Study Shows Blackcurrant Juice Supports Vascular Health

Richly hued and naturally tangy, blackcurrants pack more than just flavor. They're a concentrated source of vitamin C and polyphenols that give them their deep purple color and potent antioxidant power. Scientists have long suspected that such compounds could help protect the body's delicate vascular system, especially in people who don't consume enough fruits and vegetables. A clinical trial put this idea to the test, examining whether blackcurrant juice could help improve the circulatory system.

The Study

Researchers from the University of Dundee in Tayside, Scotland, conducted a double-blind, placebo-controlled trial to evaluate how blackcurrant juice affects vascular function and oxidative stress. The study enrolled 66 healthy adults who consumed fewer than two portions of fruit and vegetables per day.

Participants were randomly assigned to drink either a placebo or a low- or high-polyphenol blackcurrant juice (250 mL, four times daily) for six weeks. Researchers measured flow-mediated dilation, an indicator of endothelial function, along with plasma vitamin C and markers of oxidative stress.

The Results

After six weeks, those consuming the high-polyphenol blackcurrant juice experienced a significant improvement in endothelial function compared to a slight decline in the placebo group.


Vitamin C levels rose notably, especially in the high-juice group, while oxidative stress markers decreased significantly. Improvements in vascular function correlated with higher plasma vitamin C, suggesting a synergistic effect between vitamin C and polyphenols.

What Does this Mean?

This clinical trial provides strong evidence that regular consumption of blackcurrant juice helps support vascular health, particularly in people with low fruit and vegetable intake. For reference, current recommendations suggest consuming at least five portions of fruits and vegetables per day.¹

These benefits are most likely due to blackcurrants' naturally high content of the antioxidants vitamin C and polyphenols. Adding blackcurrants to a daily diet can be a simple and flavorful way to boost antioxidant intake and promote wellness.

Similar antioxidant and vascular-supporting compounds are also found in foods like blueberries, pomegranates, and dark grapes.