Blood pressure and Coffee

Caffeine has previously been implicated in increasing the risk of high blood pressure; however, recent studies have not confirmed any association. In a 12-year study of 155,000 female nurses, large amounts of coffee did not induce a "risky rise in blood pressure".Previous studies had already shown statistically insignificant associations between coffee drinking and clinical hypertension. Effect of coffee on morbidity and mortality due to its effect on blood pressure is too weak, and has not been studied. Other positive and negative effects of coffee on health would be difficult confounding factors.