High blood pressure is a major risk factor for heart disease, and recent evidence suggests that it is increasing across the globe, with more than 1.5 billion people expected to have high blood pressure by 2025, or around one in three adults over the age 20.
Diet plays a major role in blood pressure and food makers are looking for ways to bring levels down through new formulations. Potassium is among the nutrients with the strongest evidence of its benefit in this area, but most of the evidence has used the chloride salt form.
The mineral is however also found naturally in fruits and vegetables, consumption of which has been associated with lower blood pressure levels.
Researchers in the UK tested the effects of potassium citrate on blood pressure to find out if people would get the same benefits from potassium-rich foods as they do from potassium chloride supplements.
The findings could influence formulation decisions. Potassium is important for regulating pH levels in body fluids, blood pressure, muscle and nerve cells, osmotic pressure and water balance. The mineral is commonly used in diet products and meal replacement bars because it is particularly critical for individuals who are dieting or taking diuretics.
The randomized, crossover trial compared the effects of a daily dose of 96 mmol of potassium chloride taken for one week, with the same daily dose of potassium citrate taken for another week in 14 hypertensive individuals.
Both forms of potassium significantly lowered blood pressure to similar levels.
"Our results, in conjunction with the evidence from many previous trials that potassium chloride has a significant blood pressure-lowering effect, suggest that potassium citrate has a similar effect on blood pressure as potassium chloride," write the researchers in this month's issue of Hypertension (vol 45, issue 4, pp571-4).
"These results support other evidence for an increase in potassium intake and indicate that potassium does not need to be given in the form of chloride to lower blood pressure."