Name: The Banana Is Not Your Best Potassium Source
Creator: Gary Menichini
Published: May 28, 2026

What the evidence actually says

A banana is a decent snack and a middling potassium source. A potato baked in its skin carries more than twice as much, and most Americans are short of the daily target whichever one they reach for.

1952 mg · a medium russet potato baked in its skin, per Harvard Health
2422 mg · a medium banana, less than half the potato
33,400 and 2,600 mg · the daily targets for adult men and adult women
4Skin on · a fair amount of the mineral sits in or just beneath it
5Sodium counts · the ratio matters as much as the potassium itself

Ask anyone where to find potassium and you will hear the same answer. The banana has held that job in the public imagination for decades, largely on the strength of being yellow, portable and heavily marketed. It is not a bad food. It is simply not the strongest thing in the produce aisle, and it is not particularly close.

Harvard Health opens its own guide with the correction: bananas are just the beginning, and almost every food in the plant kingdom, from potatoes to papayas, supplies some amount of potassium. The interesting question is not whether bananas count. It is why nutrition experts have flagged this mineral as a nutrient of public health concern in the first place.

The comparison

The Potato Wins, and Not Narrowly

The numbers settle it quickly. In the food table Harvard Health publishes from USDA FoodData Central, a medium russet potato baked with the skin on carries about 952 mg of potassium. A medium banana carries 422 mg. That is a gap of more than two to one in a single serving, and the potato is not even an exotic ingredient.

The rest of the table rearranges the whole mental picture. Half a cup of cooked beet greens comes in at about 655 mg. A baked sweet potato with skin, about 542 mg. Three ounces of cooked wild Atlantic salmon, about 534 mg. A cup of plain low fat yogurt, about 531 mg. Half a cup of cooked white beans, about 500 mg. Every one of those beats the banana, and most people would not have guessed a single one of them.

Harvard Health's specific instruction about potatoes is worth repeating because it is easy to lose: a fair amount of the mineral, along with some fiber, sits in or just beneath the skin. Peeling the potato throws away part of the reason you cooked it.

The gap

Why Almost Everyone Falls Short

The target is not obscure. The NIH Office of Dietary Supplements puts the daily adequate intake at 3,400 mg for adult men and 2,600 mg for adult women, and states plainly that the diets of many people in the United States provide less than recommended amounts. Even when food and supplements are combined, total intakes for most people sit below the recommendation.

Harvard Health's Teresa Fung, adjunct professor of nutrition at Harvard's T.H. Chan School of Public Health, names the cause without hedging. People are not eating enough fruits and vegetables, and especially legumes. Compounding it, she says, the modern American diet leans heavily on ultra processed foods, which are typically low in potassium and high in sodium, the exact opposite of what the body needs.

Baked potatoes split open in their skins on brown paper — Harvard Health puts a medium russet baked in its skin at about 952 mg of potassium. A fair amount sits in or just beneath the skin.

The mechanism

What Potassium Does to Blood Pressure

Harvard Health describes the mechanism in two moves. Potassium helps relax blood vessel walls, and it signals the kidneys to excrete excess sodium. Both lower blood pressure, which is what connects the mineral to a reduced risk of stroke and cardiovascular disease. It also works alongside sodium to generate the electrical signals that let muscles, including the heart, contract and relax.

CDC states the practical version: increasing potassium intake can help decrease your blood pressure if you have high blood pressure, and by lowering blood pressure it can also reduce your risk for heart disease and stroke. CDC is careful to present sodium and potassium as a pair rather than a single lever, because most Americans eat too much of one and too little of the other.

The NIH Office of Dietary Supplements adds the consequences of running low over time: too little potassium can increase blood pressure, deplete calcium in bones, and increase the risk of kidney stones. People with low intakes have an increased risk of developing high blood pressure, especially if their diet is high in salt.

The better sources

Where the Real Potassium Lives

Fung's single most effective strategy, as reported by Harvard Health, is to eat more whole, minimally processed foods, particularly fruits, vegetables and legumes. Her specific advice is unusually concrete. Get in the legume habit, because beans, peas and lentils are high potassium and also supply protein and filling fiber, and a half cup serving is not hard to do. Canned beans make it easier.

Enjoy potatoes and sweet potatoes simply cooked and skin on, which she immediately qualifies: we are not talking about French fries or potato chips. Eat more dark leafy greens, because beet greens, Swiss chard and spinach all rank among the top sources per serving. Increase dairy and fish, many of which are potassium rich. And where fruit juice or dried fruit is concerned, go easy, because juice is high in sugar even when it is natural and drying concentrates sugars and calories.

The NIH fact sheet reaches the same place from a different direction, listing fruits such as dried apricots, prunes, raisins and orange juice; vegetables such as acorn squash, potatoes, spinach, tomatoes and broccoli; lentils, kidney beans, soybeans and nuts; milk and yogurt; and meats, poultry and fish. Note how little of that list is a supplement. Most potassium pills provide no more than 99 mg per serving, a rounding error against a 3,400 mg target.

Cooked lentils in a dark pan with red pepper and fresh parsley — Half a cup of cooked lentils carries about 365 mg of potassium, and white beans about 500 mg, alongside protein and fiber.

Potassium from food has not been shown to cause harm in healthy people with normal kidney function.

The NIH Office of Dietary Supplements is equally clear about the exception: people with chronic kidney disease, and those taking ACE inhibitors or potassium sparing diuretics, can develop dangerously high blood potassium even on ordinary intakes. For them this advice runs backwards.

NIH Office of Dietary Supplements

The honest limit

Who Should Not Chase This

Almost every article about a nutrient stops at the good news. This one should not, because the exception here is genuinely dangerous rather than theoretical. The NIH Office of Dietary Supplements states that excess potassium is eliminated in the urine in healthy people, but that people with chronic kidney disease and those who use certain medications can develop hyperkalemia, abnormally high blood potassium, even when they consume typical amounts from food.

