High potassium foods protect against the effects of hypertension, as shown in many population studies. Although population studies may show the association between health and a high potassium sodium ratio, basic science studies need to confirm that it is the potassium sodium ratio that causes the improvement in health. This is how association becomes causation.
Hypertension Is A Sign Of Cellular Disease
It is important to realize that hypertension is not a disease, but a sign of a cellular disease. Correcting the potassium sodium ratio in the foods you eat can reduce the debilitating consequences of hypertension even before your blood pressure comes down. A recent article (1) is one of many that gives clues as to how this happens. It also shows some limits of blood pressure medicines. Blood pressure medicines have limited effectiveness because they may not correct important physiological disturbances, even when they reduce blood pressure.
The study looked at the mechanical function of the heart with different levels of potassium and sodium in the diet, and with a blood pressure lowering medicine, hydralazine. The study showed that even when there is no reduction in blood pressure, the left ventricle of the heart functions better with a better potassium sodium ratio. It functions better by filling with more blood during its relaxation phase, allowing it to be a better pump.
The study also showed that even though the medication reduced blood pressure, there was no improvement in the function of the ventricle. It did not fill or pump any better.
More Potassium Means Less Free Radicals
To find a possible reason for the results, the researchers looked at whether free radicals (ROS) had anything to do with it. The researchers found that the improved function from the dietary potassium was associated with less free radical activity in the heart cells. However, there was no reduction in free radical activity with the medication, even though the blood pressure was lower.
Other studies indicate that free radicals may directly reduce ventricular relaxation by blocking the pump that moves calcium from one compartment in the cell to another. The increase in potassium reduced free radicals in this study, as did vitamin C in another (2).
The researchers concluded that a higher potassium intake will improve ventricular relaxation and function by protecting against free radical activity. This will happen even in the absence of an improvement in blood pressure.
Basic science studies such as these help explain how the population studies have shown big drops in the incidence of heart failure, strokes and other debilitating consequences of hypertension. These big drops happen even though there are only relatively small drops in blood pressure through an entire population, such as in Finland and Japan.
To Find Tables Of Potassium In Food
To find tables with the sodium and potassium content of foods, please click the “Links to Food Potassium Tables” tab at the top of the page. It will list tables of foods by food category. To find a specific food, look in the appropriate food category. To find the potassium in broccoli, for example, click on the link to the vegetables table.
1. Protective effect of potassium against the hypertensive cardiac dysfunction: association with reactive oxygen species reduction. Matsui H, Shimosawa T, Uetake Y, Wang H, Ogura S, Kaneko T, Liu J, Ando K, Fujita T. Hypertension. 2006 Aug;48(2):225-31. Epub 2006 Jul 3.
2. Impaired endothelial regulation of ventricular relaxation in cardiac hypertrophy: role of reactive oxygen species and NADPH oxidase. MacCarthy PA, Grieve DJ, Li JM, Dunster C, Kelly FJ, Shah AM. Circulation. 2001 Dec 11;104(24):2967-74.