Meat has inherent risk when compared to plant derived foods, and this is about "persistent toxins" (PTs). These toxins "build up" in our tissues and thus may become a threat after consuming small bits of them over a long time span. Since these PTs build up in our tissues, they usually also build up in the tissues of animals. Thus eating animal tissue is exposing us to the buildup of PTs.

As an example: it is observed that then some PT got into the environment the small animals did not suffer from it, the slightly bigger animals that eat the small ones also did not, but the larger predators (owls and hawks, iirc) were dying because at their point in the food chain the build up of PTs reached lethal levels.

Like another comment said: dose matters. But I like to add that understanding persistence matters probably just as much.