How Bananas Help Lower Blood Pressure

Disclaimer: Results are not guaranteed*** and may vary from person to person***.

Shapiro_010316-(002)Managing blood pressure can be a difficult task and many people often look for ways to make the process easier and less taxing.

Lifestyle remedies, stress management techniques, medications, and more are all employed to try to keep blood pressure in check. Nutrition, of course, also plays a key role, as exemplified by the humble banana. You may have heard that bananas are a great food for lowering blood pressure, but might be skeptical due to how often such claims are bandied about regarding the latest “superfood” fad.

In this case, however, the truth is exactly what it sounds like: bananas are capable of helping lower your blood pressure, but it isn’t as simple as chowing down and letting the fruit get to work.

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Do Bananas Lower Blood Pressure?

Is there a link between bananas and blood pressure? To understand how that might work, we need to begin with the kidneys. Your kidneys help balance the level of fluids in your body and will filter out any excess into the bladder, where it gets expelled as urine. The body’s blood pressure, in turn, is affected by this process. Too much fluid raises blood pressure, while too little reduces it.

The kidneys, like many other parts of the body, carry out their function thanks to a careful balance of chemicals—in this case, sodium and potassium. Potassium helps draw fluid into the kidneys, while sodium helps keep it in the body. When in balance, these two substances maintain a proper equilibrium and don’t negatively impact your health.

However, modern American diets make it very easy to get too much sodium and/or too little potassium, heavily skewing this dynamic. As a result, fluid can’t be disposed of in as timely a manner as it should, and your blood pressure suffers.

Where the bananas come in is with their impressive potassium content. A single banana has around 422 mg of potassium, roughly 10% of the daily recommended value of 4,700 mg for the average adult. This makes a banana an excellent source of the nutrient and capable of giving your diet the boost it needs to get your potassium levels back into balance with your sodium.

How Many Bananas Should You Eat to Lower Blood Pressure?

Strictly speaking, there is no special banana number to aim for. Since potassium’s effectiveness depends on your sodium levels (and vice versa), you would only see a blood pressure decrease if your potassium levels are the larger of the two. Consuming around twice as much potassium as sodium should tilt the balance of your kidneys towards lowering blood pressure.

It is worth keeping in mind, however, that this only applies if your high blood pressure is related to diet and excess sodium. Heart conditions, high stress, swollen arteries, or other health problems that affect blood pressure won’t necessarily be counteracted by boosting the kidney’s filtering ability.

It’s also important not to go overboard—the body likes it when things are in balance and if you let potassium get too out of hand you’ll start to suffer toxicity effects. Due to this, it is very important not to use potassium supplements unless advised by a doctor and rely mainly on dietary sources.

It also matters how much extra sodium you have in your diet. More sodium means you need more potassium, so lowering your sodium intake can go a long way to keeping you from needing a banana bunch every day.

What Studies Say about Bananas and Blood Pressure

In 1997, there was a meta-analysis (a “study of studies”) that looked at 33 clinical trials for potassium intake and supplements. It found that having a potassium intake around 2,300–3,900 mg per day resulted in a slight but noticeable blood pressure decrease. Specifically, people with normal blood pressure saw a 1.8/1.0 mm decrease and those with hypertension saw a 4.4/2.5 mm decrease.

Blood pressure is recorded as a pair of numbers with the one on top/on the left being systolic pressure (the highest force on the arteries, which occurs when the heart pumps) and the one on the bottom/on the right being diastolic pressure (the lowest force on the arteries, which occurs when the heart is at rest and filling with blood). A blood pressure reading that is lower than 120/80 is considered normal, while 140/90 is considered the starting point of hypertension.

Perhaps most tellingly, the analysis noted that the effects were strongest in those who had a higher sodium intake. This further shows that potassium can help counter the effects salt can have on your blood pressure, and that reducing hypertension with bananas might work.

Other Foods that Help Lower Blood Pressure Naturally

While the banana is the poster child for potassium, it is far from the top contender. Here are some other potassium-rich foods that might help you lower blood pressure quickly.

  • Sweet potatoes: A delicious orange side dish. A single, medium-sized sweet potato contains 542 mg of potassium. Since you likely won’t want to eat one raw, consider baking it, mashing it, making it into a soup, or turning it into fries.
  • Avocado: Half an avocado contains 487 mg of potassium, so enjoy your guacamole and go nuts with the salads.
  • White beans: Half a cup of white beans contains 502 mg of potassium. Feel free to turn them into a chili, soup, mix them into a stew, or eat them as a steamed side dish.
  • Yogurt: A standard eight-ounce serving cup of yogurt contains 579 mg of potassium. Spice up the plain taste with some fruit—like a banana—for a major daily dose.
  • Spinach: The clear winner. A single cup of spinach has 839 mg of potassium, easily dwarfing the now-humbled banana. Whether used in quiches, to replace the lettuce in a burger or salad, or as an omelet ingredient, there are a lot of different ways to work this green guy into your diet.

Sources for Today’s Article:
“Understanding Blood Pressure Readings,” American Heart Association web site; http://www.heart.org/HEARTORG/Conditions/HighBloodPressure/AboutHighBloodPressure/Understanding-Blood-Pressure-Readings_UCM_301764_Article.jsp#.VtBcqPkrJ1s, last accessed February 26, 2016.

Birch, J. “5 Foods with More Potassium than a Banana,” Women’s Health web site, May 22, 2014; http://www.womenshealthmag.com/food/foods-high-in-potassium, last accessed February 26, 2016.
“Why Potassium Helps to Lower Blood Pressure.” Blood Pressure UK web site; http://www.bloodpressureuk.org/microsites/salt/Home/Whypotassiumhelps, last accessed February 26, 2016.
“How Much Potassium Is in a Banana,” Chiquita Bananas web site; http://www.chiquitabananas.com/worlds-favorite-fruit/bananas-and-potassium.aspx.
Higdon, Jane, PhD, et al., “Potassium,” OSU Micronutrient Information Center web site; http://lpi.oregonstate.edu/mic/minerals/potassium, last accessed February 26, 2016.


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Dr. Jeffrey Shapiro, MD

About the Author, Browse Jeffrey's Articles

After receiving athletic and academic awards at Yale and Stanford, Jeff has coached those seeking peak wellness, appeared on ABC News 20/20 and served as a consultant for CBS News 60 Minutes and The Late Show with David Letterman. As the author of many research studies and practicing anesthesiology/critical care medicine for more than 20 years, Jeff can be your guide to common sense decision making regarding drugs, supplements and vitamins. With no corporate sponsors and no vitamins or supplements... Read Full Bio »