Dear Doctor: Your recent column about how potassium can help lower blood pressure was quite helpful, but when I looked into supplements, they turned out to be almost useless. Why is that? What foods should I be eating?
Dear Reader: Potassium is a mineral that plays a key role in the optimal functioning of nerves, muscles, fluid balance, and, as we wrote about recently, the regulation of blood pressure. Although it’s found in a wide range of whole foods, Americans’ ongoing love affair with highly processed and fast foods has led to diets that fall short of adequate potassium.
The most recent guidelines for daily potassium intake were released last March by the National Academies of Science, Engineering and Medicine. They recommend a minimum of 2,300 milligrams per day for healthy women, and 3,400 mg per day for healthy men. These newest recommendations are lower than those previously established in 2005.
Unfortunately, according to the National Institutes of Health, the majority of Americans get less than half the amount of the mineral that they need. It seems logical that, since you can boost your intake of just about any vitamin or mineral with a supplement, you should be able to do the same with potassium. However, it’s not that simple. Potassium has the potential to interact with a variety of medications, including blood pressure meds, diuretics and some common pain medications. Depending on the specific medication, it can result in potassium levels that are dangerously high or dangerously low. Too much or too little potassium can lead to muscle cramping, nerve problems, problems with cognition and potentially life-threatening heart arrhythmias. As a result, the U.S. Food and Drug Administration requires over-the-counter potassium supplements, including multivitamins, to contain less than 100 mg, which is a fraction of the recommended daily intake.
The good news is that by eating a diet that draws from a wide variety of whole and fresh foods, you can meet your daily potassium needs. Foods that contain high or moderate levels of potassium include fish like salmon, tuna, cod and snapper; most red meats; leafy greens like spinach and chard; black beans, pinto beans and white beans; avocados; bananas; apricots; potatoes; tomato sauce and tomato paste; watermelon; lentils; cantaloupe; yogurt; and coconut water. One quick and easy way to give a meal a potassium boost is with frozen spinach, which can easily be added to soups and stews and used as a side dish. Beans, beets and avocados make great additions to salads. Try swapping out sweet or salty ultra-processed snacks for cantaloupe or watermelon.
While you’re busy revving up your potassium intake, don’t forget to continue to be vigilant about salt. The American Heart Association wants adults to eat no more than 2,300 mg of sodium per day, and recommends we stick closer to a limit of 1,500 mg per day — or less. This is particularly important for people dealing with high blood pressure, or those who are at risk of cardiovascular disease.
Although getting enough potassium without the help of supplements may seem daunting at first, deliberate food choices and just a bit of advance planning will get you into the zone.
Dr. Eve Glazier, M.D., MBA, is an internist and associate professor of medicine at UCLA Health.