I think that these hard to prove health factors vary a lot depending on a persons genetics, diet, and lifestyle. Big studies with small statistical results usin

I think that these hard to prove health factors vary a lot depending on a persons genetics, diet, and lifestyle. Big studies with small statistical results using an average of outcomes is not going to be very useful for you, a single individual. 100% of people who don't eat Vitamin C get scurvy. This is useful information for an individual person. A study of 20,000 people over 20 years that finds that people with a vitamin D level below a certain number died on average 100 day earlier than the ones with vitamin D above that level is useless to an individual. Maybe with individual genetic testing some more useful things can be learned about health for individual people, but for now the low hanging fruit of health studies has been picked. Instead more focus on how individual people can figure out what works for them should be done.