It is eating too much protein, specifically animal protein, that is the main cause of sickness, and shorter lifespan. There was a documentary on the bbc about this, I can't find it because youtube took it down, but if I find another video, I will post it.
As for Herschel Walker, his diet is not good, especially for mental health, when you are doing a lot of thinking, and physical activity. It may be the cause of his mental illness.
animal protein is the reason we have bigger brains than other primates :cheff:
your brain alone consumes upwards 40-60% of the protein AND fat that you consume
there are nicarauguans who live til 90+ and eat nothing but goat and fermented corn.(they use their own saliva and chew it up and spit out and save it :wot: )