I just read a mention in one story that the fear and uncertainty over the nuclear situation could be hampering relief efforts because people in Japan away from the disaster zones are starting to stock up on food just as supplies need to be diverted to the disaster areas. Another knock on effect of this trifecta of disasters in Japan.

I have read reports that many store shelves in Tokyo are apparently bare, although that could be more because normal food deliveries were disrupted by the earthquake rather than panic buying. In any just-in-time supply chain, any disruption can lead to bare shelves quickly. My friend in Tokyo mentioned bare shelves in a convenience store, but the larger supermarket near her seemed OK, so it's hard to say how accurate the reporting is about this. She didn't notice any signs of panic buying at the supermarket.