Eggs are bad for you! Eggs are good for you! Meat is bad for you! Meat is good for you! Alcohol is good for you! Alcohol isn't good for you!
I swear, if you listen to and heed all this advice you will go crazy. I think the best thing to do is ignore all this crap, eat *reasonably* (not too much of any one thing, have a balanced diet) and just ENJOY the things you like, regardless of people saying they're good or bad for you, because life is short anyway and we might as well enjoy it while we have it.
I see so many eating bland vegan diets, thinking it's so good for them; I doubt any of them will live longer than typical omnivores.
While this is true, the only reason we know what a 'balanced' diet looks like, or what it's *near* atleast, is the years of study. There's nothing to say what a balanced diet is without some understanding of the component parts and their effect on your body.
Unfortunately it looks like with our current research methodology we are at the limits of what can be said about food... we're now wobbling around saying things are good, and then bad, and then maybe neutral. You're right about not listening too much to each individual study's result.
So rejoice, you can relax and not worry because at the coarse level we understand roughly what balanced is.