I'll confess that I haven't researched this and am only speaking from short-term experience. However: I have always been very paranoid about handling raw meat. Always very careful to keep it separated from everything else in the shopping cart and grocery bags. Kept it in a different area of my fridge so it couldn't 'contaminate' anything else. Regularly bleached out the meat drawer before adding new raw meat. Don't get me wrong; I have always loved to eat cooked meat. I wasn't against meat. I had just heard too many wives' tales at home about the DANGERS of raw meat. Last May I began feeding my dogs a raw food diet. Gradually I stopped bleaching and scrubbing everything in my house that might have been touched by a bit of raw meat. Now when I feed my buddies I use soap and water to clean up the mess and then get on with life. Here's how it affects me. I have been sickly my whole life; always the first to catch a cold or flu. It's just something I accepted about myself. But since I began handling raw meat on a daily basis [and (horrors) even trying a bite or two of it on occasion] I find that I am no longer using up my sick days at work. I didn't catch the stomach virus that went around at work last week. I don't feel bad all the time. I'd like to say it is related to eating Paleo, but I can't. I'm still struggling with cutting sugar and starch out of my diet. So I'm not eating right yet. But I believe that being exposed to the 'extras' in the meat may be building up my immune system. As I said earlier, no research or science to back myself up. Just personal opinion.