fatbird said:
................ raw brain, raw liver (a significant source of vitamin C and others), and other varieties of offal..............
Seriously. that's what you believe we all should eat?
Bl**dy ' ell.
Not only those things. You should also eat seal blubber which is very high in vitamins E, A and D.
Unfortunately it's not the whole story and Inuit are definitely not amongst the most healthy people in the world and they don't have as long a life expectancy as most other north american groups. Most of these things are due to genetic variation and those humans who are predisposed to thrive on certain types of diet will do better than those who aren't. Whilst it is observed that diets rich in fish oils reduce instances of thrombotic conditions and improve cardio vascular health, too much raises the liklihood of hemorragic stroke. This may be tempered by some genetic mechanism in Inuit but isn't in europeans, except for eastern Finns.
A typical european genetic mutation is Factor V Leiden. It's a blood clotting disorder and potentially fatal. You need two copies of the gene for the trait to be expressed but in parts of europe at least 20% of the population carry one copy of this potentially fatal disease. The original mutation occured in one person at some time back in history so how can it be that something deadly can grow to such levels within a population? The answer is that it also has some benefits. Blood which clots more easily is helpful for women during childbirth and also for healing wounds. Another condition which is seen as somewhat debilitating with potentially fatal results due to complications is sickle cell anemia. However, it is widespread in subsaharan africa and it turns out to offer some degree of protection against malaria. Life expectancy for sufferers used to be about 42 for women and 48 for men but evolution is only really concerned with having people live long enough to reproduce and raise their children to an age where they can then propagate the species. So, that's long enough and more longevity is a bonus, except for the Chancellor of the Exchequor who has pensions to worry about.
It is hard to quantify the life expectancy of north american Inuit populations accurately because they do things like smoke and drink alcohol. Siberian Inuit however have been studied and life expectancy of some groups was only 44 with only 25% living past 60. Now I like my roasted reindeer leg bone marrow as much as the next man but, as a northern european, I am genetically adapted to things like dairy, something which the Saami are not.