1. Humans have not been eating cows produced by modern methods for millions of years. Cow diet, genetics, and lifecycle is quite unnatural at this point. (This is the overwhelming bulk of cow consumption, of course your local micro farm produces cows more similar to ancient cows)

2. Humans haven’t been eating cow (or meat generally) on this scale ever before in history.

3. Even despite the above, we genuinely don’t know to what extent baseline human health is dependent on traditional diet. It’s not impossible that there exists a modern radical diet that greatly improves health and longevity without including any “natural” foods.