New Review Links Blueberry and Grape Polyphenols to Improved Vascular Function

The researchers reviewed 37 studies, including 20 clinical trials and 17 systematic reviews and meta-analyses.

Overall, the evidence suggests these fruits and their compounds may:

• Improve blood vessel function

• Slightly lower blood pressure

• Reduce inflammation

• Protect LDL ("bad") cholesterol from damage

• Reduce oxidative stress, which can harm blood vessels

One high-quality study found that older men with metabolic syndrome who ate blueberries daily for six months had healthier blood vessels and reduced artery stiffness. Researchers estimated these improvements could potentially lower heart disease risk, although the study did not measure actual heart attacks or strokes.

Some studies also found that grape products improved cholesterol levels and blood vessel health, especially in people with high cholesterol or metabolic problems.

However, the researchers pointed out several important limitations. Many studies were small, lasted only a few weeks or months, and often used grape extracts, powders, supplements, or red wine instead of fresh fruit. This makes it difficult to know whether eating whole grapes or blueberries provides the same benefits.

The researchers conclude that adding grapes and blueberries to a healthy diet may support heart health, but larger, long-term studies are still needed to confirm whether these fruits can actually prevent cardiovascular disease.

REFERENCE: Derbyshire, E. J., Abellán-Alemán, J. A., & Aslam, N. (2026). Polyphenols and Cardiovascular Health: Emerging Relevance for Blueberries, Grapes, and Red-Fleshed Table Grapes. Nutrients, 18(12), 1968. DOI: 10.3390/nu18121968, https://www.mdpi.com/2072-6643/18/12/1968