A need for bananas? Dietary potassium regulates calcification of arteries

Bananas and avocados, foods rich in potassium, may help protect against pathogenic vascular calcification or hardening of the arteries.
University of Alabama at Birmingham researchers have shown that reduced dietary potassium promotes elevated aortic stiffness in a mouse model, compared with normal-potassium-fed mice. Such arterial stiffness in humans is predictive of heart disease and death from heart disease, and represents an important health problem for the nation as a whole.
The UAB researchers found that increased dietary potassium levels lessened vascular calcification and aortic stiffness. Furthermore, they unravelled the molecular mechanism underlying the effects of low or high dietary potassium.
Such knowledge of how vascular smooth muscle cells in the arteries regulate vascular calcification emphasizes the need to consider dietary intake of potassium in the prevention of vascular complications of atherosclerosis. It also provides new targets for potential therapies to prevent or treat atherosclerotic vascular calcification and arterial stiffness.
A UAB team led by Yabing Chen, Ph.D., UAB professor of pathology and a Research Career Scientist at the Birmingham VA Medical Center, explored this mechanism of vascular disease three ways: living mice fed diets that varied in potassium, mouse artery cross-sections studied in culture medium with varying concentrations of potassium, and mouse vascular smooth muscle cells grown in culture medium.
The animal work was carried out in the atherosclerosis-prone mouse model, the apoliprotein E-deficient mice, a standard model that are prone to cardiovascular disease when fed a high-fat diet. Using low, normal or high levels of dietary potassium (0.3 percent, 0.7 percent and 2.1 percent weight/weight). The UAB team found that the mice fed a low-potassium diet had a significant increase in vascular calcification. In contrast, the mice fed a high-potassium diet had markedly inhibited vascular calcification. Also, the low-potassium mice had increased stiffness of their aortas, and high-potassium mice had decreased stiffness, as indicated by the arterial stiffness indicator called pulse wave velocity, which is measured by echocardiography in live animals.
The different levels of dietary potassium were mirrored by different blood levels of potassium in the three groups of mice.
“The findings have important translational potential,” said Paul Sanders, M.D., professor of nephrology in the UAB Department of Medicine and a co-author, “since they demonstrate the benefit of adequate potassium supplementation on prevention of vascular calcification in atherosclerosis-prone mice, and the adverse effect of low potassium intake.”