Todd > ...we can point to populations with very low rates of heart disease
whose intake of foreign proteins is nevertheless high (e.g., Masai).

I don't think the Masai are a good example.  The Masai traditional diet
contains only one non-paleo component: milk.   And I suspect that the milk
from natural, free range, grass eating (rather than the milk from modern
grain fed, hormone injected) cattle, while not paleo, might be a lesser
offending non-paleo food.  I'd put grains as the biggest sources of foreign
proteins, with natural cow's milk somewhere down the list.   Do you have a
population where the ingestion of grains is high yet the rates of heart
disease is low?

And perhaps I'm missing something, but I don't find your conclusion that
foreign proteins don't influence heart disease rates the least bit obvious.

Thanks.

Jim