Juice cleanses have become a popular trend, with advocates claiming they offer a quick and easy way to lose weight, clear toxins from the body, and improve skin condition. A juice cleanse is a type of short-term detox diet that involves consuming only juices from fruits and vegetables. However, there is very little research to support these purported benefits, and there may even be risks associated with juice cleansing.
What is a Juice Cleanse?
A juice cleanse is a liquid-only diet that typically lasts from one to ten days, where all meals are replaced with fruit and vegetable juices, sometimes combined with water, lemon, and spices. The intention behind juice cleanses is often weight loss or the removal of toxins from the body.
Potential Benefits of Juice Cleansing
Advocates of juice cleanses claim that they can help remove toxins from a person’s body and aid in weight loss. Proponents also claim that juice cleanses can alter a person’s gut bacteria. Fruit and vegetable juices are high in nutrients and can play a crucial role in balanced diets. Juicing may also give the digestive system a rest from digesting fiber, which may help some people who have certain health conditions or who receive certain medical treatments.
Let's look at some of the potential health benefits of juice cleanses.
Juicing for Health
Fruits and vegetables are high in various active compounds that benefit general health and help prevent chronic conditions. For example, they’re a good source of phenolic compounds, which have antioxidant, immune-supporting, and antibacterial properties. Fruit juices may also help lower blood pressure and cholesterol levels. Studies have shown that fruit and vegetable juices can boost levels of important vitamins and antioxidants, including folate, vitamin C, vitamin E, and beta carotene.
Read also: Explore the pros and cons of fruit juice detoxes.
Juicing for Weight Loss
Juice cleanses may help increase the number of healthy bacteria in your gut, which has been linked to weight loss. In a 2017 study, a 3-day juice-only diet altered the gut bacteria in 20 healthy adult participants. They experienced substantial weight losses that lasted after the study ended. The researchers concluded this may be due to changes in the participants’ gut bacteria. However, it’s important to note that the participants only consumed 1,310 calories per day. This is below the number of daily calories recommended by the “Dietary Guidelines for Americans 2020-2025” for weight maintenance, which is at least 1,600 calories for adult females and 2,000 for adult males. As such, being in a calorie deficit could lead to rapid weight loss.
However, a 2017 review found that while juice cleanses may cause initial weight loss due to calorie restriction, they will lead to overall weight gain once a person resumes a full, healthful diet. Studies also show that weight loss from juice-based diets may be “physiologically harmful” to participants. Researchers have also observed links between liquid diet trends and eating disorders.
Juicing to ‘Detox’
Some detox treatments have been shown to improve liver detoxification and remove environmental pollutants from the body. An increase in fluid consumption can help kidney function, and some nutritional compounds may help in the removal of non-organic waste products in the body. However, the authors of a 2015 review suggest that these clinical studies have significant flaws in methodology and low participant numbers. Much of the promoted evidence also comes from animal research, which can’t necessarily be applied to humans. There is insufficient evidence to suggest that juice cleanses or other detoxification diets impact the ability to remove toxins. The liver and kidneys naturally handle waste removal without needing a cleanse.
Juicing for Skin Health
Juicing may improve skin health. However, more studies with humans are needed before any conclusions can be drawn.
Hydration
Juice cleanses provide good hydration and may help prevent symptoms of dehydration, such as brain fog, irritability, and headaches.
Read also: Juice Cleanse: Benefits and Risks
Risks and Considerations of Juice Cleansing
Despite the claims made by proponents, juice cleanses are controversial in the medical community because they do not usually offer long-term weight loss or wellness solutions. There are several risks linked to juice cleanses, and there is insufficient evidence to assess their efficacy.
Lack of Scientific Evidence
There is a lack of scientific evidence to support the effectiveness of juice cleanses. Despite claims about detoxification, very limited scientific evidence supports juice cleanses. The body already has an efficient detox system - the liver and kidneys - that filters toxins from the body, deeming any extra "cleansing" unnecessary. While some studies suggest short-term benefits, there’s little proof that juice cleanses provide lasting health improvements. What's more, we currently don't have solid research on detox programs' long-term effects.
Nutritional Deficiencies and Side Effects
Most people who do juice cleanses don’t eat enough solid food to meet their energy needs. This may lead to increased hunger and energy restrictions that could cause symptoms like tiredness, headaches, and irritability. Juices also have less dietary fiber than whole fruits and vegetables. Some research suggests that less fiber facilitates your body to process and absorb the juice’s nutrients. However, dietary fiber also has many health benefits. It promotes blood sugar management, heart health, and gut health and is associated with a reduced risk of developing colorectal cancer. Fiber is stripped out of fruits and vegetables during the juicing process, causing undesirable side effects. It may lead to muscle and bone loss.
