Juice cleanses have surged in popularity as a quick way to lose weight and detoxify the body. These diets involve consuming only fruit and vegetable juices for a period ranging from one day to a week or more. While proponents claim numerous benefits, it's essential to understand the science behind juice cleanses and their potential risks.
What is a Juice Cleanse?
A juice cleanse is a diet where a person almost exclusively drinks fruit and vegetable juices for as long as 10 days or as short as just a day or two. This liquid-only diet often involves consuming only juices or homemade concoctions with water, lemon, and added spices. The aim is often weight loss or to clear toxins from the body.
Potential Benefits of Juice Cleanses
While the evidence supporting juice cleanses is largely anecdotal, some potential benefits exist:
Increased Nutrient Intake
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. For individuals who struggle to consume enough fruits and vegetables, juicing can be a way to increase their intake of essential nutrients. Juices also retain vitamins because they are raw.
Hydration
Many people don't drink enough water daily. Juice cleanses provide good hydration and may help prevent symptoms of dehydration, such as brain fog, irritability, and headaches.
Read also: Explore the pros and cons of fruit juice detoxes.
Short-Term Weight Loss
Juice cleanses may lead to short-term weight loss due to calorie restriction. A study found that a 3-day juice-only diet altered gut bacteria and led to lasting weight loss. Researchers suggested that changes in gut bacteria played a role, but it's worth noting that the study participants consumed only 1,310 calories per day. Calorie deficits often lead to weight loss, so the weight loss may just be due to cutting calories. The study was also very small, including just 20 people, so more research is needed to draw conclusions about juice cleanses and weight loss.
Gut Bacteria Changes
Proponents claim that juice cleanses can alter a person’s gut bacteria. A 2017 study showed that 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.
Kidney Health
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.
Risks and Downsides of Juice Cleanses
Despite the potential benefits, there are several downsides to consider:
Lack of Fiber
Juicing fruits and vegetables removes the fiber, so we miss out on its benefits, like helping to regulate blood sugar, manage cholesterol, and support gut health. Fiber is stripped out of fruits and vegetables during the juicing process. The absence of fiber can lead to undesirable side effects. Fiber is important for your digestive health, helps regulate blood sugar and cholesterol, and contributes to feelings of fullness. Fiber also fuels good gut bacteria that fight inflammation. A balance of fiber and sugar is important to your health. Without fiber, sugar-loving bacteria can multiply, and juice has a high concentration of sugar per serving.
Read also: Juice Cleanse: Benefits and Risks
Nutrient Imbalance
Juices lack other nutrients like protein, whole grains, and heart-healthy fats. 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.
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. Not only is rapid weight loss unhealthy, but it doesn't last. The weight loss you may see is mostly due to the lack of food in your GI tract and the loss of muscle experienced during a juice cleanse.
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.
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.
Kidney Problems
Anyone with kidney disease should not undergo a juice cleanse. 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.
Read also: Renal Diet Guide: Navigating Orange Juice Consumption
Disrupted Gut Health
Recent research suggests that juicing may mess with the microbiome. A Northwestern study compared three diet groups: those who drank fruit juice only, those who consumed juice with solid foods, and those who ate whole plant-based foods. The group that did a 3-day juice cleanse showed the most harmful gut bacteria changes linked to inflammation, while the group that ate whole foods saw more beneficial shifts. The juice-plus-food group had milder effects.
Potential for Eating Disorders
Juicing may increase the 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.
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.
Juice Cleanses and Detoxification
Advocates of juice cleanses often claim that the programs can help remove toxins from a person’s system. However, the concept of detoxing by eating or drinking certain diets is a myth. The liver and kidneys remove toxins and waste. 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, there is insufficient evidence to suggest that juice cleanses or other detoxification diets impact the ability to remove toxins. All you need to do to support these organs is maintain a well-balanced diet and be mindful of excess alcohol and added sugars.
Alternatives to Juice Cleanses
There is insufficient evidence to assess the efficacy of 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. Instead, focus on eating whole foods, including veggies, fruits, beans, nuts, and whole grains.
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.
Smoothies
One delicious way to get the potential benefits of juicing, plus the natural fiber from these foods, is to enjoy fruits and veggies in smoothie form. Blend your favorite fruits and veggies with some Greek yogurt or soy milk for protein. For a green smoothie, pair kale or spinach with a frozen banana.
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.
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.