Cola, not coffee, was tied to high blood pressure in one large study
In one 12-year study of 155,594 US women, drinkers of cola, sugared or diet, were more likely to develop high blood pressure. Coffee drinkers were not.
What the study found
In 155,594 women, cola tracked with high blood pressure; coffee didn't
Over 12 years, 155,594 US nurses' total caffeine intake showed no steady link to high blood pressure, and coffee showed none. Cola did, sugared or diet, with risk rising as intake rose. It was the drink, not the caffeine total, that tracked with risk.
The caveat · Could be cola drinkers, not cola
Something else in cola, or about the people who drink it, may carry the risk, and the authors could not say what. Caffeine intake was not flat either: women in the middle fifth had 12 to 13% higher risk than the lowest. Both intake and diagnosis were reported by the women themselves.