This post is part of the “To Try or Not to Try” blog series. Written by a registered dietitian (RD) or dietetic intern, each post explores the claims and science surrounding a different dietary pattern or trend. After compiling this research, each RD or RD2be gave the diet a grade based on whether it appears to hold up to the hype. A = “yes, go for it!” and F = “no way, absolutely not!”
About the Author:
Theresa Gionta, RD grew up in southern Orange County and attended the Pennsylvania State University where she graduated with a Bachelor’s in Nutritional Sciences in 2015. She is a registered dietitian (RD) pursuing her passion in her current job counseling those with eating disorders. Feel free to connect with her on Instagram (https://www.instagram.com/theresagionta.rd/) and check out her blog “The Kale Cookie” (https://wordpress.com/view/kalecookie.wordpress.com).
What is it recommended for?
Juice detoxes are recommended on mainstream platforms to help “detox” the body, feel less bloated, and achieve quick weight loss. While the medical community does not widely promote juice detoxes, a liquid diet is often prescribed for pre- and post-bariatric surgery, pre-colonoscopy, and post-gastrointestinal surgery patients.
What foods are allowed?
The foods “allowed” on a juice detox are mainly fruits and vegetables, eliminating processed foods, caffeine, and alcohol.
What is the overall nutrient composition?
Juice detoxes typically contain a high sugar content, low fiber, and lack protein, fatty acids, and other essential nutrients. Carbohydrates supply all the calories, which are very minimal.
Are the claims supported by science?
One claim is that juice cleanses better provide all of the nutrients in fruits and vegetables, but as dietitians, we know that it is more beneficial to eat the whole fruit or vegetable because of the fiber content. Juice cleanses lack essential fiber needed for a healthy intestinal tract; therefore, bowel movements may slow down. If someone is not big on eating fruits and vegetables, this could be a viable option, but it is not preferred (1).
There is no scientific evidence to support the idea that juice detoxes clear toxins from the body any better than your body’s mechanisms. The primary function of the liver and kidneys is to filter and eliminate wastes from the body; therefore, a juice detox should not be necessary. Juice detoxes have not been proven to work in the long term and could be unsafe (2). They also do not appear to increase lifespan or improve health (3, 4). Possible dangers of juice detoxes include dehydration, depleted electrolytes, impaired bowel function, disruption of the intestinal flora, and metabolic acidosis (5).
Juice detoxes also change the composition of your gut microbiome. A study done by Luke Thompson, Ph.D. at CU Boulder found that cleanses do alter your gut microbiome, but once a regular diet is resumed the gut microbiota will return to its original state. Therefore, cleanses do not promote a healthy gut microbiota in the long-term (6).
Are there any possible hormonal disturbances?
Possible hormone disturbances that could occur with juice cleanses are as follows. Initially, the level of insulin drops and the levels of glucagon, epinephrine, and norepinephrine rise. When blood sugar drops, glucagon is signaled to release glucose from the liver and muscles to regulate blood sugar and adjust it to an appropriate level. Cortisol, epinephrine, and norepinephrine are released during starvation and in times of stress. Ghrelin (a hunger hormone) is produced in the gut when the body needs food and may decrease during a diet, causing hunger cues to depart.
Who should definitely not try this diet?
Given the above information, most people should not attempt a juice detox/cleanse. Specific populations that should definitely not try this dietary trend include:
- People with diabetes. The dramatic spikes in blood glucose associated with solely drinking juice can be detrimental to a diabetic’s health. In some cases, if blood sugar drops too low a few hours after drinking juice, it can lead to diabetic ketoacidosis (DKA). Consuming juice solely can be especially dangerous if a person with diabetes is on blood glucose-lowering medications.
- Athletes. This population has increased energy needs. Juice cleanses will not provide enough energy for an athlete to compete at their fullest potential and could lead to lightheadedness and fatigue.
