The double-blind, placebo-controlled, parallel-arm study - performed by USDA researchers in addition to scientists from cranberry juice manufacturer Ocean Spray - examined how consumption of the polyphenol-rich cranberry juice affected cardiometabolic risk factors over an eight week period.
Writing in the Journal of Nutrition, the team revealed that the low-calorie cranberry juice can improve several risk factors of cardiovascular disease (CVD) in adults - including circulating fasting serum triglycerides (TGs), C-reactive protein (CRP), and glucose, insulin resistance, and diastolic blood pressure.
"These findings suggest that polyphenols help to protect our bodies, and may be adept at keeping a large number of ailments at bay," said study co-author Christina Khoo, PhD, director of research sciences at Ocean Spray. "Among the commonly consumed fruits in our diets, cranberries boast some of the highest levels of polyphenols - more than apples, blueberries, grapes or cherries."
The researchers from the United States Department of Agriculture and Ocean Spray provided eight weeks' worth of meals to 56 healthy adult volunteers, with an average 50 years.
One group drank a glass (8 oz) of low-calorie cranberry juice twice daily (16 oz total), while the other group drank a placebo beverage with a similar colour and flavour.
"At the start and end of the experiment, the researchers measured things like blood pressure, blood sugar levels, blood lipids, as well as C-reactive protein, a marker of inflammation," explained Khoo.
"All of these measurements come together to tell a story,” she said. “The worse off these numbers are in an individual, the more likely he or she will face a health condition like diabetes, heart disease or stroke in the future."
The team found that individuals drinking two glasses of the low-calorie cranberry juice each day improved across all the measures.
Such a change that adds up, and could be associated with a 10% lower risk of heart disease and a 15% lower risk of stroke, said the team.
Of note, the reductions in blood pressure alone matched those achieved from top-rated diets like the DASH (Dietary Approaches to Stop Hypertension) diet; an eating pattern established as the gold standard for lowering blood pressure after several successful studies by the National Institutes of Health, said the team.
Source: Journal of Nutrition
Volume 145, Number 6, Pages 1185-1193, doi: 10.3945/jn.114.203190
“Cranberry Juice Consumption Lowers Markers of Cardiometabolic Risk, Including Blood Pressure and Circulating C-Reactive Protein, Triglyceride, and Glucose Concentrations in Adults”
Authors: Janet A Novotny, et al