There have been no VEGAN cultures we know of to date. This may be important - but the nutritional leaders of today (Fuhrman, McDougall, Campbell, Esselstyn, Novick, Ornish, Maksuta) do not believe so....;~)
Vitamin D and B12 are the only vitamins (that we know of) that can be derived from animal products.. fish are the only ones that contain them in significant quantities.
Those who have lived the longest - as cited in the Herbsman post above on the Fuhrman site did have the following similarities in their diets/lives however:
1. Plant strong
2. Low fat
3. Rich Mineral Content Soil
4. Fresh Air
5. Low Stress
6. Clean Water
7. Plenty of outdoor "exercise/work/play"
8. Life Purpose
9. Social praise of elderly
I agree that in hard times - we would eat anything to live. But "low fat plant strong" is where it's at - I really have to believe that.
A couple of great books to read by John Robbins are Healthy at 100 and A Diet for New America.... outstanding in my opinion.