Good for prevention but it's actually not a cure to anything. And also, you need to be mindful and critical coz some of them are infused with steroids and other adrenaline boosting compounds and even anesthesia so you feel better when you drink them. Besides, if you want to eat healthy then fresh produce should be the way and not some processed food supplement that has preservatives, it has preservatives of course because how else will it last in the shelves if it does not have any... ^_^