As a registered dietitian a juice cleanse is the last thing I would recommend to my clients, family and friends. First of all there is no such thing as “cleansing” or “detoxing” your body through diet or beverages. There is absolutely no scientific proof that the ingredients in these drinks such as cayenne and lemon juice or apple cider vinegar do anything to decrease free radical production, and cleanse the body. Your body is a finely tuned machine. Your liver, kidneys, and intestines naturally cleanse your body. The cells of your body are constantly dying off and being reproduced. There is nothing you can do to through diet to assist with this process.
There are many drawbacks to these juice cleanses. First of all, the juices are typically cold pressed, leaving the dietary fiber behind. Dietary fiber is something your body needs to function properly. They also lack in protein. Without protein in the diet your body must pull it from the muscles. This in turn will result in weight loss from lean muscle mass and water weight. Since muscle fuels the metabolism, loss of muscle mass will slow the metabolic rate making it easier to regain weight when you go back to your usual eating habits.
Juicing companies claim that nutrients are easier to absorb as a juice rather than as a whole food. There is no science to support this. They also claim that it gives the body a rest from digesting roughage. There is no benefit to this. Actually the opposite is true. If you give your body too long of a “rest” it could result in intestinal dysfunction.
Now, for the everyday person who doesn’t get in all for their veggie requirements, having a juice that’s mostly vegetable based (low in sugar) may be a good idea. Keep it in moderation. One veggie juice a day can give you a plethora of nutrients. Just make sure the rest of your diet has adequate protein and fiber! And remember it’s always a better idea to eat you calories rather than drink them, especially when the goal is weight management!