Healthy Heart Diet: Potassium in Avocado Toast and Bananas May Prevent Disease

A new study might just validate your avocado toast addiction. Potassium, contained in avocados and also bananas, could help prevent and treat heart disease.

Arteries can stiffen as we age, and that rigidness is a major risk factor for cardiovascular disease. As we become less resilient, so do our arteries. Heart disease kills an estimated one in four Americans each year.

Researchers at the University of Alabama at Birmingham wanted to see if potassium, a mineral common in our diets, might help keep arteries flexible. The team used mice engineered to be susceptible to heart disease when consuming a high-fat diet, according to a release. The animals were given minimal, average or large amounts of potassium.

Heart scans showed that mice given the least amount of potassium had harder arteries and stiffer aortas compared to those given more potassium. Under the microscope, the arteries from the high-potassium mice were less constricted than those of the other animals. The results, published in the Journal of Clinical Investigation, show a causative link—in mice—between potassium and healthy arteries, the researchers say.

Related: Want a Healthy Heart? Eat Chocolate, New Study Says

Because the study was conducted in animals, it's impossible to say whether the findings are relevant to humans. But study author Yabing Chen, a molecular and cellular pathologist, believes they are meaningful. Previous research has not been able to show direct evidence that potassium could improve heart health, though it hinted of a relationship. This study marks a significant step forward in confirming the potential link. Chen plans to do a follow-up study using images of human hearts to see if potassium can prevent or treat artery stiffness.

While arteries were once thought of as just a transportation system for our blood, researchers now know they are important for overall health, writes epidemiologist Donna Arnett, dean of the University of Kentucky College of Public Health. Stiff arteries are at the heart of many cardiac problems, since the organ doesn't receive the nutrients needed, says the Mayo Clinic.

Of course, there is such a thing as having too much potassium. Excess amounts, a condition known as hyperkalemia, can be particularly dangerous for people with heart conditions and those taking certain medications for hypertension or other conditions. The U.S. Food and Drug Administration recommends we consume about 4,700 milligrams of potassium per day. An avocado contains about 1,000 milligrams, so even an excessive avocado toast habit should be safe.

Chen hopes her research will lead lead to longer, healthier lives for millions of people. "Vascular health is critical to our health and aging system," she says. "A man is as old as his artery."

Chen reports she and her team have already started taking supplements.