Yes, bananas have a lot of potassium—here’s why that matters
by Emily Laurence
Raise your hand if the only thing you know about potassium is that bananas have lots of it. (Not just me? Okay, cool.)
Consider this your nutrition lesson for the day: Potassium is a mineral that the body needs to function properly—it helps muscles contract and plays a role in regulating your body’s fluid levels and blood pressure. Most people get enough potassium, per the National Institutes of Health (which for women, is about 2,300 milligrams per day), which is good because a deficiency can have some serious consequences. “Low potassium levels create an acidic environment in the blood causing increased bone turnover and bone weakness,” says Allison Aaron, RD, CN. “Potassium deficiency may impair kidney function, causing excessive urination and the formation of kidney stones as well as elevated blood glucose due to impaired carbohydrate metabolism.”
Okay cool, but what does potassium actually do for the body? Can you get too much or can you eat 51 bananas a day and still be good? Aaron answers all of your burning potassium questions below.
What are the main potassium benefits?
1. Potassium balances out sodium. “Potassium’s main job is to balance sodium levels so that the body can function properly,” Aaron explains. “Having the right potassium-sodium ratio is important for electrolyte balance, which is essential for proper muscle contraction and nerve transmission, fluid balance—which promotes normal blood pressure—and acid-base balance for preservation of bone strength.” Potassium and sodium are both needed for the body to maintain proper fluid and blood levels; it’s important to get adequate amounts of both. But if you have too much sodium and not enough potassium, you’re at risk for your blood pressure rising to unhealthy levels, which is bad for your heart.
2. Potassium helps your body digest carbs. Aaron says the mineral helps convert the glucose in carbohydrates into energy. That’s exactly why so many athletes make sure to get enough before or after they work out.
3. It could lower your risk for stroke and heart disease. Remember how potassium helps keep blood pressure down? That’s great news for your cardiovascular system. Scientific evidence links regular potassium consumption with lowered risk for stroke and coronary heart disease.
How can I get more potassium in my life?
Easy—just eat foods high in potassium. While bananas are often touted as a potassium powerhouse—and with 422 milligrams per medium fruit, it does have a decent amount—it’s not the only good source. Two cups of spinach has 334 milligrams of potassium, one cup of Brussels sprouts has 389 milligrams, and one cup of lentils has a whopping 731 milligrams.
If you do want to stick with fruits, one cup of cubed cantaloupe has 427 milligrams, one cup of dried apricots has 1,720 (!) milligrams, and one cup of oranges has 326 milligrams—making them all great sources.
However, while loading up on potassium-rich foods is generally not an issue for most healthy people, getting too much potassium can be a problem for people who have kidney issues, Aaron says. Your body’s potassium is processed in the kidneys; if your kidneys aren’t working properly, your body might have a hard time filtering out the excess. “Those with impaired kidney function should consult their doctor about going on a potassium-restricted diet if potassium build-up is a concern,” Aaron says.
It’s clear that potassium is vastly important to the body, and fortunately, it’s not too hard to get enough of this vital nutrient—and doing so can be delicious! If you are worried about your potassium levels, book an appointment with your doctor who can do blood work ensuring your levels are where they should be. And hey, maybe pack a banana to eat on your way home.