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Potassium: An Essential but Often Overlooked Nutrient

Worst Pills, Best Pills Newsletter article November, 2021

Most Americans are appropriately aware of the harmful effects of high sodium intake, commonly associated with a modern Western diet that emphasizes heavily processed foods such as frozen pizza and microwaveable dinners.

However, fewer individuals realize that adequate potassium intake is beneficial to the body and that the modern Western diet tends to be markedly deficient in this vital mineral.

In fact, the Dietary Guidelines for Americans classifies potassium as a “nutrient of public...

Most Americans are appropriately aware of the harmful effects of high sodium intake, commonly associated with a modern Western diet that emphasizes heavily processed foods such as frozen pizza and microwaveable dinners.

However, fewer individuals realize that adequate potassium intake is beneficial to the body and that the modern Western diet tends to be markedly deficient in this vital mineral.

In fact, the Dietary Guidelines for Americans classifies potassium as a “nutrient of public health concern” because it is generally underconsumed by various U.S. population groups, leading to health problems.[1]

Learn about the benefits of potassium and some of its rich dietary sources to incorporate into your diet.

About potassium

Potassium is critical for human health.[2] It is present in all body tissues and is required for normal cell function because it maintains fluid volume in the cells. It also plays a role in proper kidney function, muscle contraction and nerve transmission.

Furthermore, higher potassium intake may decrease blood pressure and is associated with reducing the risk of stroke, partly because it dilates blood vessels and increases the excretion of sodium by the kidneys into the urine.[3] In fact, the Food and Drug Administration (FDA) has approved a health claim that states that “[d]iets containing foods that are good sources of potassium and low in sodium may reduce the risk of high blood pressure and stroke.”[4]

Therefore, the Dietary Approaches to Stop Hypertension diet (commonly known as the “DASH” diet), which is high in potassium and other nutrients (including calcium and magnesium) and low in sodium,[5] is recommended as a key lifestyle modification for individuals with hypertension or other cardiovascular disease risk factors.[6]

Research evidence also suggests that adequate dietary potassium is associated with increased bone mineral density and improved kidney function.[7]

Adequate potassium intake and dietary sources

The 2019 guidelines from the National Academies of Sciences, Engineering, and Medicine specify that adequate daily intake of potassium is 3,400 milligrams (mg) for healthy adult males and 2,600 mg for healthy nonpregnant and nonlactating adult females.[8],[9]

Importantly, consuming higher amounts of potassium than those specified in the guidelines is mostly safe in adults with normal kidney function because excess potassium is generally flushed out in the urine.

The best way to increase potassium intake is by consuming potassium-rich foods and beverages. Fortunately, potassium is present in a wide range of plant and animal foods.[10] Particularly, many fruits and vegetables as well as some legumes are excellent sources of potassium (see Table below for examples of good dietary sources of potassium). Note that many of these foods also are rich in calcium, fiber and other nutrients as well, which provide additional health benefits.

Because Americans often do not get the recommended amount of potassium from foods, the FDA started requiring packaged food to list potassium content on their labels in 2018.[11]

Examples of Healthful Food Sources of Potassium and Their Potassium Content[12]

Food Standard Portion Potassium in Milligrams
Beet greens, cooked 1 cup 1,309
Lima beans, cooked 1 cup 969
Swiss chard, cooked 1 cup 961
Potato, baked, with skin 1 medium 926
Yam, cooked 1 cup 911
Acorn squash, cooked 1 cup 896
Amaranth leaves, cooked 1 cup 846
Spinach, cooked 1 cup 839
Water chestnuts 1 cup 724
Prune juice, 100% 1 cup 707
Carrot juice, 100% 1 cup 689
Yogurt, plain, nonfat 8 ounces 625
Adzuki beans, cooked ½ cup 612
Butternut squash, cooked 1 cup 582
Sweet potato, cooked 1 cup 572
Clams 3 ounces 534
Banana 1 medium 451
Skipjack tuna 3 ounces 444
Apricots, dried ¼ cup 378
Lentils, cooked ½ cup 366
Avocado ½ cup 364

Important considerations

Although high potassium intake is generally safe in healthy individuals, it can lead to excessive potassium concentrations in the blood (hyperkalemia) in individuals with impaired potassium excretion due to kidney disease.

Certain blood pressure medications also can cause hyperkalemia.[13] These medications are angiotensin-converting enzyme inhibitors (including benazepril [LOTENSIN] and lisinopril [PRINIVIL, QBRELIS, ZESTRIL]), angiotensin receptor blockers (including irbesartan [AVAPRO] and losartan [COZAAR]) and potassium-sparing diuretics (water pills, including amiloride [MIDAMOR] and spironolactone [ALDACTONE, CAROSPIR]). Sudden or severe hyperkalemia can cause heart rhythm disorders, which can be life-threatening.

In contrast, loop diuretics (including furosemide [LASIX]) and thiazide diuretics (including chlorothiazide [DIURIL]) can increase the amount of potassium lost in the urine, leading to abnormally low levels of potassium in the blood (hypokalemia).

What You Can Do

Unless you have certain health conditions or take certain blood pressure mediations that cause hyperkalemia, try to consume at least adequate amounts of dietary potassium from unprocessed, healthful dietary sources such as those mentioned in this article.

Eating more dietary potassium should be combined with efforts to avoid excess salt and develop other healthy eating and lifestyle habits.

Do not use salt substitutes or take over-the-counter potassium supplements without consulting your doctor because these products can cause hyperkalemia in certain patients.
 



References

[1] U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025. 9th Edition. December 2020. https://www.dietaryguidelines.gov/sites/default/files/2020-12/Dietary_Guidelines_for_Americans_2020-2025.pdf. Accessed September 7, 2021.

[2] National Institutes of Health, Office of Dietary Supplements. Potassium. Fact sheet for health professionals. March 26, 2021. https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/. Accessed September 7, 2021.

[3] Ibid.

[4] Food and Drug Administration. Health claim notification for potassium containing foods. October 31, 2000. https://www.fda.gov/food/food-labeling-nutrition/health-claim-notification-potassium-containing-foods. Accessed September 7, 2021.

[5] National Institutes of Health; National Heart, Lung, and Blood Institute. DASH eating plan. https://www.nhlbi.nih.gov/health-topics/dash-eating-plan. Accessed September 7, 2021.

[6] Staruschenko A. Beneficial effects of high potassium: Contribution of renal basolateral K+ channels. Hypertension. 2018;71(6):1015-1022.

[7] Weaver CM. Potassium and health. Adv Nutr. 2013;4(3):368S-377S.

[8] The National Academies of Sciences, Engineering, and Medicine. Consensus Study Report Highlights: Dietary Reference Intakes for Sodium and Potassium. March 5, 2019. https://www.nap.edu/resource/25353/030519DRISodiumPotassium.pdf. Accessed September 7, 2021.

[9] National Institutes of Health, Office of Dietary Supplements. Potassium. Fact sheet for health professionals. March 26, 2021. https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/. Accessed September 7, 2021.

[10] Ibid.

[11] Food and Drug Administration. The new and improved nutrition facts label – Key changes. January 2018. https://www.fda.gov/media/99331/download. Accessed September 7, 2021.

[12] U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary guidelines for Americans. Food sources for potassium. December 2020. https://www.dietaryguidelines.gov/food-sources-potassium. Accessed September 7, 2021.

[13] National Institutes of Health, Office of Dietary Supplements. Potassium. Fact sheet for health professionals. March 26, 2021. https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/. Accessed September 7, 2021.