Well, short length of living was mostly connected with risky hunting, a lot of parazites in the nature, no medical aid etc.
During "times of damned tsarizm" there were some movements to improve, but crossed by bringing vodka to them. The issue is that these nations have lack of alcoholdehydrogenase (there was no natural selection by this because of no fermentation is available at low environmental temperatures) and they can't regulate consumation of alcohol, becoming alcoholics very quickly).
During Soviet power there were sufficient improvements with medical aid, education, settlement etc., but vodka was not removed. After catastroika nobody needed them, and I'm afraid they will die out, because all positive things deteriorate, but vodka is continuing.
