Boosting potassium doesn't have to come with such a high price tag, though.
“If you were to guide people toward the most affordable sources of potassium, you could do it more cheaply,” Monsivais said. Potatoes and beans, for instance, are inexpensive sources of potassium and dietary fiber,
For a mere 95 cents, you could buy five bananas at Trader Joe’s, and they’d provide 450 to 500 milligrams of potassium each.
So why would the participants in Monsivais’ study have to spend so much? King County includes Seattle, one of the most affluent and highly educated cities in the country. When those folks consume potassium, Monsivais says, it tends to come in the form of more expensive fruits and vegetables such as nectarines and dark leafy greens.
Sure, they could eat more economically, but they'd have to know how to do so, Monsivais said. The guidelines may be based on solid scientific evidence, he says, but they won’t do much good if Americans don’t know what foods provide the best nutritional bang for their buck.