The other day I was reheating some food in the microwave for dinner, and I noticed (yet again) that my beans were still not very warm. I started thinking about how they don't absorb the heat energy from the microwaves as much as other food does, and they have a lot of starch, and then I wondered: Could starch be a good material for radiation shielding? Today I googled it, and the second result was from NASA! Here it is:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20120006695.pdf
So a starch-based material would be a very potent radiation shield, and it could be grown in space! I thought it was pretty interesting. What else do you know on the topic?