When my doctor’s advice was “You have terminal melanoma, go home and get your affairs in order”, and I watched him write “palliative care only” on my file, then I was forced to do my own research and experimentation.
That was over 8 years ago.
I am strict vegan.
I have a heaped teaspoon of vitamin C dissolved in a glass of luke warm water twice a day (every day – no misses).
I have removed all added sugar and alcohol from my diet.
I get reasonable exercise.
Like many others advice, avoid stress, anger, resentment. Cultivate acceptance and appreciation to the greatest degree possible.
It’s all about removing impediments to immune system function.
Stress (fight or flight response) shuts down immune response.
Many things can be the rate limiting step to immune function, in most people it is vitamin C most of the time; and it can be many other things also.
I haven’t had a cold or flu since starting this regime.
And there are lots of things one needs to be conscious of, for vegans B12 and omega 3/6 ratio are the two main ones; but lots of other deficiencies in diet can be important to different people.
So there is a lot of “suck it and see”, as we are each different in many subtle yet important biochemical ways. See what works for you. Become as conscious as possible (a never ending journey) of how your body reacts to food and environments. Select those that work for you.