Eating bananas on a daily basis could prevent heart attacks and strokes, a new study has found.
The vital mineral — which spuds, broccoli and sprouts are also rich in — was found to aid blood flow to the heart and brain and reduce the risk of clots.
Other good sources of potassium include parsnips, seeds, fish and poultry.
Its effect on the arteries emerged in US lab tests on mice.
Researchers at the University of Alabama fed some a diet low in the mineral while others got extra.
Those that ate potassium-rich foods ended up with a better blood flow.
Official NHS advice is to consume 3,500mg of potassium a day — and four bananas can contribute half of that amount.
However, eating too much can cause stomach ache, nausea and diarrhoea.
Older people may be more at risk because their kidneys may be less able to remove potassium from the blood.
Dr Mike Knapton, from the British Heart Foundation, said the study in mice showed that not eating enough potassium leads to the hardening of arteries.
He added: “With more research, we might be able to see if the disease forms in humans in a similar way and develop treatments.”
The NHS urges Brits to see GPs before any dramatic changes in diet.