I'm with Ya Beekissed. I do NOT disregard the possibility but, most often when canned the foods were not eaten for a period of time -- it was for "later", after all. In that time lids were always, always checked. Meats being the most concern, that was cooked longer, as pointed out. Raw milk?? Yep!! I drink it now & am careful with cleaning udders, containers, fast chill, etc.
IMO, the risk is in the chemicals and unsanitary issues from overcrowding in the commercial businesses. How many cases of autism, ADHD, diabetes, blood pressure, altzhimers, overweight issues, early puberty, and on and on -- were there years back?? I acknowledge science has come a long way to diagnose what may have existed then -- just not ever in these numbers. GMO plays a factor -- don't care what they say -- it is proven the food is NOT as nutritious as it once was in may of these items. We all have our own way of life -- all good.
This is where I deal with things and I have NO issues with those who work differently and do not "down" them for the extra effort. Hey, I don't smoke but, if you want to -- OK -- just not in my house, car or blow smoke at me, LOL, I don't like the smell. It's like "do you like vanilla or chocolate".......both are fine.