A glass of orange juice a day can help to lower blood pressure, studies find.
Orange juice is rich in potassium, which has a powerful effect in lowering blood pressure.
Bananas, green leafy vegetables, avocados and beans are also high in potassium.
A typical Western diet is low in potassium and high in salt, which is bad for blood pressure.
Salt tastes particularly good to us because our ancestors got little in their diet.
The study involved 300 nurses who were split into five groups and given different combinations of supplements to test their effects.
Along with potassium, the researchers also tested the effect of magnesium and calcium, with blood pressure readings taken over a 24-hour period.
The results showed that potassium had the greatest effect on lowering blood pressure.
Professor Frank M. Sacks, the study’s first author, said:
“Surprisingly, when we put the three together, the effect was no greater than potassium alone.
In fact, it was a little lower.”
The results showed that 1,600 milligrams of potassium was enough to lower blood pressure by a modest amount.
However, people in the study did not have high blood pressure.
For people with high blood pressure, the gains would be more significant, said Professor Sacks:
“Previous studies have shown that potassium in people with high blood pressure has a greater effect of lowering blood pressure 4 to 5 mm Hg.
If he or she already has high blood pressure, then they should eat a diet high in potassium or take supplements.”
The study was published in the journal Hypertension (Sacks al., 1998).