Researchers from the University of Scranton previously suggested that nutrients found in cranberry juice can effectively reduce the risk of heart disease -- in some cases, up to 40 percent -- mostly by increasing levels of HDL, the "good" cholesterol. The juice was also shown to increase blood levels of antioxidant nutrients by up to 121 percent.
Previous research has also shown that cranberry juice helped relax blood vessels clogged with high blood cholesterol and narrowed by atherosclerosis, according to a study by researchers at the University of Wisconsin School of Veterinary Medicine.
Another study in the European Journal of Nutrition indicate that cranberry juice may reduce the number of endothelial cells that produce a compound called osteocalcin, which has been linked to hardening of the arteries.
"It is one of the most important fruit juices you can drink -- with protective qualities that can make an important difference in your health, particularly your heart health," says Joe Vinson, the researcher who presented the findings.
The new double-blind, placebo-controlled, parallel-arm study - performed by USDA researchers 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.
The trial was registered at clinicaltrials.gov as NCT01295684 .
Mae Chan holds degrees in both physiology and nutritional sciences. She is also blogger and and technology enthusiast with a passion for disseminating information about health.