While the primary functions of potassium in the body are to maintain normal fluid balance and promote normal nerve and muscle function, research has also shown a direct link between adequate potassium intake and healthy blood pressure levels.
Clinicians at the University of Arkansas conducted a thorough review of the research on potassium and blood pressure. They report that potassium intake and blood pressure are correlated inversely; as intake goes up, blood pressure goes down (and vice versa). They found that people with severe hypertension experience the greatest benefit from increased potassium intake, and that this benefit was most pronounced with prolonged use. Finally, the researchers concluded that potassium should be part of the overall management of hypertension, or high blood pressure.
A recent study at the at the Chinese Academy of Medical Sciences appears to verify the above review findings. In a double-blind, randomized, placebo-controlled trial, researchers studied 150 men and women, aged 35 to 64 who were assigned either a potassium supplement or a placebo for 12 weeks. At both the six- and 12-week measurements, the participants taking potassium showed a significant reduction in blood pressure, leading researchers to conclude that potassium may play an important role in the prevention and treatment of high blood pressure.
The average healthy diet contains adequate potassium: meat, chicken, salmon, potatoes, bananas, orange juice and tomatoes are all good sources.
Sources: Am J Med Sci 1997 Jul;314(1):37-40; J Hypertens 2001 Jul;19(7):1325-31