less effective than water-fasting, and hence a waste of money. Catherine Collins, Chief Dietician of St George's Hospital Medical School in London, England, states that "The concept of ‘detox’ is a marketing myth rather than a physiological entity. The idea that an avalanche of vitamins, minerals, and laxatives taken over a 2 to 7 day period can have a long-lasting benefit for the body is also a marketing myth." Detox diets, depending on the type and duration, are viewed as potentially dangerous and can cause various health problems including muscle loss and an unhealthy re-gaining of fat after the detox ends.
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- Debunking detox
- The Truth About Detox Diets