The medications named are common ones: ACE inhibitors such as benazepril, angiotensin receptor blockers such as losartan, and potassium sparing diuretics such as amiloride and spironolactone. All of them reduce how much potassium you lose in urine. Hyperkalemia can also develop in people with type 1 diabetes, congestive heart failure, liver disease or adrenal insufficiency.

Salt substitutes deserve their own warning for the same reason. NIH notes that potassium is an ingredient in many products used to replace table salt, and that for someone with kidney disease or on certain medications these can push potassium levels too high. Anyone in those groups should ask a healthcare provider how much potassium is safe for them before changing anything, rather than treating a food list as universal advice.

Fresh spinach leaves with water droplets — Harvard Health ranks beet greens, Swiss chard and spinach among the top potassium sources per serving.

Take the potassium swap sheet with you

Your free 2-page guide: the foods that carry real potassium per serving, the sodium half of the equation, and who should check with a doctor first.

One email. No spam. Unsubscribe anytime.

📋 Your Coach's Recommendations

Put a Legume on the Plate Most Days

Harvard Health's Teresa Fung calls legumes the gap most people are missing, and says a half cup serving is not hard to do. Half a cup of cooked white beans carries about 500 mg of potassium, edamame about 485 mg, lentils about 365 mg, plus protein and fiber. Canned beans count. Add them to soups, salads, tacos and pasta.

Cook the Potato, Keep the Skin, Skip the Fryer

A medium russet baked in its skin is the single biggest per serving hit in Harvard Health's table at about 952 mg, and a baked sweet potato with skin brings about 542 mg. Harvard notes a fair amount of the mineral sits in or just beneath the skin. Fung's caveat is explicit: this does not mean French fries or potato chips.

Fix the Sodium Side of the Ratio Too

CDC frames this as a pair, not a single nutrient. Americans average more than 3,400 mg of sodium a day against a federal recommendation of less than 2,300 mg, and most of it arrives in packaged and restaurant food. CDC suggests the DASH eating plan, which is low in sodium and high in potassium rich fruits, vegetables and low fat dairy.

How it works. Just a quiet check-in, not an alert and not a recurring nag. The event lands as a 30-minute slot at 9am two weeks from today, with your plan in the notes and a link back to this article. Works with Apple Calendar, Google Calendar, and Outlook. Yours to move, snooze, or delete whenever.

Keep this plan

Get the 2-page guide: what to swap, and the one group this advice does not fit.

One email. No spam. Unsubscribe anytime.

Where should we send it?

Your potassium swap sheet, straight to your inbox.

We send the plan plus one short evidence brief each week. Unsubscribe anytime.

✓

It is on the way

Check your inbox in the next minute. Want it right now?

⬇ Download your plan (PDF)

Your first Ageless Brief arrives this week: one study, translated, no hype.

To your health,

Frequently Asked Questions

Is a banana a bad source of potassium?

No, just an overrated one. Harvard Health's table puts a medium banana at 422 mg, which is a real contribution toward a 2,600 to 3,400 mg daily target. It is simply beaten by a baked potato with skin at about 952 mg, beet greens at about 655 mg per half cup, a baked sweet potato at about 542 mg, and several dairy and fish servings.

How much potassium do I actually need each day?

The NIH Office of Dietary Supplements lists the adequate intake as 3,400 mg a day for men aged 19 and over and 2,600 mg for women, rising to 2,900 mg in pregnancy and 2,800 mg while breastfeeding. It also states that the diets of many people in the United States provide less than the recommended amount.

Will eating more potassium lower my blood pressure?

CDC says increasing potassium intake can help decrease your blood pressure if you have high blood pressure, and that by lowering blood pressure it can also reduce your risk for heart disease and stroke. CDC treats it as one half of a pair with sodium, which most Americans eat too much of, averaging more than 3,400 mg a day against a recommended limit below 2,300 mg.

Should I take a potassium supplement instead?

For most people that is not where the gap gets closed. The NIH fact sheet notes that most dietary supplements provide no more than 99 mg of potassium per serving, which is small against the daily target, and that people should get most of their nutrients from food and beverages. Anyone with kidney disease or on blood pressure medication should speak to a provider before supplementing.

Can too much potassium be dangerous?

From food, not in healthy people with normal kidney function, because the excess leaves in urine. But the NIH Office of Dietary Supplements warns that people with chronic kidney disease and those taking ACE inhibitors or potassium sparing diuretics can develop hyperkalemia even at typical intakes. Salt substitutes carry the same risk for those groups because potassium is a common ingredient in them.

Is this medical advice?

No. This article is educational and is not a substitute for care from your doctor. If you have kidney disease, heart failure, diabetes or take blood pressure medication, ask a healthcare professional how much potassium is safe for you before changing your diet.

Curious where you stand? Take the free 5-minute lifestyle assessment and your personal scorecard appears the second you finish.

By the Ageless Coach Editorial Team · Published May 28, 2026 · Last updated July 21, 2026

The Banana Is Not Your Best Potassium Source

A banana is a decent snack and a middling potassium source. A potato baked in its skin carries more than twice as much, and most Americans are short of the daily target whichever one they reach for.

The Potato Wins, and Not Narrowly

Why Almost Everyone Falls Short

What Potassium Does to Blood Pressure

Where the Real Potassium Lives

Who Should Not Chase This

Take the potassium swap sheet with you

How Healthy Is Your Current Lifestyle?

Keep this plan

Where should we send it?

It is on the way

Frequently Asked Questions

Subscribe to the Free Newsletter

Share this Article:

Your Coach's Plan

More Science. Less Noise.