Not sure who told you that but a ketogenic diet is a very low carb diet and under a certain carb thresold the body will start producing cortisol in order to counter hypoglycemia, cortisol is an immunosuppressant and I'm not sure your father needs that.
Also if he has a pancreatic cancer then a ketogenic diet could be dangerous and cause extreme hypoglycemia.
A ketogenic diet could work against cancer even though that's not entirely proven but it would take quite a long time because you need to tell your body to stop using carbs and start using fat as a fuel.
Using antioxidants and stopping inflammation first would be more effective against cancer : lots of omega 3 (always combine with vitamin E 400UI minimum), revesratrol, NAC, vitamin C could be of a help, there are many others out there
If you want to change his diet, I would suggest to stop eating any kind of processed food, stop eating refined sugar (use stevia NOT purevia NOT truvia which are bogus, sucralose or xylitol instead), stop using vegetable oils (olive oil is an exception) however ban colza, sunflower and other nasty oils, stop drinking coffee (because that puts a strain on adrenals and cause cortisol spikes), no alcohol, no smoking as well.
Boosting his immune system could be of a help : zinc is certainly beneficial, ashwagandha, vitamin D, vitamin E, Se methyl L selenocysteine (200mcg and never exceed that dose or take selenium supplements with it)
These can be combined together very easily without significant risks.
Edited by renfr, 01 September 2013 - 09:38 PM.