Is banana good source of potassium?
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Executive summary
Bananas are a reliable, convenient source of potassium — a medium banana typically provides roughly 420–450 mg of potassium, supplying about 10–15% of many adults’ daily needs [1] [2] [3]. They are useful for quick electrolyte replacement and as part of heart-healthy eating, but they are not the most potassium-dense food and other everyday foods deliver more potassium per serving [4] [5] [6].
1. What the numbers say: how much potassium is in a banana?
Multiple nutrition references put a medium banana in the 420–450 mg range: EatingWell cites ~420 mg [1], the University of Michigan patient handout lists 425 mg [2], and Harvard’s Nutrition Source lists about 450 mg per medium banana [3], so while exact figures vary by database and fruit size, the consensus in the reporting is clear that a single banana is a meaningful single-serving source of potassium [1] [2] [3].
2. Why potassium matters and where bananas help biologically
Potassium is an essential electrolyte that supports nerve signalling, muscle contraction including the heart, and helps the body excrete excess sodium — functions that link dietary potassium to blood‑pressure management and reduced strain on blood vessels [1] [3] [7]. For quick, portable potassium repletion after activity, illness, or during gastrointestinal fluid loss, bananas have historically been recommended because they are easy to eat and gentle on the stomach [3].
3. Put in perspective: bananas versus other potassium-rich foods
Health reporting repeatedly notes that many foods contain equal or greater potassium than a banana: cooked Swiss chard, yams, white beans and certain potatoes can deliver two times the potassium of a medium banana per comparable serving [4] [5]. Other contenders named across sources include dark leafy greens, avocados, potatoes, beans, and certain fish — and even some citrus and melon servings can rival or exceed banana amounts depending on portion and database used [4] [8] [5] [9] [7].
4. Practical dietary advice: use bananas as one tool, not the only one
Because the U.S. dietary guidance tables and clinical nutrition resources emphasize variety, the most reliable way to meet potassium targets is a mix of fruits, vegetables, legumes, dairy and some fish rather than relying on one food [7] [10]. For people watching carbohydrates, diabetes-oriented reporting points out low‑carb, potassium‑dense choices like spinach and avocado as practical alternatives to bananas [8]. Health writers and dietitians in these sources therefore recommend including bananas for convenience and taste, while encouraging other higher‑potassium options to reach daily goals [4] [5].
5. Conflicting emphases and limitations in reporting
Sources diverge on emphasis: general nutrition pieces highlight bananas as the commonly recognized source and quantify a medium banana’s potassium [1] [3], while lists of “foods that beat bananas” stress that bananas are not the top ten potassium foods and may underdeliver relative to some vegetables and legumes [4] [6]. Databases differ slightly in milligram values by serving size, and a fair limitation across the reporting is that “per serving” comparisons depend on how foods are prepared and portioned — raw versus cooked, mashed versus whole — so exact rankings shift by context [11] [4].
Bananas are therefore a good, convenient source of potassium and a useful part of a potassium‑rich diet, but they are not uniquely superior; relying on a broader range of vegetables, legumes, fruits and some animal foods will more efficiently meet recommended potassium intakes [4] [7] [5].