Juicing and juice fasts are all the rage right now! You may have seen juice bars popping up left and right in your neighborhood, or read about how Beyonce lost 20 pounds in 2 weeks by following a juice diet.
Many people opt to try juice cleansing or fasting as a way to change their diet’s status quo with hopes of jump-starting their way toward better health, weight loss, and improved gut health. But is following this liquid diet effective or even safe?
In this article, we’ll unpack everything you need to know about the benefits and side effects of juice fasting and the safest way to do it.
What is A Juice Fast?
A juice cleanse is a type of diet that involves consuming only juices from vegetables and fruits in an attempt to lose weight and detoxify the body. Juice cleanses usually involve consuming only juice for a certain period, which typically ranges from 3 to 10 days.
Juicing methods vary, from squeezing fruit by hand to motor-driven juicers. Two common types of juicers include:
- Centrifugal: These juicers grind fruits and vegetables into pulp through a high-speed spinning action with a cutting blade. The spinning also separates the juice from the solids.
- Cold-press: Also called masticating juicers, these crush and press fruits and vegetables much more slowly to obtain as much juice as possible.
The nutritional quality of juice obtained from centrifugal and cold-press juicers is similar (1).
It is also 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.
As these cleanses are restrictive in terms of food groups and calories, many people are skeptical about their possible benefits.
What Are the Potential Benefits of Juice Fasting?
The advocates of juicing say that it offers people many benefits, which may include those below:
1. It Detoxifies Cells and Tissues
Unfortunately, there has been little evidence to support the entire ‘detox’ concept underlying juice fasts.
According to a 2014 review published in the Journal of Human Nutrition and Dietetics, the few studies that demonstrated a correlation between toxin elimination and detox diets all suffer from flawed research designs and, therefore, cannot provide conclusive results (2).
Also, to date, all clinical trials have been conducted on animals and not on humans. You cannot always draw parallels between the results of studies performed on them and us.
2. It Helps Prevent Chronic Diseases
The current scientific literature seems stacked against juice fasts. Current studies show mixed results.
In a 2018 study, researchers found that drinking up to seven glasses of fruit juice can significantly reduce the risk of coronary heart disease and cardiovascular disease (3). Additionally, participants who consumed either one to four glasses, or four to eight glasses, had a lower risk of stroke.
Another smaller study, conducted in 2017 supports the findings above. This particular study highlighted that a three-day juice cleanses increased nitric oxide levels and decreased lipid oxidation, which can both lead to improved cardiovascular health (4).
However, a 2019 study directly contradicts both studies’ findings above. In this study, the researchers note that each additional daily serving of fruit juice increases all-cause mortality risk by a whopping 24% (5)!
Worryingly, according to a 2013 case report, juice fasting could carry the risk of kidney damage (6). The report detailed a patient who’d experienced kidney failure after participating in a juice cleanse for six weeks.
While more research is needed, current scientific literature suggests that short fasts, lasting no longer than one week may improve overall health.
3. It Aids in Weight Loss and Gut Health
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 after the fast. At a follow-up 2 weeks later, their weight remained 0.91 kg lower on average (7).
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.
4. It’s Nutritious
Juice is one of the easiest ways to obtain more nutrients! Nutrient levels in the foods you eat are also much lower than they used to be. This is largely due to processing methods and the time it takes to get produce from the field to the supermarket (8).
Fruits and vegetables are full of vitamins, minerals, antioxidants, and plant compounds that may protect against disease (9, 10).
If you find it difficult to get the recommended amount of fruits and vegetables into your diet each day, juicing can be a convenient way to increase your intake.
Evidence showed that supplementing with mixed fruit and vegetable juice over 14 weeks improved participants’ nutrient levels of beta carotene, vitamin C, vitamin E, selenium, and folate (11).
Furthermore, a review of 22 studies found that drinking juice made from fresh fruits and vegetables or blended powder concentrate improved folate and antioxidant levels, including beta carotene, vitamin C, and vitamin E (12).
What Are the Possible Risks of Juice Fasting?
Aside from the risk of developing kidney damage, there are quite a few more side effects of juice fasting and cleansing, especially if a cleanse consists of fruit-only juices.
Headaches and Fatigue
Juices are higher in sugar and lower in fiber than whole foods, leading to a greater likelihood of spikes and dips in blood sugar. Some people say that headaches from juice fasting are due to the toxins leaving your body, but fluctuating blood sugar, in addition to the lower energy intake from the lack of protein and fat in the juices, are actually the root causes of headaches and fatigue.
