No doubt that healthy fat intake plays a role; however, one must also take into consideration the differences in poverty, sanitation (including potable water) and access to primary healthcare. On the other side of the coin, one of the very longest lived groups of people in the world are the Seventh Day Advenists in California who consume an almost entirely vegan diet.
It would appear that regardless of the meat or vegetable content, a diet that takes advantage of what nature has to offer that has not been too corrupted by man and avoidance of junk foods and processed, additive filled foods is the ticket to better health and longer life. As for myself, you can bet that meat will remain a part of my diet.