Most people today know, or at least have heard, that fruits and vegetables are an essential part of a healthy diet. It’s why the USDA recommends that American adults eat one and half to 2 cups of fruit each day as well as 2 to 3 cups of vegetables. Fruits and vegetables are loaded with natural chemicals that act as potent antioxidants to help the body fight inflammation and help reduce the risk of chronic diseases. That’s the primary reason for the popularity of so-called “Juice Cleanses” which advocates say puts these chemicals to work to rid the body of toxins and helps you lose weight. But do they really work? And what should you be concerned about if you decide to do one? Let’s take a look at some juice cleanse benefits and weigh them against possible health risks.
What exactly is a juice cleanse?
A juice cleanse, also known as a juice fast, is a time-limited diet where the only thing you take in is the juice of fresh fruits and vegetables. In a classic cleanse (between three and seven days) you avoid all solid foods, dairy, caffeine, alcohol and added sugars but may add bone broth, veggie broth, herbal teas or electrolyte water to stay nourished and keep your blood sugar stable. There are dozens of commercial juice cleanse products on the market, but purists usually prefer to do their own juicing from locally sourced fresh fruits and vegetables. Typical fruits used in cleanses include apple, lemon, pineapple, orange, watermelon, grapefruit, berries, and pears. The most common vegetables juiced for a cleanse are celery, cucumber, beet, spinach, kale, ginger, turmeric, parsley and other leafy greens. Is juicing good for you? “That depends on how you define ‘good for you’,” according to Dr. Charles Berk, a Family Physician practicing in Brooklyn, New York. “The metrics haven’t really been defined very well, so, ‘good for you’ as an overall statement doesn’t quite mean as much as ‘bad for you’.”
What happens to your body during a juice cleanse?
Everyone is different so it’s always recommended that any juice cleanse be done under medical supervision.
Days 1-2: The Adjustment
During the first few days of the cleanse, you may feel hungry, irritable, foggy, or tired. You may also experience withdrawal symptoms from not consuming caffeine or sugar. That usually means a headache and/or cravings for sweets. Right now, your body will be burning through its stored reserves of carbohydrates, known as glycogen. When glycogen drops you also lose water. That means you’re likely to pee more. You’ll probably drop a few pounds of “water weight.”
Day 3-4: The Transition
By now your body will start burning fat. Surprisingly, your hunger may actually decrease as your liver works to metabolize fat-soluble toxins. Your energy should begin to stabilize as your blood sugar levels stabilize. This is the part of the fast when many people often say they start feeling “clear,” “light,” or “clean.”
Day 5-7: The Glow Zone
If you’ve made it this far the next few days should be more pleasant. Cravings fade, you’re less bloated, and your stomach flattens a bit. Many people report experiencing mental clarity, a great mood and more energy during this phase of the cleanse. You may be feeling terrific, but it’s important to keep in mind that your body is running very low on calories and protein. You’re taking in less than half the usual number of calories. That’s why a juice cleanse is not sustainable over a longer period of time.
Are the detox claims true? More study is needed.
As popular as they’ve become with celebrities and proponents of alternative healing, juice cleanses have not been very well studied in the traditional medical world. The small number of studies that have been done are of questionable quality–poorly designed, with too few participants and a lack of review by other experts. To date there have been no large-scale clinical trials proving that juice cleanses eliminate specific toxins and improve metabolic health over time.
What about the risks?
The first thing to remember is that a juice fast is not a way to lose weight for the long term. In most cases you will return to the weight you started at before the cleanse. That’s because a lot of the weight you lost was water weight which is quickly gained back. Plus, you’re unlikely to maintain eating half the calories you usually do. Anecdotal reports indicate that juice cleanses are ineffective weight loss regimens; many people end up gaining more weight back than they lost during the cleanse.
Concerns about kidney health
While increasing the number of fluids you drink during a juice cleanse can be beneficial for your kidneys, many of the fruits and vegetables you’ll be consuming are high in a compound called oxalates which can cause kidney problems when eaten in high quantities. People with chronic kidney disease, in fact, could be at risk for something called “oxalate nephropathy” which could sometimes lead to kidney failure–another good reason to speak with your healthcare provider before starting any sort of juice cleanse.
Harm to your gut and mouth biome?
Recent studies point to the possibility that consuming large amounts of juice with little fiber can increase inflammation-linked bacteria in the gut and mouth. Juicing strips away most of the fiber in fruits and vegetables that feed helpful bacteria in your mouth and gut. Without the fiber harmful sugar-loving bacteria multiply which could lead to inflammation and reduced gut health.
So, should you turn up the juice?
Once again, there is no medical evidence that juice cleanses can help “detoxify” you. Your body has its own detox mechanisms, notably in the liver, kidney, lungs, and skin, that regularly help eliminate harmful substances. But people still swear by it, reporting increased energy, mental clarity, quick weight and other juicing benefits. More study is needed before anyone can say for sure that juicing is good for you.