Social Isolation
Think about it, if you’re wanting to do a longer juice cleanse of 10 days or so, that’s 10 days when you’ll be going to lunch with co-workers and won’t be able to eat. That could be multiple dinners out when you can only sip on water.
Expensive
Juice fasts can be quite expensive, especially if you buy a pre-formulated cleanse. A three-day juice cleanse will often run you anywhere between one to two hundred dollars. That would probably buy you two weeks’ worth of groceries!
Hard to Maintain
All of these factors make juice fasts hard to maintain, even for just a day. And for some people, juice fasts can encourage a type of restrictive eating that may promote an unhealthy relationship with food.
How to Do A Juice Fast?
Before Juice Fast
Preparation is the first step to enjoying a great juice cleanse!
You can maximize the benefits of your next cleanse by dedicating a few days to preparation. Plus, you’ll enjoy a more pleasant experience and avoid a potential “healing crisis” by cleaning up your diet in the days leading up to your juice cleanse.
Most experts would recommend you to pre-cleanse for 2-7 days depending upon your current eating habits and lifestyle.
- If you are a health enthusiast who is off your “usual” track and needs a reset to get back to your norm of clean eating, 1-2 days is likely enough time to set you up for great success. If kale is a regular part of your diet and you wouldn’t be caught consuming high fructose corn syrup, this is you!
- If you eat well most days, indulge a bit on the weekends and are looking for a solution to make consistently healthy choices. Before diving into your juice cleanse, spend 3-4 days in your pre-cleanse elimination phase to rid your body of remnants of too much caffeine, alcohol or processed foods.
- Maybe too much to do in too little time leaves you regularly eating a Standard American Diet (SAD) consisting of processed or pre-packaged food, and not enough fresh, nutrient dense plant-based foods. To avoid potential unpleasant detox symptoms, commit to 5 days of a pre-cleanse diet.
- Is indulging in fast food, sugary sweets, and sodas on the regular sound like you? Let your energy levels, metabolism, attitude and digestive system experience a reset so you can live your healthiest and happiest life. We recommend that you embark on a 7-day pre-cleanse phase to reduce potential detox symptoms and prepare your taste buds for your cleansing journey!
After knowing how long you should pre-cleanse, what should you be doing as part of your pre-cleanse regimen? Here are some tips:
Drink More Water
Cleansing reconnects you with your body’s needs. Dehydration is commonly mistaken for hunger, so drink more water to keep your cells hydrated and eliminate false hunger. Drinking water is also an important first step in preparing for your juice cleanse because it transports nutrients to your cells.
Cut Back on Caffeine
For best results while cleansing, we want to bring your body into a more alkaline state.
If you typically enjoy coffee or drink soda, take measures to wean off of these highly acidic, caffeinated beverages before your cleanse.
For coffee-lovers, if cutting coffee out of your diet is not a personal goal, it is not essential to completely eliminate it during your cleanse. As a solution, you may opt to drink a low-acid, cold-brew coffee, choose to transition to a matcha green tea as a way to still get a bit of caffeine without disrupting your alkalinity levels.
Eat and Drink More Fruits and Veggies
Up your enzyme intake and start introducing more fruits and vegetables into your routine by including at least a few servings of raw fruits and vegetables into your diet now!
Avoid Animal Products
In the 1-2 days before your fasting begins, aim to eat a strictly plant-based diet. Do not eat meat, eggs, or dairy products.
If you typically eat more than one serving of animal products per day, try to cut that down in the week before your cleanse. Animal products place a higher demand on your digestive system than plant-based foods do. It is ideal to begin easing the burden on your digestive system so that it’s ready to kick into high gear once you begin your juice fast.
Eliminate Processed Foods
The sooner that you can eliminate processed foods from your diet, the better. READ THE LABELS ON ALL YOUR FOOD.
If you can’t pronounce the ingredient or don’t know what it is, chances are your body won’t know what to do with it either and you are adding to your toxic burden. Be careful of junk that is disguised as health food with labels like “natural” and other trick marketing buzzwords.
EAT ORGANIC WHENEVER POSSIBLE!
