It is important to note that there are differences between juicing and blending:
- Juicing involves squeezing the juices from fruits and vegetables and separating them from the pulp.
- Blending mixes all of the edible parts of fruits and vegetables, including the pulp, or fibrous portion.
Potential benefits
Juice cleanses usually involve consuming only juice for a certain period, which typically ranges from 3 to 10 days.
The advocates of juicing say that it offers people many benefits, which may include those below:
- Fruits and vegetables are high in vitamins and minerals. Drinking juices could introduce extra nutrients into the body to boost overall health.
- Juices are rich in anti-inflammatory compounds that may boost the immune system and help a person feel more energetic.
- The creators of many juicing plans market the ability of their juices to flush toxins from the body, although they rarely specify which toxins the juices remove.
- Juices could help improve digestion by introducing healthy enzymes that make the gut work more efficiently.
However, most of these potential benefits are anecdotal, meaning that they do not have scientific proof to support them.
Potential risks
Doctors have identified several risks of juice cleanses, including those below:
- Drinking large quantities of juice may be harmful to those with kidney disorders. Certain types of juice contain oxalate, an acid that can contribute to kidney stones and other kidney problems.
- Cleansing diets are usually low in calories. A reduced calorie intake may result in temporary weight loss, but this change is rarely long-lasting.
- If a person consumes juices that are unpasteurized or have not had another treatment to remove bacteria, they are at greater risk of illness. This is especially true for very young and older people as well as those with weakened immune systems.
- If a juice cleanse includes laxatives or other methods of bowel stimulation, a person could lose too many nutrients in their stool. This can lead to dehydration and imbalanced electrolytes.
- Consuming an insufficient number of calories can cause a person to experience symptoms relating to low blood sugar because the body does not have enough energy. Examples of these symptoms include fainting, weakness, dehydration, headaches, and hunger.
A person should also be wary of pre-packaged juice cleanses that promise significant results, such as reversing diseases or providing dramatic health benefits. There is usually a lack of research to support these claims.
What effects could a juice cleanse have on the body?
To date, there has not been much research on the possible benefits of juice cleanses. However, researchers have investigated the factors below:
Weight loss and gut bacteria changes
In one study published in Scientific Reports, researchers asked 20 healthy participants to consume only six bottles of different juices a day for 3 days. The juices contained a variety of ingredients, such as greens, apples, cucumbers, lemon, cayenne pepper, and vanilla bean.
The participants lost an average of 1.7 kilograms (kg), or 3.75 pounds (lb), after the fast. At a follow-up 2 weeks later, their weight remained 0.91 kg, or 2.01 lb, lower on average.
The participants did not report increased well-being levels at the end of the 3 days, but they felt that these levels were higher 2 weeks after the cleanse.
The researchers also found that the juice cleanse increased the amounts of some health-promoting bacteria and lowered the number of bacteria that cause illness.
Kidney health
A case report suggests that juice cleansing could carry the risk of kidney damage.
The report looked at a patient who experienced kidney failure after participating in a juice fast for 6 weeks. The patient kept a detailed journal of the juices that he consumed, which showed that he had an estimated daily intake of 1,260 milligrams (mg) of oxalate.
Oxalate is an organic acid that occurs naturally in many plants. It is also a nephrotoxin, meaning that larger quantities of it can be damaging to the kidneys.
The authors recommend that people who choose to follow a juicing program calculate how much oxalate they are likely to consume each day.
How to do a juice cleanse
Juice cleanse supporters may recommend different types of juice cleanse, such as:
- drinking only juices and liquids for several days
- consuming juices in combination with dietary supplements
- combining juices with procedures that “cleanse” the colon, such as enemas or colonic irrigation
- drinking juices alongside specific diets as a means of promoting weight loss
Examples of some of the juice blends that the Scientific Reports study used include:
- apple, cucumber, celery, romaine lettuce, lemon, spinach, kale, and parsley
- or apple, lemon, ginger, and beet
- or apple, pineapple, lemon, and mint
- filtered water, cayenne, lemon, almonds, dates, sea salt, and vanilla bean
Drinking six of these juice combinations daily provided an intake of 1,310 calories per day.
Summary
Juice cleanses are a controversial topic within the medical community because they do not usually offer long-term solutions for weight loss or wellness. Most experts will recommend a balanced, healthful diet instead.
The evidence to support the possible benefits of juicing tends to be anecdotal. There appears to be more evidence to suggest that a juice cleanse can have a negative impact on the body, for example, by reducing kidney function.
Before starting a juice cleanse, people should speak to their doctor to ensure that they do not need to amend their juicing plan in any way to protect their overall health.