Robert Peel had unprocessed cornmeal distributed in Ireland during the Famine. It became known as Peel's Brimstone because it caused violent diarrhoea, which killed many people. (Cornmeal has to be processed with lye before becoming edible; nowadays this is part of the process before it is sold to the public.) I never heard of rice being distributed.

However, at one stage in the 1970s the EU did give away a large amount of surplus beef and butter; I was living in a poor area then and was pleased to get a parcel of both. I don't think it had a terrible effect on the economy - it was a once-off gift.