Fasting was extensively researched in Soviet Russia as a potential cure for many ailments, from auto-immune diseases to mental illness. Tens of thousands of people were treated with 14-40 day water fasts (under constant supervision and testing), roughly 2/3rds reported various levels of success. I don't think much of the studies have ever been translated into English.
Watched 25 minutes of it so far and it's absolutely fascinating, thanks so much for sharing.
One key point so far for anyone who hasn't watched yet: the fasts involved here are long (multiple weeks) and treatment that you do under medical supervision, and it needs to happen properly, meaning along with it you need proper exercise, getting your blood tested, and various other things, in some cases even including classical medication (possibly even larger doses)... so in general it's not merely "just don't eat for N days and you'll get cured".
It is fascinating, but around 18 mins 45 seconds "cancer" is noted as a contraindication for fasting! Unfortunately there was no mention of what the cancer type, metastatic status, etc..