Regarding 1, it is also worth noting that we may not ever achieve truth here, at least not in our lifetimes. "What should I eat so I have less risk of vascular

Regarding 1, it is also worth noting that we may not ever achieve truth here, at least not in our lifetimes. "What should I eat so I have less risk of vascular disease and cancer, delay decrepitude as long as possible, and have good to excellent ongoing physical and mental function?" This question is almost impossible to answer. The basic problem is to experiment on oneself, you need to use surrogate markers of ill health, and you never know if you are on the right track for what matters. A recent example are drugs which improve the measured HDL value (good cholesterol), but fail to reduce cardiovascular events. Randomised trials on the other hand give us average effects in certain populations, but how this relates to the individual is always unclear. This is why people are still arguing what some randomised trials mean 20 years later (like the Lyon diet study, which is uninterpretable anyway due to woeful dropout). RCTs with diet are terribly difficult, prolonged and expensive to conduct. Considering all this, my approach is to just try and eat less, hence mitigating the downside of dietary induced problems. A good way to eat less is to eat more non-starchy vegetables, which are mostly micronutrients embedded in paper. There are also a few surrogate markers with strong evidence it is worth measuring in a serial fashion and trying to improve eg LDL, glucose tolerance, CRP. Coronary calcium scoring with CT is also worth doing if you are 40+ and have been eating like shit most of your life or have bad genetics for heart disease.