The study says: “We included 11 randomised, double-blind, placebo-controlled trials involving 387 participants with oral L-arginine intervention ranging from four to 24 grams a day.
“Compared with placebo, L-arginine intervention significantly lowered systolic blood pressure by 5.39 millimetres of mercury (mm/Hg) and diastolic BP by 2.66 mm/Hg.”
Blood pressure is recorded with two numbers; systolic and diastolic pressure.
The higher number that appears on a blood pressure test – systolic pressure – refers to the force at which your heart pumps blood around your body.