Snacking on Raisins May Nip Hypertension

Raisins linked to lower blood pressure in prehypertensive patients

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Grappling with blood pressure that is slightly elevated? Eating raisins regularly may offer a significant blood pressure benefit, says the first controlled research to study the dried grapes.

Raisins have previously been linked to improved heart health and lower blood pressure, though few scientific studies were available.

"Limit salt intake to help lower elevated blood pressure."

Dr. Harold Bays, medical director and president of Louisville Metabolic and Atherosclerosis Research Center and the study’s lead investigator, noted that it is often stated as fact that raisins drop blood pressure, but little objective evidence was available to back that claim.

He said that investigators found that if there is a choice between snacking on raisins versus another snack such as crackers, raisins will offer more of a blood pressure benefit.

During the randomized controlled clinical trial, researchers followed 46 men and women with pre-hypertension. Participants were randomly assigned to snack on raisins or, prepackaged snacks without raisins or other fruits and vegetables. All of the participants consumed the same number of calories per serving three times a day for 12 weeks. The study was adjusted for variances in nutrition and exercise among participants.

Investigators found that among the group who ate raisins, their blood pressure had dropped an average of 4.8 percent at four weeks, 7.2 percent at eight weeks and 6 percent at 12 weeks. Participants in other groups did not experience a significant change in blood pressure.

The study did not identify why raisins might reduce blood pressure, though investigators noted they contain high amounts of potassium, and contain fiber, polyphenols, phenolic acid, tannins and antioxidants.

Dr. Bays said that potassium is known to lower blood pressure, and also provides antioxidant dietary fiber that may offer a blood vessel benefit by reducing stiffness. He said larger, multi-site trials would be needed to confirm the finding.

This study, funded by the California Raisin Marketing Board through a grant to the Louisville Metabolic and Atherosclerosis Research Center, was presented Sunday at the American College of Cardiology’s annual scientific sessions.

Reviewed by: 
Review Date: 
March 25, 2012
Last Updated:
March 27, 2012