I agree I should have mentioned that diet is just one important parameter of the whole picture. A person's genetic makeup and their microbiome (which depends on genetic factors as well), predicts how everything would interact. How the diet will actually affect you, also depends on the epigenetics, which is affected by things like stressors in your childhood. There is so much happening in there, some of factors however that are to an extent in control for us are a dietary modification, stress reduction and proper sleep if you think you need it. In a nutshell like you said, we should focus on staying health - both physical and mental.