The contributing editor, Linda Milo Ohr of Food Technology magazine has written about some food that have a beneficial effect on lowering blood pressure.
Results from a study of 32 pre-hypertensive adult subjects showed that a patented grape seed extract may help to lower both systolic and diastolic blood pressure after just eight weeks (Polyphenolics, 2013a).
A study (Katz et al, 2012) showed that 56 g of walnuts a day cut systolic blood pressure and did not lead to weight gain.
During a 12-week study, researches gave 46 pre-hypertensive subjects raisins or other snacks equal in calorie value three times a day. At weeks four, eight and 12 weeks, subjects eating the raisins showed a significantly reduced systolic blood pressure (Bays et al, 2012).