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What are 7-day juice cleanses good for?

Juice cleanses have become increasingly popular in recent years as a way to detox, lose weight quickly, and “reset” your diet. Typically lasting 3-10 days, juice cleanses involve consuming nothing but fresh fruit and vegetable juices. Proponents claim they help eliminate toxins, improve digestion, increase energy, aid weight loss, and more. But are these touted benefits backed by science? Let’s take a closer look at what 7-day juice cleanses are all about.

What is a 7-day juice cleanse?

A juice cleanse is a type of diet that involves drinking only fresh fruit and vegetable juices for a set period of time, usually from 3-10 days. On a standard 7-day juice cleanse you would consume nothing but cold-pressed juices made from produce like kale, spinach, celery, cucumber, carrot, apple, beet, ginger, lemon, etc. Most juice cleanse programs provide pre-made juices that are delivered to your door each day. The juices are designed to provide a range of vitamins, minerals and phytonutrients while being low in calories. A day’s worth of juice on a cleanse usually works out to around 1,000-1,200 calories.

In addition to the juices, some cleanse programs allow herbal teas, water and broths. But all solid foods are eliminated during the cleanse period. The goal is to give your digestive system a rest while flooding your body with nutrients from produce thought to have detoxifying properties. Proponents claim this can help remove toxins, improve digestion and gut health, boost immunity and more.

Purported benefits of a 7-day juice cleanse

Why do people opt to go on a juice cleanse? Here are some of the touted benefits:

  • Detoxification – By abstaining from solid food for a week while drinking antioxidant-rich juices, cleansers aim to flush out bodily toxins.
  • Weight loss – Not consuming any solid foods for a week generally leads to weight loss, but much of it is water weight that is often regained.
  • Resting the digestive system – With no food to digest, cleansers give their GI tract a break.
  • Increased energy – With the body temporarily relieved of the work of digestion, some people report feeling more energetic.
  • Improved immunity – Fresh produce provides vitamin C, antioxidants and phytochemicals to support immunity.
  • Improved skin, hair and nails – Nutrients like vitamin A and vitamin C support healthy skin and nails.
  • Elimination of cravings – Abstaining from junk foods can help reset unhealthy cravings.
  • Preventing chronic disease – The nutrients in juice may help protect against chronic illnesses.

What does the science say about these purported benefits?

While a juice cleanse may sound intuitively like a good idea for “purifying” your body, there is limited scientific evidence to support many of its claims. Here is what researchers have found so far regarding the purported benefits:

Benefit What the Science Says
Detoxification The body already has highly efficient systems for cleansing itself through the liver, kidneys and gastrointestinal tract. There is no evidence that juice cleanses enhance toxin elimination above normal functioning.
Weight loss Cleanses lead to temporary water weight loss. Effects on fat loss are mixed. Some studies show minor decreases in body fat percentage but lean tissue is often lost as well.
Resting digestion This claim is likely true since no solid foods need digesting. But whether this provides long term digestive benefits is unknown.
Increased energy While some people report feeling more energetic during a cleanse, others report fatigue, headaches and weakness as the body adapts to the very low calorie intake.
Improved immunity Juices provide beneficial vitamins and antioxidants but there is no evidence this boosts immunity more than a normally healthy diet.
Improved skin, hair and nails The high vitamin content may temporarily improve appearance but these effects reverse without sustained intake of micronutrients.
Elimination of cravings Cravings are reduced during the cleanse period but often return once normal eating resumes. No long term benefit.
Preventing chronic disease No evidence that short term cleansing prevents disease. Long term diet changes would be required.

Potential dangers of 7-day juice cleanses

While juice cleanses are unlikely to be harmful for most people for a short period of time, there are some potential dangers to be aware of:

  • Nutrient deficiencies – Lacking protein, fat, carbs and other nutrients for days can lead to deficiencies over time.
  • Blood sugar spikes – Juices high in fruit can spike blood sugar and insulin in unhealthy ways for diabetics.
  • Muscle loss – With inadequate protein intake, cleanses may lead to loss of lean muscle mass.
  • Metabolism slowdown – Severely restricting calories can cause the metabolism to slow down as the body tries to conserve energy.
  • Electrolyte imbalance – Laxative and diuretic effects can lead to electrolyte problems.
  • Headaches – Caffeine withdrawal and low blood sugar can trigger headaches.
  • Fatigue – Low energy intake and lost electrolytes can cause fatigue.
  • Hunger – Cleanses require ignoring hunger cues, which some struggle with.
  • Binges – Post-cleanse binge eating is common as the body seeks calorie replenishment.

Who should not do a juice cleanse?

Given the restrictive nature of juice cleanses, they are not recommended for everyone. The following groups should avoid embarking on a 7-day liquid diet:

  • Children or teenagers
  • Pregnant or breastfeeding women
  • Anyone with diabetes or blood sugar problems
  • Individuals with eating disorders or disordered eating tendencies
  • People with gastrointestinal issues
  • Anyone who is underweight or malnourished
  • People with kidney disease or no kidneys
  • Individuals with nutrient deficiencies
  • Those with caffeine withdrawal sensitivities
  • Anyone currently taking prescription medications, especially diabetes or blood thinner medications

For those with medical conditions, it’s best to discuss doing a cleanse with your doctor first to avoid complications. Otherwise, pay attention to your body and stop if you experience any concerning symptoms like fatigue, headaches or hunger pains.

Tips for completing a 7-day juice cleanse

If you want to try out a juice cleanse, here are some tips to help you succeed:

  • Ease into it – Cut back on caffeine, sugar, alcohol and processed foods a few days beforehand.
  • Stock up on allowed teas/broths – Variety helps beat boredom.
  • Plan your schedule – Cleanses require more time to juice and clean.
  • Listen to your body – Stop immediately if you feel unwell or have intense hunger.
  • Stay hydrated – Drink plenty of water in addition to juices.
  • Manage activities – Nothing too strenuous since calories are low.
  • Supplement if needed – If headaches strike, drink bouillon for sodium/potassium.
  • Transition afterward – Reintroduce foods gradually starting with fruits and veggies.

The bottom line on 7-day juice cleanses

While the radical restriction of juice cleanses rarely stands up to science, short-term juice fasts are unlikely to be harmful for most healthy individuals. Some people do report feeling better and losing some weight in the process. However, research shows the weight loss to be temporary and largely due to water and muscle mass rather than fat.

If you are looking to juice cleanse, be mindful of health risks, prepare properly and don’t expect miracles. And be sure to consult your healthcare provider before undergoing a dramatic diet change like a multi-day juice fast, especially if you take medications or have any medical conditions.

At the end of the day, know that your body is already equipped to detoxify itself through its normal bodily processes. Focusing on a balanced, whole food diet rich in plants, fiber, healthy fats, lean proteins and probiotics is likely a better strategy for supporting lasting health and wellness.