Data from a small study with 10 healthy male subjects aged between 18 and 40 indicated that two cups of cranberry juice per day could improve flow-mediated vasodilation (FMD, - a measure of blood flow and vascular health). The results were presented at the Cranberry Health Research Conference preceding the annual Berry Health Benefits Symposium 2015 in Madison, WI.
“Our results lay the groundwork to better understand the array of potential vascular and cardiovascular health benefits of cranberry polyphenols,” said principal investigator, Ana Rodriguez-Mateos, PhD, from the University Duesseldorf, Germany. “Significant improvements in vascular function from drinking two cups of cranberry juice suggest an important role for cranberries in a heart-healthy diet.”
Cranberry and heart health
While the majority of the science supporting the health benefits of cranberries is for urinary tract health, a growing body of data supports the cardiovascular potential of the berries.
For example, a 2013 study by scientists at the Mayo Clinic and College of Medicine found that two glasses of cranberry juice a day may protect against the development of hardening of the arteries. Writing in the European Journal of Nutrition (Vol. 52, pp 289-296), the Mayo Clinic researchers reported that no effect was observed on the function of the cells lining the arteries (endothelial cells), but cranberry juice may reduce the number of endothelial cells that produce a compound called osteocalcin, which has been linked to hardening of the arteries.
Dr Rodriguez-Mateos and her co-workers prepared cranberry concentrate with water to concentrations ranging from 0 to 117%. The amount of cranberry-polyphenols increased with the concentration.
“Cranberry juice is a rich source of phytonutrients, including proanthocyanidins, anthocyanins and phenolic acids,” explained Dr Rodriguez-Mateos. “Due to this robust profile of polyphenols, our team sought to evaluate the immediate vascular impact of drinking one, 450 ml (or 16 ounces) glass of cranberry juice with a different range of concentrations of cranberry-polyphenols.”
Across the board, all of the cranberry juices benefited FMD – including 25% cranberry juice, equivalent to the commonly consumed cranberry juice cocktail (25-27%), said the researchers. The highest concentration of cranberry-polyphenol juice also showed improvements in systolic blood pressure.
Dr Rodriguez-Mateos told NutraIngredients-USA: “The magnitudes of the FMD increases were around 1 to 2.5% depending on the dose and the timepoint assessed. A decrease in 10 mmHg systolic blood pressure was seen only at the highest dose tested 6 hours post-consumption when compared with baseline levels, not when compared with placebo and decreases of around 10-15% in Augmentation Index were seen in some but not all the cranberry juices in comparison with baseline but not with placebo.”
There are plans to repeat this study with a larger study population, she added, and the data from the current study will be submitted for publication in a peer-review journal by the end of this year.
Source: Cranberry Health Research Conference
October 12, 2015
“Intake and time-dependent effects of cranberry (poly)phenol consumption in vascular function in healthy individuals”
Author: A. Rodriguez-Mateos