Blood pressure is higher in Western populations such as the UK, who eat high levels of sodium - salt - found in processed food than societies which consume more natural foods - which are higher in potassium.

However, population studies demonstrate a relation between ‘dietary potassium and lower blood pressure’, regardless of sodium intake.

Eating potassium-foods could be the cure for high blood pressure, scientists claim.

Nat Hawes, author of Nature Cures said: “Potassium and calcium have an important role in regulating high blood pressure.

“Bananas, beans, grapes and raisins, green leafy vegetables, lemons, lentils, nuts, oranges, potatoes with their skins, sunflower seeds, tofu and whole grains are all rich source of potassium.

“Figs are rich in potassium, and fibre which help to stabilise blood pressure.”

A report in the American Journal of Physiology has looked at the effects of sodium and potassium on high blood pressure.

Speaking to Science Daily, Alicia McDonough, professor of cell and neurobiology at the Keck School of Medicine of the University of Southern California said: “Decreasing sodium intakeis a well-established way to lower blood pressure, but evidence suggests that increasing dietary potassium may have an equally important effect on hypertension."

"When dietary potassium is high, kidneys excrete more salt and water, which increases potassium excretion," said Professor McDonough.

"Eating a high potassium diet is like taking a diuretic."

Professor McDonagh said human diets would have consisted of potassium-rich foods - anything they could grow.

Diets would have been low in sodium - which is why humans have evolved to crave it, she said.

The study found the body uses sodium to control potassium levels in the blood.

Professor McDonagh explained: “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.”

The report said: “Basically, the results reinforce the conclusion that consuming a high-K+ diet is similar to taking a NCC-inhibiting thiazide diuretic, without the side effects.”

Thiazide diuretics are a common treatment for high blood pressure.

The report said public policy should develop to encourage people to increase intake of potassium.

NHS Choices said: “Potassium is a mineral that helps control the balance of fluids in the body, and also helps the heart muscle work properly.

“Adults (19-64 years) need 3,500mg of potassium a day. You should be able to get all the potassium you need from your daily diet.

“Taking too much potassium can cause stomach pain, feeling sick and diarrhoea.”