Most Canadian adults don’t consume enough potassium, according to Health Canada. That’s not surprising, since fruits, vegetables, legumes (for example, beans and lentils) – foods that many people don’t eat enough of – are among the best sources.
And yet, Canadians would be smart to pay attention to the mineral: it helps to build muscle, transmit nerve impulses, maintain a normal heart rhythm and keep food moving through the digestive tract.
Consuming too little potassium has been linked to a greater risk of high blood pressure, heart attack, stroke, even osteoporosis. If you already have hypertension, boosting your intake of potassium-rich foods can help to lower your blood pressure.
Potassium is vital for muscle function. Your skeletal muscles and the smooth muscle that lines your blood vessels, stomach, intestines and bladder rely on a steady intake of potassium.
Potassium relaxes the walls of blood vessels, which can help avert muscle cramps and lower blood pressure.
Increasing your potassium intake may also diminish the blood-pressure-raising effect of a high-sodium diet. A 2017 study from Boston University of Medicine, conducted in 2,632 adults aged 30 to 64, found that people with high sodium intakes, who also consumed plenty of potassium, had the lowest blood-pressure readings.
When you consume more potassium, your kidneys excrete excess sodium through the urine.
If bananas are your go-to potassium food, it's time to think outside the box. Sure, one medium banana contains a hefty 422 milligrams of potassium – nearly 10 per cent of a day's worth – but there are many other foods that deliver even more potassium per serving.
Fruits, vegetables, legumes, yogurt, milk and seafood are generally good sources of the mineral.
Include a variety of potassium-rich foods in your diet to help consume 4,700 mg of the mineral each day. (Caveat: For people with kidney problems, consuming too much potassium can be harmful. Speak to your doctor about the right amount of potassium for your diet.)
The following foods deliver more potassium than a medium-sized banana, along with numerous other disease-fighting nutrients. (Oh, keep eating bananas, too.)
1. Acorn squash
How much potassium: 896 mg in one cup
Don’t retire this winter vegetable just yet. One cup of acorn squash, cooked, serves up 896 mg of potassium – nearly 20 per cent of a day’s worth – along with nine grams of fibre and a generous amount of magnesium and folate.
Add it to your diet: Add cubes of roasted acorn squash to green salads, whole grain pilafs, bean burritos, chili and stews. Blend pureed cooked squash into smoothies, and muffin and pancake batters. Serve slices of grilled acorn squash as a side dish.
2. Baked sweet potato
How much potassium: 855 mg in one large sweet potato
One large (180 grams) baked sweet potato, with skin, makes a considerable contribution to your daily potassium intake by providing 855 mg of the mineral. That’s two bananas’ worth.
It also supplies six grams of fibre, 35 mg of vitamin C and an impressive 20 mg of beta-carotene. (Research suggests that a daily intake of three to six mg of beta-carotene is needed to help protect against chronic disease.)
Add it to your diet: Enjoy sweet potato baked, roasted, grilled or mashed with a splash of freshly squeezed orange juice and dash of cinnamon. You’ll get more potassium if you eat the skin.
3. White beans
How much potassium: 753 mg in ¾ cup
Navy, cannellini (white kidney beans), great northern and baby lima beans pack in more potassium than most other beans – 753 mg every three-quarters of a cup. (Only adzuki beans outrank white beans with 918 mg potassium a serving.)
A serving of white beans (3/4 cup) also provides 13 grams of protein, 8.5 grams of fibre and 100 micrograms of folate, a B vitamin needed for DNA synthesis and repair. (Adults need 400 micrograms of folate each day.)
Add it to your diet: Include white beans in chili, soup and bean salad recipes, toss them into a green salad, or saute them with leafy greens for a vegetarian meal.
Puree white beans with roasted garlic and fresh thyme to make a bean dip for raw vegetables.
4. Beet greens
How much potassium: 654 mg in ½ cup
The next time you buy beets, don't discard their green, leafy tops. One-half cup of cooked beet greens has 654 mg of potassium, plus they're an outstanding source of beta-carotene and bone-building vitamin K.
One-half cup of beet greens also delivers a decent amount of calcium, magnesium and vitamin C. Not bad for 19 calories.
Add it to your diet: Add beet greens to omelettes, stir-fries, pasta sauces and curries. Toss raw beet greens into green salads. Use leftover steamed or blanched beet greens in smoothies and protein shakes.
5. Roasted soybeans
How much potassium: 652 mg in ¼ cup
Also called soy nuts, one-quarter cup of roasted soybeans offer 652 mg of potassium and a lot more. You also get calcium, magnesium, zinc, selenium, 16.5 grams of plant protein, 7.5 grams of fibre and 22 per cent of a day’s worth of folate.
Roasted soybeans are available flavoured, salted and unsalted at grocery and natural food stores. You can also roast your own after soaking and cooking dry soybeans.
Add it to your diet: Enjoy soy nuts as a nutritious snack or toss them into a salad for extra crunch.
How much potassium: 430 mg in two kiwi
Two small kiwifruit delivers a decent 430 mg of potassium along with four grams of fibre and more than a day's worth of vitamin C (128 mg).
Add it to your diet: Include kiwifruit in fruit smoothies (kiwifruit and strawberries make a tasty combo). Add sliced kiwifruit to fruit salads – include cantaloupe, too, another potassium-packed fruit.
How much potassium: 652–1,068 mg in six ounces
Along with its omega-3 fatty acids, six ounces of salmon provides anywhere from 652 to 1,068 mg of potassium, depending on the variety.
What's more, a six-ounce portion of Atlantic salmon, for example, has 894 international units of vitamin D and 70 micrograms of selenium, a mineral important for thyroid and immune function. (Adults require 55 micrograms of selenium a day.)
Haddock, halibut and tuna are also high in potassium.
The bottom line
Bananas are a good source of potassium – one medium banana has nearly 10 per cent of a day’s worth of the mineral – but many other food deliver even more potassium per serving. Try adding acorn squash, baked sweet potato, white beans, beet greens, roasted soybeans, kiwi and salmon to your diet, too. All these foods also provide a wealth of other health benefits and belong in a healthy diet.
Leslie Beck, a Toronto-based private practice dietitian, is director of food and nutrition at Medcan. Follow her on Twitter @LeslieBeckRD