Cranberries have well-documented benefits when it comes to improving urinary tract health and a growing body of research around gut health benefits due to their concentration of proanthocyanidins (PACs), which can help decrease bacterial adhesion to maintain healthy gut bacteria and prevent certain gut health issues, according to The Cranberry Institute.
Now research is building around the fruit's cardiovascular health benefits, according to a recent study funded by The Cranberry Institute, the Research Committee of the Medical Faculty of Heinrich-Heine University Dusseldorf, and the Susanne Bunnenberg Heart Foundation grant to Dusseldorf Heart Center.
Study methods and findings
The double-blind, randomized controlled trial of 45 healthy adult men, published in Food & Function, found that men who consumed 9g of whole cranberry powder (equivalent of 100g of fresh cranberries) per day had a significant improvement in heart and blood vessel function vs. study participants who consumed a placebo for one month.
Researchers determined improvements to heart and blood vessel function by monitoring changes to study participants' flow-mediated dilation (FMD), which is considered a sensitive biomarker of cardiovascular disease risk and measures how blood vessels widen when blood flow increases.
An initial pilot study was completed with five healthy young men to confirm the biological activity of the whole cranberry freeze-dried powder. The pilot concluded that cranberry consumption increased FMD and confirmed dosing. The main study was used as the standard study design to then examine 45 healthy men each consuming two packets of whole cranberry freeze-dried powder equivalent to 100g or 1 cup of fresh cranberries, or a placebo, daily for one month.
The study found significant improvements in FMD two hours after first consumption and after one month of daily consumption showing both immediate and chronic benefit. Additionally, researchers identified metabolites in the blood stream after cranberry consumption further indicating the health benefits of cranberries.
"The increases in polyphenols and metabolites in the bloodstream and the related improvements in flow-mediated dilation after cranberry consumption emphasize the important role cranberries may play in cardiovascular disease prevention," said Dr. Ana Rodriguez-Mateos, senior lecturer in nutrition at the department of nutritional sciences at King's College London and senior author of the study.
"Our findings provide solid evidence that cranberries can significantly affect vascular health even in people with low cardiovascular risk," said Dr. Christian Heiss, professor of cardiovascular medicine at the University of Surrey, UK.
Small changes, big health impact
Low consumption of fruits and vegetables is one of the top modifiable risk factors associated with a higher incidence of cardiovascular disease worldwide, commented researchers, adding that growing evidence continues to link the polyphenols from berries with heart health benefits.
"The fact that these improvements in cardiovascular health were seen with an amount of cranberries that can be reasonably consumed daily makes cranberry an important fruit in the prevention of cardiovascular disease for the general public," added Dr. Rodriguez-Mateos.
Source: Food & Function
Published online, doi: 10.1039/D2FO00080F
"Daily consumption of cranberry improves endothelial function in healthy adults: a double blind randomized controlled trial"
Authors: Christian Heiss, et al