High potassium foods protect against hypertension, osteoporosis, and kidney stones, as shown in multiple studies. Also, people eating high potassium foods have less cardiovascular disease and other heart problems. Doctors know well that a poor potassium level can cause arrhythmias (irregular heart beats) in the heart. However, few doctors know that a poor potassium level can also reduce the heart's mechanical function – its ability to pump blood. And even fewer of them know that the poor potassium level results in increased free radical formation.
How Does A Poor Potassium Sodium Ratio Cause Heart Problems?
Dr. Young in an editorial (1) from 2006 discusses the implications of the article we discussed in the last post. Animal and human studies show that too high a level of sodium, or too low a level of potassium, causes the ventricle to function poorly. Specifically, this is because the ventricle does not relax as fully, or as fast, as when potassium and sodium are at a proper level. As a result, the ventricle does not fill with blood, and less blood pumped through the blood vessels.
In the article discussed in the last post, this decreased function of the ventricle from inadequate potassium had an association with increased free radical (ROS) formation. In 1992 Dr. Young showed that improved potassium levels reduce free radical levels in the cell.
Free Radical Formation May Be The Cause
In this editorial he ties together the evidence about increased free radical formation being the possible cause of this reduced heart function. He cites several other studies consistent with this theory. One showed that vitamin C (an antioxidant) improved heart diastolic function. Two other studies connected how the free radicals could interfere with calcium movement in cells, thus interfering with the ventricle's ability to relax and fill with blood.
The worsening of diastolic function is one of the earliest abnormalities in heart function from inadequate potassium. It occurs before there is any abnormality in the systolic (when the heart contracts) function. This improvement in the diastolic function from potassium occurs even before blood pressure is lowered.
Thus, more and more studies are filling in the blanks on how an improved potassium sodium ratio improves heart function. The question is not whether a high ratio improves heart function. That is well established. But the question is how. What are the mechanisms the cell uses to bring about these improvements? And how do the mechanisms work? Each study confirms the basic finding that a high potassium to sodium ratio in the diet helps the heart.
Although Dr. Young wrote the editorial in consideration of the use of potassium supplements to improve the potassium level in the blood, it is high potassium foods that best improve the potassium level in the body.
Tables Of High Potassium Foods
To find tables of high potassium foods, please look under the “Links to Food Potassium Tables” tab at the top of the page.
1. Potassium depletion and diastolic dysfunction. Young DB. Hypertension. 2006 Aug;48(2):201-2. Epub 2006 Jul 3.