Blood donors (41 observational studies and 3 experimental studies).
Systematic review to summarize and evaluate existing observational and experimental studies on effects of blood donation on cardiovascular risk and disease in donor and general populations.
From the 44 included studies, 14 had a quality assessment score of 7 or higher. Of those, a majority of 9 studies reported a protective effect of blood donation, while 5 studies found no effects on cardiovascular risk factors. Results on other outcomes were inconsistent and study quality was generally poor. It was unclear whether blood donation protected against cardiovascular disease. High quality studies were lacking.