I get protein from egg (mostly) whites (the expensive "free roaming chickens" type), low-fat turkey slices and hot dogs, chicken, fresh veggie juice, small amounts in veggies, etc.

Lentils are another thing I avoid - too rough.

Cow's milk is something that I will never have again, including any product that contains casein. I use a product called DariFree, which is powdered potato with other ingredients, instead of milk. The casein in goat's milk is much healthier than the cow's milk type, but goat's milk is still high in cholesterol. It's very tasty and I drank it for a while, but ultimately gave that up as well. Milk actually can cause osteoporosis, but that's better explained by a professional. There are also different types of cows and different milk from them, some not as bad. We probably get the worst kinds. I get very zoned out from casein, even from small amounts consumed by accident.

My wife is currently experiencing menopausal "hot flashes" that could be alleviated by soy supplements, but soy wreaks havoc on the immune and hormonal systems so she's not using it. We used to be avid soy consumers.

The website of Dr. J, below, a vet, has most of the information that convinced me to avoid cow dairy, corn, soy, lentils and other foods in addition to gluten grains. He also has celiac disease, as I do, and is adamantly anti-gluten for everyone. He's finished a book, about food-related disorders, that is coming out soon.

The Answer

We are certainly the only species to drink the milk of another animal. To compound matters, look at the animal we chose to nurse: a huge beast that never moves. He is one of the most lethargic of earths mammals. The fact is that the composition of their milk fits their nursing period and their weight at adulthood. The universal truth is that all mammals nurse their young until they triple their birth weight. This ranges from three weeks in the guinea pig to three years in the elephant. Every other mammal is pretty much somewhere in between.
The Answer