High blood pressure happens when the force of a person’s blood pushing against their artery walls is confidently too high. Prehypertension means a person’s blood pressure is slightly above normal. It will likely turn into high blood pressure (hypertension) unless a person makes lifestyle changes. Evidence suggests snacking on raisins can help to avert the risk of a rising reading.
Regular consumption of raisins (three times a day) may significantly lower a person’s 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.
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.
He added: “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 randomised 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 for up to 12 weeks.
Within group analysis demonstrated that raisins significantly reduced mean diastolic blood pressure at all study visits.
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 fibre, polyphenols, phenolic acid, tannins and antioxidants.
“Raisins are packed with potassium, which is known to lower blood pressure,” Dr. Bays said.
He added: “They are also a good source of antioxidant dietary fibre that may favourably alter the biochemistry of blood vessels, causing them to be less stiff, which in turn, may reduce blood pressure.”
Dr. Bays cautioned that this was a single site study; larger trials are needed to confirm the blood pressure-regulating effect of raisins. Nonetheless, he says work in this area is particularly exciting because applying similar scientific methods to natural products, as required for drug development, provides consumers with objective data about which foods may or may not benefit heart health.
According to Blood Pressure UK, the following potassium-rich fruits may also be helpful in controlling blood pressure:
- Tomato juice and puree
- Orange juice
“To make your fruits even more effective, don’t forget to cut down on the amount of salt you are eating,” advised the health site.