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brazil84 comments on Lifestyle interventions to increase longevity - Less Wrong

120 Post author: RomeoStevens 28 February 2014 06:28AM

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Comment author: brazil84 27 February 2014 11:53:03PM 4 points [-]

I was pretty surprised about blood donation. My intuition is screaming that it must be one of those correlation/causation things where unhealthy people are discouraged from donating blood, but on the other hand, the researchers are all surely very well aware of this issue and must have taken steps to correct for it.

Anyway, have you thought about typically sub-clinical viruses like cytomegalovirus? I recall reading that a CMV infection cuts a few years from your life expectancy. I don't have research to back it up, but I think it's a good idea to avoid having intimate contact (e.g. casual sex) with lots of people.

Comment author: Lumifer 28 February 2014 01:19:33AM 9 points [-]

I was pretty surprised about blood donation.

Males tend to have iron overload which is bad for you. The easiest way to fix it is to bleed on a regular basis.

Women don't have that problem.

Comment author: khafra 28 February 2014 06:22:08PM *  12 points [-]

Those of us disqualified from donating blood should probably try to get into some form of exercise that involves a lot of blood loss; like skateboarding over sharp rocks, fencing with un-foiled blades, or taunting apex predators in their natural habitat. A new Ev-psych explanation for why men engage in this sort of activity more than women!

Comment author: Nornagest 28 February 2014 06:58:07PM 3 points [-]

Huh, a plausible longevity argument for Mensur fencing. Never thought I'd see that in the wild.

(Snark aside, I imagine it'd be rather difficult to find a hobby that reliably takes a pint of blood a year and doesn't kill or seriously injure you.)

Comment author: Lumifer 28 February 2014 08:40:16PM 11 points [-]

I imagine it'd be rather difficult to find a hobby that reliably takes a pint of blood a year and doesn't kill or seriously injure you.

Pet leeches :-P

Comment author: CellBioGuy 28 February 2014 04:58:37AM 2 points [-]

Wouldn't necessarily call it iron overload, but definitely higher levels.

Hmmm... as someone who is a carrier for hemochromatosis (thanks 23andme!) perhaps I should consider this more than the average person...

Comment author: Lumifer 28 February 2014 05:52:58AM 1 point [-]

Wouldn't necessarily call it iron overload

I thought it was a pretty standard term.

Comment author: CellBioGuy 28 February 2014 07:26:14AM *  3 points [-]

Yes it is, but generally for rather more clinically significant levels. The difference between men and women exists but is much much smaller than the difference you get from, say, hereditary hemochromatosis. Ordinarily I hate nomenclature quibbles but labelling the normal state of half the population as a pathology seems out of place.

Comment author: Lumifer 28 February 2014 06:21:27PM 1 point [-]

Well, nobody claims all males suffer from iron overload.

On the other hand, the correlation between blood donation and mortality seems to suggest that there is a nontrivial amount of people (very likely males) with "clinically significant levels" who are probably not aware of that fact.

Comment author: maia 28 February 2014 04:42:39AM *  1 point [-]

Hmm. Do the studies account for this?

Also, that would mean women on medication that stops their period also might have this problem.

Comment author: Vaniver 28 February 2014 05:07:12AM 3 points [-]

Also, that would mean women on medication that stops their period also might have this problem.

Indeed; also post-menopausal women.

Comment author: G0W51 25 October 2014 01:46:52AM 0 points [-]

I suggest you read this article, which suggests that blood donation doesn't decrease mortality.

What do you (or anyone else) think of it?

Comment author: RomeoStevens 03 February 2015 03:56:15AM 1 point [-]

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.

Comment author: G0W51 05 February 2015 12:49:42AM 0 points [-]

I tried to find it but failed. Do you recall it's title or authors?

Comment author: RomeoStevens 05 February 2015 06:11:49AM 0 points [-]

Sorry I don't. Don't see it with a cursory search in google scholar either.

Comment author: G0W51 07 February 2015 09:43:08PM 0 points [-]

Oh well. I'll still mention this in Immortality: A Practical Guide if that's okay with you.

Comment author: RomeoStevens 07 February 2015 11:48:47PM *  1 point [-]

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.

Comment author: G0W51 08 February 2015 02:03:18PM 0 points [-]

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.

Comment author: Lumifer 25 October 2014 04:04:04AM 0 points [-]

My post mentions a specific reason -- iron overload -- which is bad for you. Blood donation fixes that problem if it exists.

That particular argument does not rely on correlations at all.

Comment author: G0W51 26 October 2014 03:35:38PM 0 points [-]

Your post also mentioned that males tend to have iron overload. I find this to be suspect, as if males tended to have iron overload, the study would have probably found that blood donation decreases mortality.

That said, for those who do have iron overload, blood donation likely does fix that.

Comment author: Lumifer 27 October 2014 01:16:18AM 0 points [-]

I don't know how prevalent iron overload is. It might well be rare enough so that its effects are lost in the noise. I wasn't claiming that donating blood is necessarily healthy, my point was rather that mechanisms (not correlations) by which blood donation could be useful for health exist.

Comment author: G0W51 04 November 2014 03:42:21PM 0 points [-]

If you don't know how prevalent iron overload is, then you can't know that men tend to have it, so I suggest editing you comment to say "some men have iron overload" instead of "men tend to have iron overload."

Comment author: ChrisT 10 December 2014 03:54:16PM 1 point [-]

Iron overload / haemochromatosis occurs in approx 0.5% of the population of Northern European origin (and less in other ethnicities). Undiagnosed and untreated the iron will build up in the liver and other organs and cause a variety of unpleasant side effects. Venesection is the standard treatment, though I suggest that less than 0.5% of the population is not significant enough to explain the other studies.

Source: http://www.haemochromatosis.org.uk/index.html