Even though almost everyone is talking about juice cleanses, registered dietitians urged us to be wary: “There is no substantial scientific evidence to support the use of freshly squeezed juice for ‘cleansing’ purposes. Humans rely on the liver and the kidneys to separate out potentially toxic byproducts of metabolism.” The National Institutes of Health (NIH) point out that each of your kidneys “is made up of about a million filtering units” that remove about one to two quarts of waste and extra fluid a day via your urine. In other words, your body already has the whole detox thing covered.