- Pregnant women. Juice cleanses lack essential nutrients needed for fetal growth. Vitamins minerals required are vitamin D, Folic acid, calcium, vitamin C, thiamine, riboflavin, niacin, vitamin B12, vitamin E, Zinc, iron, and iodine.
- Children & adolescents. These populations need essential nutrients and energy to grow to their fullest and best potential. Bone growth is occurring in adolescent years, which requires adequate calcium. A juice cleanse is most likely deficient in calcium.
Is this diet realistic and sustainable?
Juice cleanses are not realistic and sustainable for long-term weight loss. In fact, they can lead to weight gain once regular diet resumes. When nutritionally deprived, the body goes into starvation mode: hunger signals stop, metabolism shuts down, and the body starts holding on to fat stores. Once a regular balanced diet resumes, the body likely will increase storage of adipose tissue to prepare for possible starvation. Also, depriving yourself can lead to bingeing, which can result in weight gain.
What are the overall pros and cons?
Overall, juice cleanses may initially make a person feel better about themselves for making healthy choices and can be a kick start for weight loss. On the contrary, juice detoxes are not proven to rid the body of toxins better than your body’s mechanisms, do not result in long-term weight loss, lack in essential nutrients, can lead to fatigue, and are not a realistic way to cleanse the body and lose weight.
What grade do you give this diet?
I would give this diet a grade of an F because of the lack of evidence to support positive health benefits. I believe that juice cleanses feed off people’s insecurities of wanting a quick way to lose weight. There is no such thing as a quick way to weight loss. The only way to achieve long-term weight loss is developing healthy eating habits that are realistic and sustainable for life.
What is your recommendation for an eating pattern for the average human?
My general recommendation for the average human’s healthy eating pattern is to develop a mindset that healthy eating is a lifestyle, not a “diet.” I am a strong advocate for intuitive eating, which is eating when you are hungry and stopping when you are full. There is no such thing as “good” or “bad” food. Food is food, and it all plays a vital role in maintaining daily body functions.
This content is intended for informational and educational purposes only. It is not intended as medical advice, medical nutrition therapy, or individualized nutrition counseling. Talk to your doctor or another licensed healthcare practitioner before making any changes to your diet, medications, or exercise routine. The opinions of these authors are their own and are not approved, sponsored, or endorsed by any professional organizations including but not limited to the Academy of Nutrition and Dietetics, United States Department of Agriculture, Food and Drug Administration, National Institutes of Health, American Heart Association, and American Diabetes Association.
“Juicing 101: Nutrition Tips for Consumers.” Juicing 101: Nutrition Tips for Consumers | Nutrition.gov, USDA, Food & Nutrition Information Center, http://www.nutrition.gov/subject/shopping-cooking-meal-planning/juicing-101.
Foroutan, MS, RDN, Robin. “What’s the Deal with Detox Diets?” Www.eatright.org, Academy of Nutrition and Dietetics, 26 Apr. 2017, http://www.eatright.org/resource/health/weight-loss/fad-diets/whats-the-deal-with-detox-diets.
Mineo, Harvard Staff Writer, Liz, et al. “Intermittent Fasting May Be Center of Increasing Lifespan.” Harvard Gazette, Harvard University, 6 Nov. 2017, news.harvard.edu/gazette/story/2017/11/intermittent-fasting-may-be-center-of-increasing-lifespan/?utm_source=twitter&utm_medium=social&utm_campaign=hu-twitter-general.
“‘Detoxes’ and ‘Cleanses.’” National Center for Complementary and Integrative Health, U.S. Department of Health and Human Services, 24 Sept. 2017, nccih.nih.gov/health/detoxes-cleanses.
“The Dubious Practice of Detox.” Harvard Health Publishing, Harvard Medical School, May 2008, http://www.health.harvard.edu/staying-healthy/the-dubious-practice-of-detox
Hyde, Embriette. “What Does a Three-Day Dietary Cleanse Do to Your Gut Microbiome?” American Gut, American Gut, 29 Feb. 2016, americangut.org/what-does-a-three-day-dietary-cleanse-do-to-your-gut-microbiome/.