There is a review floating around where some researchers investigated exactly this claim and concluded that the reverse causation effect only accounted for about 30% of the effect. This is one of those situations where the costs and benefits are a massive enough ratio to make it worth the risk that it isn’t doing anything IMO.
They discuss why they think positive results happened in previous studies. I’m updating away from the hypothesis as a result of finding this. Blood donation still has enough other studies showing various benefits and essentially no studies showing harm (except for excessive donation, more than twice a year IIRC) that I think it is worth it, but the mortality effects might not be very high.
Keep in that one of blood donation’s supposed mechanisms is to prevent iron overload, but only ~0.5% of the population has iron overload to begin with. See ChrisT’s comment.
There is a review floating around where some researchers investigated exactly this claim and concluded that the reverse causation effect only accounted for about 30% of the effect. This is one of those situations where the costs and benefits are a massive enough ratio to make it worth the risk that it isn’t doing anything IMO.
I tried to find it but failed. Do you recall it’s title or authors?
Sorry I don’t. Don’t see it with a cursory search in google scholar either.
Oh well. I’ll still mention this in Immortality: A Practical Guide if that’s okay with you.
Oh if you want to cite it I’ll look a little harder.
This review actually seems pretty thorough and reports a negative result (though still positive for people who have already experienced a CHD event): http://circ.ahajournals.org/content/103/1/52.full
They discuss why they think positive results happened in previous studies. I’m updating away from the hypothesis as a result of finding this. Blood donation still has enough other studies showing various benefits and essentially no studies showing harm (except for excessive donation, more than twice a year IIRC) that I think it is worth it, but the mortality effects might not be very high.
Keep in that one of blood donation’s supposed mechanisms is to prevent iron overload, but only ~0.5% of the population has iron overload to begin with. See ChrisT’s comment.