High blood pressure is a leading risk factor for disease development, especially of the heart and kidney. We have long known that populations who consume high amounts of sodium have higher blood pressures. Clinical studies indicate that lowering sodium intake in people who eat diets high in sodium and have high blood pressure helps reduce blood pressure. However, there is conflicting evidence and advice about blanket reductions in sodium intake and whether setting a target for sodium intake is beneficial or maybe even harmful for some people.
An alternate way to look at blood pressure and diet is to focus on potassium. Observational studies indicate that diets high in potassium are associated with lower blood pressure, regardless of sodium intake.
Potassium may be protective of blood pressure and counteract the negative effects of salt in the diet. In addition, diets low in potassium appear to increase the negative affects of sodium on blood pressure.
How does this work? Potassium acts like a control mechanism for sodium excretion in the kidney: more potassium in the blood causes sodium to be released into the urine, less potassium causes it to stay in the blood where it may increase blood pressure.
To protect yourself from the risks associated with high blood pressure, and to help reduce your blood pressure if you are already hypertensive, increase your intake of potassium rich foods. Fruits and vegetables tend to be rich sources of potassium and these foods provide many health protective compounds, so it may be that potassium is not the factor but simply a marker of a healthy diet. Regardless of the mechanism, observational studies point towards improving the ratio of potassium to sodium in the diet as a path for health.
How much do you need?
The recommended daily intake of potassium is 4.7 grams per day. That’s almost double what most of us actually consume. Potassium is found in a wide range of foods, but is particularly plentiful in dark green leafy vegetables, orange vegetables, and citrus.
- 1 cup cooked spinach: 840 milligrams
- 1 baked potato with skin: 926 milligrams
- 1 cup cooked broccoli: 460 milligrams
- 1 cup cantaloupe: 430 milligrams
- 1 medium tomato: 290 milligrams
- ½ cup strawberries: 125 milligrams
- 1 medium banana: 425 milligrams
- 6 ounces yogurt (plain or with fruit): 260 to 435 milligrams
Reach your recommended daily intake of potassium by frequently adding these foods to your daily menu (learn more at Shifting the Balance of Sodium to Potassium.).
We shouldn’t completely forget about sodium in the diet, however. One of the complicating factors with salty foods is that they tend to be highly processed; 75% of the sodium consumed in the US is added to our food during processing. Adding salt while cooking is one thing, regularly eating sodium laden processed foods with multiple synthetic additives, sugars, and refined carbohydrates is another. These foods harm our health in multiple ways and no amount of protective potassium is going to change that.
Read more in a recent meta-analysis of potassium intake and health in the February issue of The American Journal of Physiology.