A Banana a Day: New Study Suggests Potassium Helps Lower Blood Pressure

Can eating potassium-rich foods like bananas help keep hypertension in check? According to a new study, eating a diet rich in potassium seems to counteract the effect of foods with too much salt on blood pressure.  

Almost 50 percent of American adults have high blood pressure. Hypertension is a leading cause of heart disease and premature death, as it’s well documented that high blood pressure raises the risk for heart attack, stroke, aneurysm, kidney disease, vision issues, metabolic syndrome and dementia.  

If your blood pressure is consistently 130/80 mm Hg or higher, there’s a good chance your doctor has advised you to cut back on salt. Salt promotes water retention, which can increase blood fluid volume and raise blood pressure. For many people, this is easier said than done since the typical American consumes more than 3,300 mg of sodium every day – well above the recommended daily intake 2,300 mg. In response to this dilemma, the U.S. National Institutes of Health (NIH) to develop the lower-salt DASH diet in 1992. 

But from a nutritional standpoint, lowering salt is only half the solution, according to a study published in American Journal of Physiology Renal Physiology. In the near future, doctors may be asking patients to also increase their potassium intake. Sodium contributes to healthy cellular and nerve function, improves circulation and manages the body’s water storage.  

Too much salt leads to fluid retention, greater blood volume and higher blood pressure. Potassium, on the other hand, helps manage heart muscle and nerve function; decreases the risk of arrhythmia (irregular heart rate or rhythm); may help lower cholesterol; and acts as a diuretic agent, decreasing blood volume and the risk for stroke, particularly ischemic stroke.  

University of Waterloo researchers recently used a cutting-edge computation model to decipher how our bodies balance sodium, potassium and fluids, which is crucial to regulating blood pressure. The stimulation showed:  

• A handful of systems – renal (kidneys), cardiovascular, digestive and endocrine (hormones) – work together to properly balance fluids with sodium and potassium, two electrolytes that maintain appropriate blood volume.  
• Men and women respond differently to increases in potassium.
• Men tend to develop high blood pressure more often than premenopausal women.  
• Doubling your dietary sodium intake will slightly raise blood sodium levels but increase blood pressure, especially in men.
• Women experience a less extreme spike in blood pressure after consuming excess sodium because the macula densa -- an area of the kidney dense with specialized cells that function as a sensor in women, prohibiting reabsorption of sodium and promoting relaxation of blood vessels, helping to lower blood pressure.    
• A balance between sodium and potassium is important. It’s more about adding potassium rich foods to your diet than cutting sodium.        

Potassium’s role in blood pressure became a little clearer a few years ago after researchers from Keck School of Medicine, University of Southern California looked at the effects salt and potassium had on blood pressures of several populations and rodents. Researchers found that, while reducing salt intake is important for lowering blood pressure, increasing the intake of dietary potassium may have an equally important effect on blood pressure, according to a study published in the April 2017 issue of the American Journal of Physiology -- Endocrinology and Metabolism.  

Generally, adult women need 2,600 mg of potassium each day and men need 3,400 mg. You can get potassium requirements from your diet. Good sources include:

• Beans/lentils: lentils, lima, navy (baked), lima, peas (dried)
• Fruits: apricots, avocadoes, bananas, cantaloupe, nectarines, oranges, raisins, tomatoes
• Meat/poultry: beef (ground), turkey
• Nuts/Seeds: almonds, cashews, hazelnuts, pumpkin seeds, sunflower seeds
• Seafood: haddock, perch, salmon
• Vegetables: broccoli, Brussels sprouts, spinach, sweet potatoes, white potatoes
• Potassium supplements exist, but you should discuss them with your physician before taking them. Too much potassium raises the risk of:
• Kidney damage and possible kidney failure
• Muscular weakness and possible temporary paralysis
• Red blood cell and tissue damage
• Abnormal heart rhythm (cardiac arrhythmia), which can lead to a cardiac arrest

If you need help controlling your blood pressure, work with your MDVIP-affiliated doctor. A study published in the International Journal of Person-Centered Medicine showed that patients in MDVIP-affiliated practices better managed high blood pressure than patients in traditional practices.  

Moreover, MDVIP-affiliated doctors have the time to really get to know their patients, enabling them to customize a wellness plan for you and your needs. Don’t have an MDVIP-affiliated doctor? Find one near you by clicking here.