Pomegranate Compound Urolithin A Boosts Heart Function by 80% in Heart Failure Models

Heart failure with preserved ejection fraction is one of cardiology's most frustrating challenges. The heart still pumps blood adequately, but stiffened muscle prevents proper filling between beats, causing breathlessness, fatigue, and reduced exercise capacity. It accounts for roughly half of all heart failure cases and is closely linked to aging, obesity, high blood pressure, and diabetes — yet treatment options remain thin.

Researchers at King's College London now report that urolithin A, a compound produced in the gut after eating pomegranates, walnuts, and certain berries, may offer a new therapeutic angle. The study is the first to show that urolithin A activates PKGlα, a protein critical to heart muscle relaxation and vascular function, by targeting a specific amino acid within it. This triggers a cardiovascular-protective signaling pathway.

In animal models of the condition, urolithin A improved key measures of heart function by up to 80% compared with untreated controls. The compound also reduced fibrosis — the harmful scarring that stiffens heart tissue — and limited abnormal enlargement of heart muscle cells, helping them maintain more normal architecture and function.

The team then tested urolithin A in engineered human heart tissue built from stem cells, a model that closely mimics real cardiac muscle. Urolithin A significantly improved relaxation in this tissue, providing an important bridge toward human applicability and reinforcing the mechanistic findings from animal work.

Caveats are substantial. This remains preclinical research; no human clinical trials have been reported yet. Dietary intake of pomegranates produces highly variable urolithin A levels depending on individual gut microbiome composition. The 80% improvement figure comes from animal models, and translation to humans will require rigorous trials. Nonetheless, the dual action — improving relaxation while reducing scarring — makes urolithin A a compelling candidate for a condition that desperately needs new therapies.