Apparently so, according to this new study:
http://www.ivanhoe.com/channels/p_channelstory.cfm?storyid=17125

“While it is believed the development of type-1 diabetes has some hereditary influences, research also suggests environmental factors—including diet—play a role. Researchers from The Barbara Davis Center for Childhood Diabetes in Aurora, Colo. report a diet high in omega-3 fatty acids may be associated with a decreased risk of pancreatic islet autoimmunity, a condition associated with the development of type-1 diabetes.”