Blood Sugar Spikes
Many juices contain high amounts of natural sugars from fruits. Without fiber to slow digestion, sugar enters the bloodstream quickly, causing glucose levels to spike and then crash. This can lead to dizziness, fatigue, and irritability, especially for people with diabetes or insulin resistance.
Potential Kidney Problems
Many fruits and vegetables are rich in nutrients that can assist in the good working of the kidneys. Increasing fluid consumption can also be beneficial for kidney function. However, some foods are high in oxalate, a compound that can increase a person’s risk of kidney problems when consumed in high quantities. Foods high in oxalate include spinach and beets. People living with chronic kidney disease may be at risk of oxalate nephropathy. In rare cases, healthy people may also be at risk of this. Oxalate nephropathy is a condition in which the body cannot excrete enough oxalate through urine, causing it to build up in kidney tissue. In rare cases, this can cause kidney failure. Anyone with kidney disease should not undergo a juice cleanse.
Read also: Renal Diet Guide: Navigating Orange Juice Consumption
Risks of Juice Cleansing
Research has linked liquid diets with an increased risk of serious health complications and eating disorders. Juice cleanses don't give you enough nutrition and are linked with other health risks too. Juicing strips away much of the fiber in whole fruits and vegetables, which feeds beneficial bacteria that produce anti-inflammatory compounds such as butyrate. Without fiber, sugar-loving bacteria can multiply. The high sugar content in juice further fuels these harmful bacteria, disrupting the gut and oral microbiome.
Other Risks
Other risks associated with juice cleanses include:
- Unsustainable weight loss: Severe caloric restriction is not sustainable for most people and rarely leads to long-term weight loss. It may also increase a person’s risk of other complications. In most cases, a person will return to their starting weight quickly once caloric restriction ends.
- Low blood sugar: Consuming an insufficient number of calories can cause a person to experience symptoms relating to low blood sugar, including fainting, weakness, dehydration, headaches, and hunger.
- Malnutrition: A person on a juice cleanse may not consume enough proteins or fats. Both of these are crucial to physical health, healing, and brain function. Eliminating food groups for extended periods may also lead to malnourishment.
- Dehydration: 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.
- Increased risk of eating disorders: For example, an obsessive preoccupation with health-promoting foods and an avoidance of foods considered “less healthy” can lead to orthorexia nervosa.
How to Do a Juice Cleanse Safely
If you're still keen on trying a juice cleanse, take a few precautions to help avoid fatigue, blood sugar crashes, or nutrient deficiencies. If you have any health conditions, always check with a healthcare professional, like a dietitian, before starting. Juice cleanses aren’t for everyone, especially those with health conditions such as diabetes, digestive disorders, or nutrient deficiencies. A person should only adhere to juice cleanses or restricted liquid diets under medical supervision.
Here are some tips to keep a juice fast safe and balanced:
- Keep it short: Stick to a cleanse of one to three days. Longer cleanses can lead to low energy, irritability, and hunger. Your body doesn’t need weeks of liquid-only meals to "reset."
- Choose low-sugar juices: To avoid blood sugar spikes, go for juices with plenty of veggies and some fiber. Many juices made for juice cleanses contain natural sugars from the fruit, but you'll also want to check the nutrition facts label and avoid juices that contain added sugar.
- Don’t skip protein and fiber: Add small amounts of plant-based protein (like vegan protein powder) and fiber (like blended veggies) to keep your energy stable and support digestion.
- Listen to your body: If you feel dizzy, weak, or extremely hungry, it’s OK to quit. Eating nutrient-dense whole foods - like nuts, avocados, veggies, and lean proteins such as fish and poultry - can help you feel better.
Alternatives to Juice Cleanses
Someone wishing to lose or maintain a healthy weight and support their body’s natural processes can try the following alternatives:
- Balanced diet: Eating a balanced diet and staying adequately hydrated are the best ways to maintain a healthy weight and support the body’s removal of toxins.
- Plant-based diets: Based on minimally processed foods, these diets are naturally rich in fruit and vegetables and are associated with reduced body weight. With good planning, a plant-based diet can provide all the nutrients necessary for good health.
- Intermittent fasting: This involves abstaining from eating for limited periods and eating a regular diet at other times. Reviews have linked intermittent fasting with weight loss and improvements in insulin sensitivity.