While answering this question about the possible detrimental effects of iron deficiency caused by frequent blood donation, I was reminded of a theory I heard long ago about a possible benefit of mild iron deficiency for reducing cardiovascular disease. The theory goes that the lower incidence of cardiovascular disease in pre-menopausal women (vs men of a similar age) is due to mild, chronic iron deficiency induced by menstruation.
I found some old observational literature suggesting that there might be an association between blood donation and decreased incidence of cardiovascular disease. Somewhat more recently, a large retrospective study seemed to support this. However, neither is a controlled study, and I’ve not heard this possible benefit promulgated by the Red Cross or anyone else collecting blood.
Are there strong randomized data in support of the idea that regular blood donation reduces cardiovascular risk? Has the “optimal” hemoglobin concentration been determined?