Fruits and vegetables' latest superpower? Lowering blood pressure

April 5, 2017, University of Southern California
Credit: CC0 Public Domain

Eating potassium-rich foods like sweet potatoes, avocados, spinach, beans, bananas—and even coffee—could be key to lowering blood pressure, according to Alicia McDonough, PhD, professor of cell and neurobiology at the Keck School of Medicine of the University of Southern California (USC).

"Decreasing is a well-established way to lower blood pressure," McDonough says, "but evidence suggests that increasing dietary potassium may have an equally important effect on hypertension."

Hypertension is a global health issue that affects more than one billion people worldwide. The World Health Organization estimates that hypertension is responsible for at least 51 percent of deaths due to stroke and 45 percent of deaths due to heart disease.

McDonough explored the link between blood pressure and , potassium and the -potassium ratio in a review article published in the April 2017 issue of the American Journal of Physiology - Endocrinology and Metabolism. The review looked at population, interventional and molecular mechanism studies that investigated the effects of dietary sodium and potassium on hypertension.

McDonough's review found several population studies demonstrating that higher dietary potassium (estimated from urinary excretion or dietary recall) was associated with , regardless of sodium intake. Interventional studies with potassium supplementation also suggested that potassium provides a direct benefit.

McDonough reviewed recent studies in rodent models, from her own lab and others, to illustrate the mechanisms for potassium benefit. These studies indicated that the body does a balancing act that uses sodium to maintain close control of in the blood, which is critical to normal heart, nerve and muscle function.

"When dietary potassium is high, kidneys excrete more salt and water, which increases potassium excretion," McDonough says. "Eating a high potassium diet is like taking a diuretic."

Increasing dietary potassium will take a conscious effort, however. McDonough explains that our early ancestors ate primitive diets that were high in fruits, roots, vegetables, beans and grains (all higher in potassium) and very low in sodium. As a result, humans evolved to crave sodium—but not potassium. Modern diets, however, have changed drastically since then: processed food companies add salt to satisfy our cravings, and processed foods are usually low in potassium.

"If you eat a typical Western diet," McDonough says, "your sodium intake is high and your is low. This significantly increases your chances of developing high pressure." When dietary potassium is low, the balancing act uses sodium retention to hold onto the limited potassium, which is like eating a higher sodium diet, she says.

But how much dietary potassium should we consume? A 2004 Institute of Medicine report recommends that adults consume at least 4.7 grams of potassium per day to lower , blunt the effects of dietary sodium and reduce the risks of kidney stones and bone loss, McDonough says. Eating ¾ cup of black beans, for example, will help you achieve almost 50 percent of your daily potassium goal.

McDonough recommends developing public policies to increase intake of dietary potassium from plant-based sources. She also advocates adding potassium content to nutrition labels to help raise consumers' awareness of economical sources of .

Explore further: Higher dietary potassium to sodium ratio can lower CVD risk

More information: Alicia A. McDonough et al, Cardiovascular benefits associated with higher dietary Kvs. lower dietary Na: evidence from population and mechanistic studies, American Journal of Physiology - Endocrinology And Metabolism (2017). DOI: 10.1152/ajpendo.00453.2016

Related Stories

Higher dietary potassium to sodium ratio can lower CVD risk

February 28, 2017
(HealthDay)—Higher dietary potassium seems to be associated with reduced blood pressure, regardless of sodium intake, with the postulated mechanism involving the distal tubule sodium chloride cotransporter (NCC), according ...

Most Americans consume too much sodium, not enough potassium

November 14, 2016
A majority of Americans consume too much sodium and not enough potassium, according to a preliminary study presented at the American Heart Association's Scientific Sessions 2016.

High dietary sodium and potassium may worsen chronic kidney disease

September 17, 2015
High dietary intake of sodium and potassium may speed the progression of kidney disease, according to a study appearing in an upcoming issue of the Journal of the American Society of Nephrology (JASN). The findings could ...

Potassium-rich foods cut stroke, death risks among older women

September 4, 2014
Postmenopausal women who eat foods higher in potassium are less likely to have strokes and die than women who eat less potassium-rich foods, according to new research in the American Heart Association's journal Stroke.

Potassium improved blood pressure in teen girls, salt had no adverse effect

April 27, 2015
Eating 3,000 mg per day of salt or more appears to have no adverse effect on blood pressure in adolescent girls, while those girls who consumed 2,400 mg per day or more of potassium had lower blood pressure at the end of ...

Are current dietary guidelines for sodium and potassium reasonable?

April 7, 2015
To reduce the risk of heart disease and stroke, the World Health Organization recommends we consume no more than 2000 mg of sodium a day—less than a teaspoon of salt.

Recommended for you

Most nations falling short of UN targets to cut premature deaths from chronic diseases

September 21, 2018
People in the UK, US and China have a higher risk of dying early from conditions like cancer, heart disease and stroke than people in Italy, France, South Korea and Australia.

Smart pills dumb down medical care, experts warn

September 21, 2018
Enthusiasm for an emerging digital health tool, the smart pill, is on the rise but researchers at the University of Illinois at Chicago have published a paper in the American Journal of Bioethics that cautions health care ...

China's doctor shortage prompts rush for AI health care

September 20, 2018
Qu Jianguo, 64, had a futuristic medical visit in Shanghai as he put his wrist through an automated pulse-taking machine and received the result within two minutes on a mobile phone—without a doctor present.

Time to ban the sale of energy drinks to children, says senior doctor

September 19, 2018
It's time to bring in laws to ban the sale of caffeinated energy drinks to children and young people in England to tackle the twin epidemics of obesity and mental health problems, argues Professor Russell Viner, President ...

For-profit hospitals correlated with higher readmission rates

September 19, 2018
Patients who receive care in a for-profit hospital are more likely to be readmitted than those who receive care in nonprofit or public hospitals, according to a new study published by University of Illinois at Chicago researchers.

Sugar content of most supermarket yogurts well above recommended threshold

September 18, 2018
A comprehensive survey of ingredients in yogurts highlights high sugar levels in many—particularly organic yogurts and those marketed towards children.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.