Experiments with cats have shown that a diet of irradiated food causes destruction of the nerve insulator myelin and subsequent neurological diseases. The good news is that, removed the radiactive diet, cats recover slowly but satisfactorily.
While the authors argue that they think that the cause of the myeline destruction is "species specific" they provide no evidence for this claim, which sounds in fact mere wishful thinking. Food irradiation is somewhat common in industrial countries, especially the ultra-modernist (for some things) USA, being a rather controversial method of food preservation.
Significatively multiple sclerosis (one of the major diseases caused by myelin deterioration) is much more common in North America and some parts of Europe (areas where food irradiation is relatively common) than anywhere else in the world, though genetic factors may also be at play.
Other illnesses associated with faulty myelin are autism and alzheimer, while the latter is clearly an age-related problem, autism appears to have increased a lot in the last decades, precisely since food irradiation became common.