Small randomized controlled trial is first to put this potassium-rich fruit to the test
If you have slightly higher than normal blood pressure - known as prehypertension - consider eating a handful of raisins. New data suggest that, among individuals with mild increases in blood pressure, the routine consumption of raisins (three times a day) may significantly lower blood pressure, especially when compared to eating other common snacks, according to research presented today at the American College of Cardiology's 61st Annual Scientific Session. The Scientific Session, the premier cardiovascular medical meeting, brings cardiovascular professionals together to further advances in the field.
Even though raisins are popularly cited to lower blood pressure on various websites and are known to have intrinsic properties that could benefit heart and vascular health, researchers believe this is the first controlled study to scientifically support raisins' blood pressure-lowering effects compared to alternative snacks.
"It is often stated as a known fact that raisins lower blood pressure. But we could not find much objective evidence in the medical literature to support such a claim," said Harold Bays, MD, medical director and president of Louisville Metabolic and Atherosclerosis Research Center (L-MARC) and the study's lead investigator. "However, our study suggests if you have a choice between eating raisins or other snacks like crackers and chocolate chip cookies, you may be better off snacking on raisins at least with respect to blood pressure."
In this investigation, Dr. Bays and his team conducted a randomized controlled clinical trial to compare the blood pressure effect of eating raisins versus other snacks in 46 men and women with prehypertension. Participants were randomly assigned to snack on raisins or prepackaged commercial snacks that did not contain raisins, other fruits or vegetables but had the same number of calories per serving three times a day for 12 weeks. The study controlled for individual differences in nutrition and physical activity.
Data analyses found that compared to other snacks, raisins significantly reduced systolic blood pressure at weeks 4, 8, and 12, ranging from -4.8 to -7.2% or -6.0 to -10.2 mmHg (p values <0.05). Within group analysis demonstrated that raisins significantly reduced mean diastolic blood pressure at all study visits, with changes ranging from -2.4 to - 5.2 mmHg (p values < 0.05). Pre-packaged snacks (including crackers and cookies) did not significantly reduce systolic or diastolic blood pressure at any study visit.
"Overall, these findings support what many people intrinsically believe: that natural foods often have greater health benefits than processed foods," Dr. Bays said.
The study did not identify how raisins lower blood pressure. However, raisins are high in potassium, and have fiber, polyphenols, phenolic acid, tannins and antioxidants.