Juice Fasts


Juice fasts, sometimes called juice therapy, are short-term dietary practices, typically one to three days in length, during which a person voluntarily consumes only fruit, vegetable, or other plant juices; their extracts; or fruit teas.


The diet consists of drinking between 32 and 64 ounces of juice per day.

The diet consists of drinking between 32 and 64 ounces of juice per day.

The second major influence on the popularity of juice fasts in Canada and the United States is naturopathy, which is an approach to health care that developed out of the natural healing movement in Germany and North America in the late nineteenth century. Naturopaths of the twenty-first century use a variety of techniques in treating patients, including hydrotherapy, spinal manipulation, and physical therapy, as well as nutritional and dietary advice. Like Ayurveda, naturopathy emphasizes prevention of disease and recommends noninvasive treatments that rely on the body's own self-healing powers. Juice fasts are an important part of naturopathic dietary therapy.

The third factor that has contributed to interest in juice fasts is that fasting is used in nearly every religion of the world, including Christianity, Judaism, Buddhism, and Islam. Many of history's great spiritual leaders fasted for mental and spiritual clarity, including Jesus, Buddha, and Mohammed. In one of the famous political acts of the previous century, the Indian leader Mahatma Gandhi fasted for 21 days to promote peace. It is only since the 1970s that juice fasting has been advocated by secular writers as a treatment for obesity.


A juice fast can be done for several reasons: to cleanse the body of heavy metals and other chemical toxins; as a practice related to Ayurvedic medicine; as the first step in the treatment of colitis, arthritis, depression, cancer, HIV infection, or other diseases; for weight reduction; as part of a vegetarian, fruitarian, or vegan lifestyle; or as a part of a general program of eliminating other unhealthy habits such as smoking, drinking large amounts of alcohol or caffeinated beverages, and overeating. Some people drink large amounts of freshly extracted fruit or vegetable juices as part of their regular diet without necessarily abstaining from solid foods, a practice known as “juicing.” Many people who undergo juice fasts combine them with massage therapy or the use of laxatives and enemas to completely relax the body and cleanse the digestive tract.


Most practitioners of juice fasting recommend restricting it to the warmer months of the year or traveling to a spa in a warm climate for a wintertime juice fast. Most people undergo juice fasting only once or twice a year; however, some undergo a one-day juice fast every week, or a two-day fast once a month.

Beginning 7 to 10 days before the fast, the person should reduce intake of or eliminate entirely all stimulants (coffee, tea, cocoa, and cola drinks), alcoholic beverages, animal meats, fish, eggs, dairy products, sugar, and wheat. The diet during this preparation period should consist entirely of organic fruits, vegetables, and beans.

Making and consuming the juice

The dieter is instructed to drink between 32 and 64 ounces of juice per day, with 6 glasses of warm filtered water in addition. Some therapists recommend one or more cups of herbal tea each day in addition to the juice and water. The juice should be made in a juicer from fresh organic produce; prepackaged juices should not be used, because they are pasteurized to retard spoilage. The heat required for pasteurization destroys some of the vitamins and enzymes in the fruit. If organic fruits and vegetables are unavailable, ordinary supermarket produce may be used, provided it is peeled or washed in a special produce cleaner (available at health food stores) to remove pesticide residue. A combination of fruits and vegetables is recommended rather than fruit or vegetable juice alone. The juice should be consumed within half an hour of processing in the juicer, because the natural enzymes in the fruits or vegetables begin to break down the other nutrients in the juice after that time. It should not be refrigerated.

There are a number of recipe books for combining fruit and vegetable juices to make the fast as tasty as possible. Fruits and vegetables that are commonly recommended for juicing include:

Bowel care

An important part of juice fasting is the use of laxatives or enemas to cleanse the lower digestive tract, because the juice does not supply enough fiber to keep the bowels moving. Because many practitioners believe that juice fasts are necessary to detoxify the body, the removal of wastes is considered essential to prevent the toxins in the digestive tract from being reabsorbed into the bloodstream. Some juice therapists recommend mixtures of slippery elm or other herbs to cleanse the colon; others prefer saltwater laxatives, enemas, or colonics for cleansing the bowel.

A colonic is a procedure in which a large amount of water, sometimes as much as 20 gallons, is infused into the colon through the rectum a few pints at a time. It differs from an enema in that much more fluid is used; and a colonic is infused into the colon, whereas an enema infuses water or a cleansing solution into the rectum only. Mainstream physicians do not recommend colonics on the grounds that they are unnecessary, based on a nineteenth-century misunderstanding of the process of digestion, and can be uncomfortable for the patient. In some cases, they pose serious risks to health.