During Juice Fast
Drink As Much Juice As You Can
During a juice fast, you should aim to drink at least six 16-ounce servings of juice. That works out to one serving of juice every two hours from 8 a.m. to 6 p.m. You can also drink as much water and herbal tea as you want throughout the day. Adding one or two more servings per day is acceptable if you feel like you need more sustenance. This amount of juice is necessary to get enough calories so you are still your body’s basic energy requirements.
Make Your Juice with Mostly Veggies
Aim to make most juices 80% veggies. That means 13 out of 16 ounces (or at least 1.5 out of 2 cups) of juice should be from vegetables.
- Good veggies to include are spinach, kale, cucumber, zucchini, carrots, beets, and celery.
- Always use lemons, limes, blackberries, raspberries, blueberries, dark cherries, and kiwis. These fruits have lower sugar content and are loaded with anti-inflammatory antioxidants.
For a boost of flavor, also consider adding in nutrient-packed herbs such as ginger root, turmeric root, basil, parsley, cilantro, and mint.
You May Add Some Solids
For a little more staying power, some people like to add in something with a bit of fat and/or protein. If you find yourself super hungry, consider including one serving of homemade cashew milk per day of your cleanse. You can also make one of your juices a smoothie instead or include a serving of celery and nut butter. There’s nothing wrong with adapting your juice fast to meet your needs.
Avoid Strenuous Exercises
It would be a good idea to not participate in any strenuous physical activity like HIIT during a juice fast, as you could become dizzy and fatigued more easily. If you are constantly feeling tired, loopy, unable to concentrate, or your hunger pangs are taking over, it may be a sign that your juice fast is doing more harm than good. At this point, consider returning to a whole food diet.
Stop After 3 Days
Experts say that it is completely safe for healthy people to participate in a juice fast for up to three days and then return to a regular diet. Doing a juice fast for a longer period of time can increase the likelihood of experiencing the negative side effects of juicing such as headaches, hunger, and blood sugar swings, and there is no proof of benefit of increased “detoxification” with a longer fast.
After Juice Fast
The first day after juice fasting, try eating smaller meals and snacks throughout the day, as a large meal might make you feel nauseated and uncomfortable. Salads, oatmeal, sweet potatoes, and whole fruits could help ease you back into solid foods again, but if you don’t have a sensitive stomach, you may be able to resume eating your normal diet right away.
After this short introductory period back to solid foods, it is important to incorporate high-quality nutritious foods back into the diet. Whole fruits and vegetables will add more fiber back into your diet. Whole grains like brown rice and quinoa, and protein-rich foods like lentils, legumes, and high-quality meats and poultry should also be added back to meals and snacks.
Who Is It For?
Juice fasting is not for everyone! While most healthy people can give it a try, there are several groups of people who should NOT participate in juice fasting. Children, adolescents, and pregnant and breastfeeding women need adequate amounts of energy and protein for growth, and juice fasting would not meet those needs.
Elite and competitive athletes also have very high calorie needs, and juice fasting would not support that high energy expenditure or contain the nutrients necessary for optimal recovery.
Lastly, people with diabetes, kidney disease, or liver disease should steer clear of juice fasting because of having an altered physiological response to food.
The Bottomline
Juice fasting and cleansing are essentially trendy, fad diets, and most of the reported health benefits of juice fasting are not backed by science. There are better and safer alternatives to juice fasting, like just adding more fruits and vegetables to your daily diet. However, if you really want to try a juice fast or cleanse, keep the tips above in mind to minimize the potential side effects!
References:
(1) https://pubmed.ncbi.nlm.nih.gov/31286079/
(2) https://onlinelibrary.wiley.com/doi/full/10.1111/jhn.12286
(3) https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/pure-fruit-juice-and-fruit-consumption-and-the-risk-of-cvd-the-european-prospective-investigation-into-cancer-and-nutritionnetherlands-epicnl-study/BC762A823262D074D07CD369CBB9005C
(4) https://www.nature.com/articles/s41598-017-02200-6
(5) https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2733424
(6) https://www.amjmed.com/article/S0002-9343(13)00390-2/fulltext
(7) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5438379/
(8) http://bfff.co.uk/wp-content/uploads/2013/09/Leatherhead-Chester-Antioxidant-Reports-2013.pdf
(9) https://pubmed.ncbi.nlm.nih.gov/21862744/
(10) https://pubmed.ncbi.nlm.nih.gov/15678717/
(11) https://pubmed.ncbi.nlm.nih.gov/15190044/
(12) https://pubmed.ncbi.nlm.nih.gov/22081614/
