The term is a valid one and well known, perhaps misplaced in terms of hot and cold temps, but I have heard it in this context too. Also it is more of a metaphoric term and I don’t think it has to do with blood thickness.
At best, the term “blood thinning” is very deceptive in a medical context. It can be used to describe reducing the amount of anti-coagulants in a person’s blood. In this sense, it has nothing to do with the viscosity or density of a person’s blood. There’s certainly no evidence that it has anything to do with the amount of resistant to frostbite. Incidentally, read that article that was linked to about risk factors for frostbite carefully. What it says is that there appear to be many risk factors for frostbite, both environmental and genetic. According to some studies, one of them is being African-American. Treating race as if it were the major factor in frostbite simply isn’t justified.
And ignoring race would be equally unjustified under the current evidence we have. Perhaps we currently should not treat it as a major factor, but then again we have seen nothing to rule it out as a major factor either.
O.K., but again all this really says is that we simply don’t know enough about what the relative influence of all the various factors in causing frostbite is. The answer to the OP is “Who knows? There hasn’t even been enough medical studies to find out.” In any case, that doesn’t affect the fact that the assumptions in the OP are wrong. Blood thinness, regardless of whether that means density or viscosity or proportion of anti-coagulants, apparently has nothing to do with protection against frostbite. American blacks are not taller or thinner than American whites. Eskimos can survive in hot weather, although they will apparently have more trouble standing it than other people.
Whee! I’m a lab tech, AND I live in the arctic! What a great thread!
Re: Aspirin. IIRC, it is an antiplatelet agent. It prevents clot formation by essentially sabotaging the action of one of the enzymes needed inside the platelet to begin the process.
Anecdotally, the Inuit do have more difficulty dealing with heat than non-inuit. I say this because I know white people born and raised here who can remain comfortable in a warm environment. Say, a busy bar. A lot of my inuit friends will be complaining that it’s too hot and will run outside for a minute or two with no jacket (in the dead of winter…like -60 degrees C) while most non-inuit feel fine.
I’m not sure about that. While the speculations that led the OP to pose his question are clearly ill-founded, that doesn’t have any bearing on an objective answer to the actual question.
While the original premises have been easily dismissed, research suggests that African-American men do face a significantly higher risk of frostbite, albeit for different reasons.
In answer to the OPs specific request for statistics, here is an abstract of a twenty-year study conducted by the U.S. Army on cold-weather injuries.