Life expectancy being 25 doesn't mean nobody lives past 25. Estimates that low for early humans is skewed by huge infant mortality rates. IIRC living into the 40s or 50s was typical for an early human that survived to adulthood. 60s or 70s not uncommon.
We can't actually tell the age of death of human fossils past the time that wisdom teeth grow in. There's no way of telling whether a fossilized skeleton was 30 at death or 50 at death. Even then, we don't necessarily have a representative sample.
The Sami, as I mentioned, have been studied. They are a tribe of reindeer herders in northern Scandinavia. They eat a diet consisting of almost exclusively reindeer meat. They have lower cancer incidence than Finns (https://onlinelibrary.wiley.com/doi/full/10.1002/ijc.10486).
> They eat a diet consisting of almost exclusively reindeer meat.
Very far from a typical meat diet (quoting from your link):
"The dietary habits of the Sami differ from those of the other Finns. Reindeer meat (low in fat) and fish have been important foodstuffs in the diet of Sami people. Intake of vegetables and fresh fruits has been low, but berries were eaten, especially by the North Sami. Although nowadays dietary habits have become more similar to that of the rest of the population, still more than 90% of male Sami reindeer herders eat reindeer meat at least 3 times a week and almost 50% eat fish at least twice a week. Reindeer meat and fish contain high concentrations of healthy lipids, trace elements (e.g., selenium), minerals and vitamins. Arctic people usually rely on blood, liver or kidneys from animals to obtain adequate nutrition."