Breaking the fast

People taking a juice fast are advised against returning to solid foods immediately at the end of the fast because the intestines need time to readjust to grains and other solid foods. One sequence of breaking the juice fast through a gradual return to a full diet is as follows:


People may undergo juice fasting for one or more of the following reasons:

Spiritual or religious practice

Some people find a juice fast to be useful as part of a general religious or spiritual retreat. The first stage of an Ayurvedic pancha karma includes extra time given to meditation and nature walks as well as gradual exclusion of stimulants and solid foods from the diet. Those who undertake a juice fast to wean themselves from smoking, drugs, or a food addiction are also often looking for spiritual as well as physical release from the habit. Many people report relief from emotional stress as a side benefit of juice fasting.

Weight loss

Many people turn to juice fasts for quick weight loss. During a juice fast, however, individuals will not lose weight if they take in an abundance of calories from the fruit and vegetable juices. Most experts recommend a combination of reducing calories, choosing healthy and nutritious foods, and engaging in regular physical activity as the best method of weight loss.


Naturopaths frequently recommend juice fasting as a way of ridding the body of various toxins, which they identify as coming from several sources:

The traditional system of natural medicine that originated in India around 3500 BCE. Its name is Sanskrit for “science of long life.” Juice fasts can be traced back to Ayurvedic practice.
The rate at which a substance or chemical is absorbed into the body or made available for a specific physiological process. Juice fasting sometimes affects the bioavailability of prescription medications.
Sometimes called colonic hydrotherapy, a colonic is a procedure similar to an enema in which the patient's colon is irrigated (washed out) with large amounts of water. Some people undergoing a juice fast have one or more colonics to remove fecalmatter remaining in the intestines during their fast; however, this procedure is discouraged by mainstream physicians because of its potential risks to health.
Detoxification diets—
A group of diets that are followed to purify the body of heavy metals, toxic chemicals, harmful microbes, waste products of digestion, and other substances thought to be harmful. Juice fasts are one type of detoxification diet.
A vegetarian who eats only plant-based products, such as fruits, seeds, and nuts, that can be obtained without killing the plant. Many fruitarians make occasional use of juice fasts.
A system of disease treatment that emphasizes natural means of health care, such as natural foods, dietary adjustments, massage and manipulation, and electrotherapy, rather than conventional drugs and surgery. Naturopaths (practitioners of naturopathy) often recommend juice fasts as a way of cleansing the body.
Pancha karma
An intensive one- to two-week ritual of detoxification practiced in Ayurvedic medicine that includes enemas, bloodletting, and nasal irrigation as well as fasting.
A process for partial sterilization of milk or juice by raising the liquid to a temperature that destroys disease organisms without changing the basic taste or appearance. Pasteurized fruit or vegetable juices are considered unsuitable for juice fasts on the grounds that pasteurization destroys important nutrients in the juices.
A hotel or resort for relaxation or health- and fitness-related activities. Some people undergoing a juice fast do so at a spa to combine the fast with colonics, massage therapy, or other practices associated with juice fasts. The English word spa comes from the name of a famous health resort in Belgium.
A vegetarian who excludes all animal products from the diet, including those that can be obtained without killing the animal. Vegans are also known as strict vegetarians. Some vegans practice juice fasting.
Treatment of specific illnesses

Juice fasting is sometimes recommended by non-medical professionals for treating specific diseases and disorders, most commonly arthritis, autoimmune disorders, and depression, but it has also been claimed to be an effective treatment for severe infections (including AIDS), multiple sclerosis, and cancer. One theory that is sometimes advanced to explain the healing power of juice fasting is that the energy normally used digesting heavy or high-protein meals is instead directed to the body's natural self-healing capacity. The medical profession does not recommend juice fasting as a means of disease treatment, especially for such chronic conditions as cancer or HIV infection.



In general, anyone considering a juice fast should consult a health professional beforehand. Some groups of people, however, should not undertake a juice fast, including:

People taking prescription medications should consult their primary care physician before a juice fast, as the bioavailability of some drugs can be affected by fasting. In addition, grapefruit, apple, orange, pomegranate, and other juices should not be used for a juice fast because the juices of these fruits may increase the blood levels of prescription medications in the body.

Juice fasts should not be extended beyond three or four days without medical supervision, as longer fasts can lead to poor intake of such nutrients as protein and calcium and may cause deficiencies or toxic levels of some vitamins or minerals. In addition, anyone who feels faint or dizzy, develops an abnormal heart rhythm, feels nauseated or vomits, or has signs of low blood pressure should discontinue the fast and consult a doctor at once.

