fasting and hypothyroidism

Hi, has anyone tried fasting, drinking water only for 3-7 days to cure hypothyroidism ? My father fasted 1 week and his eye sight improved dramatically. My mother fasted 42 days on water only during cancer. Although it did not cure her in the end I believed it prolonged her life. I have been told that fasting as detox method can kick start your metabolism and cure all kinds of diseases. I dont fancy the idea of taking hormones all my life and look for alternative treatments. Thanks Klara