When I was in college I took a class called "Vertebrate Form and Function". We studied EVERYTHING like we were in veterinary school. We were told that the ONLY mammal that didn't eventually decrease production of or lose the lactase enzyme altogether (needed for milk digestion) was the CAT. As humans age, we lose the ability to produce that enzyme. Although, I've heard of some pretty old folks that could still drink milk. Sometimes I can eat dairy and not have it bother me. MOST of the time I get really sick with horrible intestinal cramping. I also have my gallbladder out. It seems I needed that little bugger more than I thought. I've pretty much been sick with my gut ever since... and it's been YEARS ago. I think there are other components of milk that make me sick. I still eat ice cream (and get sick). I just can't seem to give the stuff up. Lactaid doesn't always stop the cramping.
We don't know what tomorrow brings,
but we are alive today!