Economically, juice fasting is a potentially expensive form of dietary therapy. Readers interested in juice fasts or juicing as a dietary addition should be prepared to pay between $35 and $200 for a juicer or juice extractor, although some deluxe models are marketed for as much as $300. The chief difference is that juice extractors remove the fruit or vegetable pulp from the juice (and are difficult to clean), whereas juicers generally leave the pulp in the juice. In addition to the cost of the machine and the fruits or vegetables to be juiced, people on a juice fast usually need to purchase laxatives or enemas for cleansing the bowel.



The risks of juice fasting are highest in children. For a child, undergoing a juice fast for longer than 1–3 days can result in negative health consequences and even death. An infant should never be placed on a fast of any type for any length of time.

The major risks to health from juice fasts in adults include metabolic crises in patients with undiagnosed diabetes or hypoglycemia; dizziness or fainting due to sudden lowering of blood pressure; diarrhea, which may result in dehydration and an imbalance of electrolytes in the body; and protein or calcium deficiencies, which may occur from unsupervised long-term juice fasts.

Minor side effects of juice fasts include headaches, fatigue, constipation, acne, bad breath, and increased body odor.

Research and general acceptance

Most mainstream medical research done regarding fruit and vegetable juices in the diet is concerned with these juices as one component of a complete adult diet rather than their use for a short-term fast. As of 2018, 28 studies had been registered with the National Institutes of Health on the effects of fruit and vegetable juices on appetite, weight loss, dietary calcium levels, and reduction of sweetened beverage consumption. Almost all research on juice fasting as a specific practice was being conducted by practitioners of Ayurvedic medicine.

People can lower their risk of diseases such as high blood pressure, cardiovascular disease, and type 2 diabetes with a diet high in fruits and vegetables and decreased consumption of red meats, processed meats, and saturated fats. During a juice fast, research shows that a person may help protect the cardiovascular system by increasing the intake of fruits and vegetables that are high in antioxidants and by decreasing the intake of dietary fats, but the benefit is only short term if the person then returns to lower levels of fruit and vegetable consumption.

Although juice fasting is considered a type of fad diet by mainstream medical practitioners, some websites and blogs encourage the practice. As of 2018, however, most juicing websites encouraged dieters to combine three-day juice fasts with longer term weight loss plans.

See also Detoxification diets ; Liquid diets ; Weight cycling .



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Shetty, P., A. Mooventhan, and H. R. Nagendra. “Does Short-Term Lemon Honey Juice Fasting Have Effect on Lipid Profile and Body Composition in Healthy Individuals?” Journal of Ayurveda and Integrative Medicine 7, no. 1 (March 2016): 11–13.


Cross, Joe. Fat, Sick, and Nearly Dead. YouTube. https://www.youtube.com/watch?v=LRtSo-YpWbk (accessed March 7, 2018). This is a three-minute trailer for the 2010 Joe Cross documentary about juice fasting.

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Just On Juice. “7 Day Juice Fast Plan.” JustonJuice.com . http://www.justonjuice.com/7-day-juice-fast-plan (accessed March 7, 2018).

National Center for Complementary and Integrative Health (NCCIH). “Ayurvedic Medicine.” National Institutes of Health. https://nccih.nih.gov/health/ayurveda (accessed March 7, 2018).

National Center for Complementary and Integrative Health (NCCIH). “‘Detoxes’ and ‘Cleanses.’” National Institutes of Health. https://nccih.nih.gov/health/detoxescleanses (accessed March 7, 2018).

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Academy of Nutrition and Dietetics, 120 South Riverside Plaza, Ste. 2190, Chicago, IL, 60606-6995, (312) 899-0040, (800) 877-1600, http://www.eatright.org .

American Association of Naturopathic Physicians (AANP), 818 18th St. NW, Ste. 250, Washington, DC, 20006, (202) 237-8150, (866) 538-2267, Fax: (202) 237-8152, https://www.naturopathic.org .

American Vegan Society (AVS), 56 Dinshah Lane, PO Box 369, Malaga, NJ, 08328, (856) 694-2887, Fax: (856) 694-2288, http://www.americanvegan.org .

National Ayurvedic Medical Association (NAMA), 8605 Santa Monica Blvd., #46789, Los Angeles, CA, 90069-4109, (800) 669-8914, http://www.ayurvedanama.org/general/?type=CONTACT , http://www.ayurvedanama.org .

National Center for Complementary and Integrative Health (NCCIH), 9000 Rockville Pike, NIH Campus, Bldg. 31, Bethesda, MD, 20892, (888) 644-3615, https://nccih.nih.gov/tools/emailnccih , https://nccih.nih.gov .

Rebecca J. Frey, PhD

  This information is not a tool for self-diagnosis or a substitute for professional care.