Eating Bananas Every Day Has An Unexpected Effect On Your Lungs

It's easy to take your lung health for granted — until you get a cold or flu, that is. The moment you begin to cough or wheeze, you realize just how much you rely on properly functioning lungs to get you through life. Without sufficient lung power, you couldn't make it through a tough workout — or belt out your favorite tune at karaoke night.

One strategy to keep your lungs performing involves eating a diet that's lung-friendly. Plenty of foods contain nutrients that promote lung health, including bananas. (Read about the unexpected effect of drinking cranberry juice daily on your lung cancer risk.)

Two nutrients found in bananas are especially beneficial for your lungs: potassium and magnesium. Every time you eat a medium-sized banana, you get 422 milligrams of potassium and 31.9 milligrams of magnesium. For comparison, the average adult needs 2,400 milligrams to 3,600 milligrams of potassium and 310 milligrams to 420 milligrams of magnesium daily. That means one banana could edge you significantly toward each goal.

But what makes potassium and magnesium so good for your lungs? Potassium may lower your risk of developing lung cancer, which is one of the three most diagnosed cancers annually in the United States (per the National Cancer Institute) and the leading cause of cancer deaths.

A 2021 review in Translational Lung Cancer Research looked at evidence from a trial that explored the possible relationship between potassium and lung cancer. The review found that when women increased their consumption of potassium, their chances of experiencing lung cancer dropped. However, the authors cautioned against exceeding normal intake values of potassium, as excessive potassium levels seemed to lessen the protective effect. With regard to the mechanism by which potassium can help reduce lung cancer risk, the authors cited the potential of potassium to help T-cells, a type of cell found throughout the body. T-cells can keep cancer cells from growing under the right conditions.

Potassium may keep you from getting a condition called chronic obstructive pulmonary disease (COPD) as well. COPD affects the whole respiratory system and is one of the deadliest diseases in the United States. A 2022 review in BMC Emergency Medicine identified a connection between inadequate potassium levels and COPD development. In fact, up to one out of every five COPD subjects whose outcomes were included in the analysis had hypokalemia (low potassium). This is where magnesium enters the mix. Like potassium, magnesium may also protect you against some symptoms related to COPD. (Yet another reason to buy some bananas on your next shopping trip — and make sure you wash your bananas before storing them.) 

In a 2021 study in Aging Clinical and Experimental Research, half the participants (all with COPD) took 300 milligrams of magnesium citrate once a day for six months. Though their lung function didn't improve, their inflammation levels seemed to get better, suggesting that magnesium could potentially facilitate easier breathing. Additionally, since magnesium is known to support muscle function, it might bolster the capabilities of the muscles around the lungs. A 2024 study in Scientific Reports also supported the use of magnesium to lower the likelihood of COPD, echoing the importance of magnesium to boost muscle health and ward off inflammation.