Raisins are a quick and tasty way to ensure you get your daily recommended allowance of fruit, but research shows they can do much more. These purple and golden dried grapes are also potent antioxidants and rich sources of the mineral boron, which helps protect against osteoporosis. And new research reveals that routine consumption of raisins can significantly lower your blood pressure.

Kentucky researchers found that eating a handful (about 60) raisins three times a day can reduce prehypertension, which is blood pressure that ranges from the normal level of 120/80 to 139/89. Their research, which is believed to be the first study linking raisins and hypertension, was presented in March 2012 at the American College of Cardiology’s scientific session.

A team from Kentucky’s Louisville Metabolic and Atherosclerosis Research Center gave 46 men and women with prehypertension either raisins or packaged snacks like cookies or crackers that had the same number of calories as the raisins. The participants ate the raisins or packaged snacks three times a day for 12 weeks, and their blood pressure was monitored at four, eight and 12 weeks.

At each measurement, the raisin group’s systolic blood pressure (the top number in a blood-pressure reading) dropped between 6 and 10.2 points, while their diastolic blood pressure (the bottom number) fell by 2.4 to 5.2 points. The packaged snack group had no significant reduction in systolic or diastolic blood pressure.

The researchers didn’t identify how the raisins dropped blood pressure, but the speculation is that it’s due to specific nutrients in the fruit.

“Raisins are packed with potassium, which is known to lower blood pressure,” said study leader Harold Bays, MD. “They are also a good source of antioxidant dietary fiber that may favorably alter the biochemistry of blood vessels, causing them to be less stiff, which in turn may reduce blood pressure.”

According to the Centers for Disease Control and Prevention, 28 percent of Americans have prehypertension, which can lead to cardiovascular disease. This study gives hope of a natural way of treatment rather than blood pressure-lowering drugs, which can have serious side effects.