There's a new show out called The Truth About Food. I just watched the Younger and Prettier (or something like that) episode. One of the experiments was the Detox. I have a friend who does that, she detoxes a lot. Juices, Waters, Fasting.
So for a week, they had the control group who ate chocolate, pasta, tea, etc. And then there was the Detox group who had blender juices (mmm, garlic and onion with other stuff for breakfast, delish) for a week, though they graduated into salads and white fish after a bit. Once the week was over, they compared urine and saliva samples from the start with urine and saliva samples at the end and the result?
NO. FREAKING. DIFFERENCE. None. The reason? The liver and kidney usually process most stuff within 24-48 hours. A day long fast may make a difference but the body is terribly efficient when it comes to toxins (unless your organs don't work, of course) and detoxing does nothing.
Another surprising experiment was the Water Is Good For Skin one. They took a set of twins and had one drink up to 2 liters a day and the other drink no straight water, just juices, coffee, and tea. They started off at a skin specialist and ended with one. Their skins were analyzed for moisture content, clarity, etc. And the result?
NO. FREAKING. DIFFERENCE. None. The reason was that up to a third of the water you get comes from your food. However, water IS a good appetite suppressant and many times, your body will ask for food when you are thirsty because you get so much moisture from what you eat. So my personal opinion? Drink your water anyways. It won't give you Photoshop perfect skin but it will help your body function better. After all, I drink 2 liters and 2 cups daily and it does a wonder for my kidney.
I love this show, I'm going to keep watching it. :D