Nutritional studies have shown that low-dose food irradiation does not cause significant changes in nutritional value.
Even at the higher doses of irradiation used to extend shelf-life or control harmful bacteria, nutritional losses are less than, or about the same as cooking and freezing. At lower doses, nutrient losses are either not measurable or insignificant. Any change in nutritional value caused by irradiation depends on a number of factors, including the radiation dose, the type of food, packaging and processing conditions, such as temperature during irradiation and storage time. All forms of food processing--cooking, freezing, canning and even storing foods--lower the amounts of some nutrients.
Persons opposed to irradiation may claim high nutrient losses; however they incorrectly refer to studies that expose food to high doses not permitted in the United States or they refer to older studies that failed to accurately measure nutritional value (Diehl, 1990; Thorne, 1991).