If you are trying to stay heart healthy by eating lots of fruits and vegetables, may we recommend the Sumo orange?  

It's a large, bumpy fruit with a knob on top. It's not the prettiest citrus on the block, but inside you'll find one of the sweetest oranges you've ever eaten. In recent months, you might have seen it at your local farmers market or at a high-end grocery store.

For more on the Sumo orange and its fascinating backstory, we're joined by David Karp. He writes a weekly farmers market column for the Los Angeles Times, and is a citrus researcher with the University of California at Riverside.