It's been common knowledge that eating fruits and vegetables is good for you, but now there is yet another reason to eat your peas (or bananas). A new study from St. George's Medical School in London, published in the April 2005 issue of Hypertension, compared the blood-pressure-lowering effects of potassium chloride against the effects of potassium citrate. The results of this study showed that potassium citrate has the same blood-pressure-lowering effect as potassium chloride, which has been proven in the past to lower blood pressure. Potassium chloride, however, must be taken as a dietary supplement, whereas potassium citrate is found naturally in many foods.
The study tested the effects of potassium chloride and potassium citrate on 14 adults with an average starting blood pressure of 151/93, placing them in the category of Stage 1 hypertension. The volunteers were randomly split into two groups; one group was given potassium chloride daily for one week, while the other received potassium citrate. Then, following a one week break, the treatment groups were crossed over and received the opposite treatment for an additional week. While taking potassium chloride, volunteers had an average blood pressure of 140/88, and while on potassium citrate, it averaged at 138/88. The difference between the effects of the two types of potassium was not significant, meaning each had similarly beneficial effects on hypertension.
"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," write the researchers in their report. "Increasing the consumption of food high in potassium is likely to have the same effect on blood pressure as potassium chloride."
Rather than investing in a new dietary supplement, lowering your blood pressure may be as easy as watching what you eat. Foods high in potassium citrate include bananas, citrus fruit, dried apricots, fish (especially salmon, flounder, and tuna), green leafy vegetables, legumes, melons, potatoes, poultry, tomatoes, whole-grain cereals, and yogurt. So stock up on potassium-rich foods to help push your blood pressure down. But, before increasing your intake of potassium, check with your doctor. Some people — for example, those with kidney disease — may need to avoid both potassium and salt.
July 2005 Update