Eating for Potassium
This article addresses a thoughtful question that was submitted by one of our website participants. This person asked, “I was told my potassium levels are a little low and that I need to eat more potassium-rich foods, but I don’t know what this means. What foods should I eat to get more potassium?” This is an excellent question because low levels of potassium in the body can be a side effect of some cancer treatments.
Potassium and Cancer Care
Chemotherapy medications such as capecitabine (Xeloda®), cisplatin (Platinol®), oxaliplatin (Eloxatin®), erlotinib (Tarceva®), vinorelbine (Navelbine®), methotrexate, and others can cause low potassium (1-3). Treatments that cause vomiting and/or diarrhea also may lower the level of potassium and other minerals, such as sodium, in the body.
If potassium levels become very low, your health care provider may prescribe potassium supplements. However, for many people, simply eating more potassium-rich food is enough to improve potassium levels back into the normal range.
Key Roles for Potassium
Even beyond the importance of addressing low levels of potassium during cancer care, it is important for all people to get more potassium in the diet. The typical American diet often contains far too much sodium (salt) and not nearly enough potassium (4). Processed food contributes excess sodium to the diet and most of us do not eat enough of the healthy whole foods such as vegetables and fruit that are good sources of potassium.
Potassium has many important roles in maintaining health. Eating plenty of potassium rich foods on a daily basis appears to protect against hypertension, stroke, heart disease, and loss of bone mass with aging (5-8). Furthermore, potassium is important for proper muscle function and failing to get enough potassium may contribute to muscle cramps and an irregular heartbeat.
Getting More Potassium
The single best way to get more potassium into your diet is to eat more vegetables, fruit, whole grains, legumes (beans), nuts, and seeds. Most people think of bananas when they think of potassium, but this isn't the only potassium-rich food. Any vegetable, fruit, or bean will provide you with a good dose of potassium and many have more potassium even than bananas.
Along with these healthy foods, low-fat dairy products such as skim milk and non-fat yogurt are excellent sources of potassium. On a per serving basis, low-fat dairy provides more potassium than many other foods.
It’s About the Pattern
If you are feeling well, you are not losing weight, and you are not experiencing symptoms that interfere with your ability to eat normally, you should focus on a healthy diet to address your potassium needs. This means eating plenty of vegetables, fruit, whole grains, legumes (beans), nuts, and seeds. You may wonder, “How much is “plenty”? An easy approach for healthy eating is to follow the 75% - 25% principle.
Every time you eat, make sure that 75% (three-fourths) of your plate is covered by healthy plant food, including vegetables, fruit, whole grains, and legumes. The remaining 25% (one-fourth) should be covered by lean protein, such as fish, chicken, or lean beef. If you prefer to eat a more vegetarian diet, use legumes as your lean protein source.
Following the 75% - 25% principle will help you eat plenty of healthy food without getting bogged down in counting servings or tracking exactly what goes into your mouth. This type of diet is ideal for health and fortunately, provides plenty of potassium as well. Keep in mind, however, that this type of diet only is right for people who are feeling well and are not losing weight due to the side effects of cancer and its treatment.
If you are you are having difficulty maintaining your weight, be sure to talk to your health care team about how better to manage your symptoms and meet your nutrition needs. In addition to this, you can review our information on Symptom Support and Recipes for During Treatment to find more ideas on how to eat well during cancer care. Maintaining your weight is important because it will help you tolerate your treatments better and recover as quickly as possible.
Plants for Potassium
As mentioned above, plant foods, especially vegetables and fruit, are the best natural sources of potassium. But even among these foods, there are some superstars that can give you a big potassium boost. One of the best potassium-power foods is low sodium, tomato-based vegetable juice. The low sodium label is very important. Regular tomato juice contains excess sodium and most of us do not need more of this mineral! One eight ounce serving of low sodium tomato juice contains approximately 700 to 800 milligrams of potassium. That provides more than one-fifth of your daily needs.
Along with low sodium tomato juice, the best sources of potassium include white beans, dates, beet greens and other green leafy vegetables, raisins, potatoes, low-fat dairy foods, and orange juice. The food list below gives additional ideas for potassium-rich foods you can add to your diet (9)
High Potassium Food List
- Tomato juice (go for low sodium varieties)
- Beet greens (lightly cooked, not boiled)
- Beans, especially white beans
- Low fat dairy products (skim milk and no fat yogurt)
- Potatoes (regular and sweet)
- Orange juice
- Prune juice
- Carrots and carrot juice
- Whole grain flour, especially buckwheat flour
- Oat Bran
- Squash and pumpkin
Remember, these aren't the only foods that contain plenty of potassium. Nearly all plant foods will provide you with a good dose of this important mineral.
- Saif MW, Fekrazad MH, Ledbetter L,Diasio RB Ther Clin Risk Manag. 2007;3(1):177–180. Hypokalemia secondary to capecitabine: a hidden toxicity?
- Davies AM, Ho C, Hesketh PJ, Beckett LA, Lara PN Jr, Lau DH, Gandara DR. Erlotinib and vinorelbine in advanced malignant solid tumors: a phase I study. Invest New Drugs. 2007;25(4):351-55.
- Kintzel PE. Anticancer drug-induced kidney disorders. Drug Saf. 2001;24(1):19-38.
- Frassetto LA, Morris RC Jr, Sellmeyer DE, Sebastian A. Adverse effects of sodium chloride on bone in the aging human population resulting from habitual consumption of typical American diets. J Nutr. 2008;138(2):419S-422S.
- Lanham-New SA. The balance of bone health: tipping the scales in favor of potassium-rich, bicarbonate-rich foods. J Nutr. 2008;138(1):172S-177S.
- Fung TT, Chiuve SE, McCullough ML, Rexrode KM, Logroscino G, Hu FB. Adherence to a DASH-style diet and risk of coronary heart disease and stroke in women. Arch Intern Med. 2008;168(7):713-20.
- Ignarro LJ, Balestrieri ML, Napoli C. Nutrition, physical activity, and cardiovascular disease: an update. Cardiovasc Res. 2007;73(2):326-40.
- Matsui H, Shimosawa T, Uetake Y, Wang H, Ogura S, Kaneko T, Liu J, Ando K, Fujita T. Protective effect of potassium against the hypertensive cardiac dysfunction: association with reactive oxygen species reduction. Hypertension. 2006;48(2):225-31.
- USDA Agricultural Research Service. National Nutrient Database for Standard Reference, Release 20, Nutrient Lists. Available at: http://www.ars.usda.gov/Main/docs.htm?docid=15869. Accessed May 15, 2008.
Date Posted: May 2008
This content was last reviewed
August 15, 2010 by Dr. Reshma L. Mahtani.