How Safe is Food Irradiation?

Food irradiation is the process of exposing food to ionizing radiation in order to kill bacteria and other organisms.  A product of the 1950s, when atomic energy was the silver bullet for everything, food irradiation is commonplace in the world's food supply chain.  Something that has always nagged at me - we know that ionizing radiation such as gamma rays or x-rays damage DNA.  So why is not ingesting food with damaged DNA harmful?  I have no data to support this unease, but it still bugs me.

Irradiation of Food and Food Packaging on the U.S. FDA website has several pamphlets regarding irradiation. In 1963, the Food and Drug Administration (FDA) found the irradiation of food to be safe. It also declares that irradiation makes meat and poultry safer by reducing the numbers of harmful bacteria and parasites. The conclusion is that irradiation is an important food safety tool in fighting foodborne illness.  Eating like an astronaut: our six-course space food taste explains that NASA prepared irradiated meats for the astronauts.  (In case you are interested, the authors considered the lunch enjoyable.)

Cat-food irradiation banned as pet theory proved tells that Australia has just ceased a mandated policy of irradiating pet food.  Over 90 cats last year were determined to have developed neurological damage after eating irradiated pet food.  Curiously dogs have not exhibited similar symptoms.  Mmm.  Why all of a sudden after irradiation has been used for decades?  There is a lot of noise out there - it is hard to determine what is truth.