Saliva. Radiation therapy of the head and neck affects salivary flow and the saliva glands. It is this reduction and change in saliva that affects taste.
Affects taste. This is dependent on location of radiation and amount given. Radiation can definitely affect taste during and after treatment. Dry mouth resulting from the radiation can also contribute to this. Often, after treatment, your taste will return to normal. This can take weeks or months. Unfortunately, some patients seem to never fully get their taste completely back to normal.