Hi Nelie
You said yourself that antioxidants protect NORMAL tissue against radiation.
So why wouldn't people take antioxidants if it helps protect the normal tissue?
Antioxidants don't promote cancer cells to grow.

Partner diagnosed with low grade mucoepidermoid carcinoma of sublingual gland, 2nd opinion graded intermediate grade, surgery to remove,lymph nodes removed one side, nodes all clear. Treatment - radiation.