Whole Cranberry Powder Improves Endothelial Function in Healthy Male Participants

by | Sep 1, 2022 | 2022, Cardiovascular Health, Fruits and Vegetables, Men's Health, Polyphenols

Written by Chrystal Moulton, Staff Writer. One month consumption of cranberry powder versus placebo significantly improved endothelial function by 1.1% (P < 0.001).

cranberriesCranberries have been studied for their wide health benefits mainly attributed to their rich polyphenolic profile1. Not many studies investigate the effects of cranberries on cardiovascular risk biomarkers2,3. Recent studies have focused on the effects of cranberry juice on vascular function4-6, however no study to date has investigated the cardiovascular effects of whole cranberry freeze dried powder in humans7. In a randomized double-blind placebo-controlled study, researchers evaluated the effects of whole cranberry powder on endothelial vascular dilation in healthy male participants7.

Researchers in this trial conducted a pilot study to ensure that the cranberry powder (the test product) had vasodilative effects. Following the pilot trial, researchers conducted a randomized double-blind controlled study to assess the effect of cranberry powder versus placebo powder daily for one month. Primary endpoint with changes in endothelial function measured by flow mediated dilation. Participants consumed to two packets of their assigned powder in 500 mL of water in the morning with breakfast. Measurements were taken at baseline, two hours after consumption, day 1 after consumption, and after one-month daily consumption. Urine collection was made on day 1 and after one-month daily consumption. Fasting blood samples and vascular exams were performed at each timepoint. Participants were asked to stop consuming polyphenol rich foods 48 hours before the beginning of the study. Dietary data was obtained from food frequency questionnaires collected at baseline. Blood pressure and pulse wave analysis were also conducted by qualified researcher at each timepoint. Fasting blood samples were analyzed for LDL and HDL- cholesterol, HBA 1C, glucose, whole blood count, and triglycerides. Urinalysis was done to assess polyphenolic metabolites. Each participant was given 9 grams of their assigned powder to ingest daily (4.5 grams per packet). Those assigned the cranberry powder ingested 525 mg of total polyphenols of which 374 mg were proanthocyaidins daily for one month.

Results from the pilot trial demonstrated that cranberry powder increased flow mediated dilation compared to control (P = 0.018). In the main trial, flow mediated dilation values at one month were significantly increased in the cranberry group compared to baseline values (P < 0.001). This was not true for the control. Comparing day 1 values and one-month values for flow mediated dilation within the cranberry group, research showed an acute increase in flow mediated dilation on both days but this value was significantly lower at one month compared to day one (P < 0.001). No significant differences were observed for HbA1c, glucose, triglycerides, LDL and HDL- cholesterol, total cholesterol, pulse wave analysis, or blood pressure. Following analysis of blood samples, 56 polyphenolic metabolites were quantified. In plasma the most abundant compound after cranberry consumption were benzoic acids, cinnamic acid derivatives, and hippuric acids. Through further analysis researchers identified 5 polyphenolic metabolites that were significant independent predictors of endothelial flow mediated dilation effects. These metabolites are 2,5-dihydroxybenzoic acid, 4-hyrdroxybenzoic acid, 3’-hydroxycinnamic acid, 4’-glucuronide cinnamic acid, and 5-O-caffeoylquinic acid. These five metabolites accounted for 71% of changes in flow mediated dilation effect at 2h post consumption.

In the end, researchers found a significant improvement in flow mediated dilation at 2 hours and one month after daily consumption of cranberry powder compared to control. To the authors knowledge, this was the first study examining vascular function after whole cranberry powder consumption in healthy humans. Additional studies will be needed to verify these findings.

Source: Heiss, Christian, Geoffrey Istas, Rodrigo P. Feliciano, Timon Weber, Brian Wang, Claudia Favari, Pedro Mena, Daniele Del Rio, and Ana Rodriguez-Mateos. “Daily consumption of cranberry improves endothelial function in healthy adults: a double blind randomized controlled trial.” Food & function 13, no. 7 (2022): 3812-3824.

© The Royal Society of Chemistry 2022

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Posted September 1, 2022.

Chrystal Moulton BA, PMP, is a 2008 graduate of the University of Illinois at Chicago. She graduated with a bachelor’s in psychology with a focus on premedical studies and is a licensed project manager. She currently resides in Indianapolis, IN.

Reference:

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  2. Hsia DS, Zhang DJ, Beyl RS, Greenway FL, Khoo C. Effect of daily consumption of cranberry beverage on insulin sensitivity and modification of cardiovascular risk factors in adults with obesity: a pilot, randomised, placebo-controlled study. Br J Nutr. Sep 28 2020;124(6):577-585. doi:10.1017/s0007114520001336
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  7. Heiss C, Istas G, Feliciano RP, et al. Daily consumption of cranberry improves endothelial function in healthy adults: a double blind randomized controlled trial. Food Funct. Apr 4 2022;13(7):3812-3824. doi:10.1039/d2fo00080f