Pomegranate Compound Could Help Protect Against Heart Disease

A compound made by gut bacteria from pomegranate nutrients might protect arteries. It does this by reducing plaque, easing inflammation, and making plaques less likely to break open. This is according to researchers at Cardiff University.

Scientists found that a molecule called urolithin A is key to these effects. This molecule forms when gut microbes break down pomegranate polyphenols. It shows strong benefits for the heart and blood vessels in early studies on atherosclerosis. Atherosclerosis is the condition that causes most heart attacks and strokes.

Pomegranates have a lot of punicalagin, a polyphenol linked to heart health. But the body doesn't absorb much of it directly. Instead, gut bacteria change it into smaller molecules called urolithins. These can then travel in the blood and affect tissues.

Professor Dipak Ramji, who led the study, said that the real benefits come from what gut bacteria make from pomegranate compounds, not from the fruit itself.

How Urolithin A Protects Cells

Researchers tested punicalagin, ellagic acid (an in-between form), and several urolithins. They used human immune and blood vessel cells grown in a lab. Urolithin A was the most effective. It reduced stress on cells, lowered inflammation, limited immune cell movement, and decreased how much cholesterol macrophages took in. These steps are crucial for plaque forming and growing in arteries.

The team then tested urolithin A in mice that were missing a certain gene and ate a high-fat diet. This setup is often used to study atherosclerosis in humans. After twelve weeks, the treated mice had smaller plaques with fewer inflammatory cells.

The plaques in these mice also had more smooth muscle cells and collagen. These are linked to stronger, more stable plaques that are less likely to break. When plaques break, it's a main cause of heart attacks and strokes.

Professor Ramji noted that these benefits happened without lowering cholesterol levels in the blood. This suggests urolithin A works by calming inflammation and making plaques stable, not by changing fat levels.

Wider Effects on the Body

The benefits went beyond the arteries. Mice given urolithin A had fewer inflammatory cells in their blood. These cells are known to make atherosclerosis worse. At the same time, helpful short-chain fatty acids increased in their blood and waste. This points to good changes in gut bacteria activity.

More tests showed that urolithin A affected many genes involved in inflammation, stress, and how the body uses energy. Harmful processes linked to atherosclerosis were reduced. Protective processes that fight damage and help metabolism became more active.

Professor Ramji explained that these results help show why diets rich in fruits like pomegranates are good for the heart. But he also noted that not everyone's gut bacteria make urolithin A well, so results can differ.

More studies in humans are needed to confirm these findings. If similar effects are seen, urolithin A could help with current heart disease treatments. It could do this by targeting inflammation and making plaques more stable.

Professor Ramji believes this study opens the door for using urolithin A and strategies based on gut bacteria to prevent heart disease.

Deep Dive & References

Anti-Atherogenic Actions of Pomegranate Polyphenol Punicalagin and Its Metabolites: In Vitro Effects on Vascular Cells and In Vivo Atheroprotection by Urolithin A via Anti-Inflammatory and Plaque-Stabilising Mechanisms - Antioxidants, 2026