Fiber has been shown to prevent some forms of cancer. Fiber promotes healthy regular bowel movements and moves food quickly through the digestive tract to minimize the time that potential carcinogens are in the intestines.
The easiest way to get fiber in your daily diet is to eat fruit and vegetables (not juicing-it eliminates the fiber), eat beans and whole grains (i.e. brown rice, barley, oatmeal (but not instant oatmeal), popcorn (but not movie theatre popcorn!) The rule of thumb concerning whole grains: the longer the cooking time the more fiber they contain.
If you love your fresh juices but want to hold onto the fiber, all you need to do is make them in a regular blender. Cut up greens, fruit and veggies into small chunks and put them in blender with some water and ice cubes. Certain fruits like bananas or avocados will make your juice drink thicker. Here’s a quick demo of how to make a kale and fruit smoothie.