Berry Byproduct Supercharges Stiff Hearts

Assorted fruits, vegetables, and salmon slices on plates — Photo: marilyn barbone / Shutterstock

A compound your gut makes from eating pomegranates just boosted failing hearts by up to 80 percent in a new lab study.

Story Snapshot

King’s College London scientists found urolithin A, made from pomegranates, walnuts and berries, improved heart function in preclinical models.
Heart function measures improved by up to 80 percent compared to untreated models.
The study targeted heart failure with preserved ejection fraction, a hard-to-treat condition affecting nearly half of heart failure patients.
The research, funded by the British Heart Foundation, appeared in the journal Science Advances.

What The King’s College London Team Discovered

Scientists at King’s College London found that urolithin A improves the heart’s ability to relax, cuts down scarring, and stops harmful enlargement of the heart muscle. Urolithin A isn’t something you eat directly. Your gut bacteria make it after you eat pomegranates, walnuts, or certain berries. The compound then travels through your body and reaches heart tissue.

In preclinical tests, urolithin A improved measures of heart function by up to 80 percent compared with models that received no treatment. That number comes from lab models, not human patients yet, but it marks one of the strongest results seen for this compound in cardiac research so far.

The Science Behind The Heart Repair

Researchers identified urolithin A as a direct activator of a specific cardiac relaxation pathway. The compound targets a protein site called PKGIα, helping the heart muscle relax properly between beats. This matters because many heart failure patients struggle with stiff hearts that can’t relax and fill with blood the way they should.

The study was published in Science Advances and funded by the British Heart Foundation, giving it institutional backing beyond a single lab’s claims. A team from King’s College London tested urolithin A in animal models and observed measurable improvements across several markers of heart health, including reduced scarring and better pumping function.

Why Heart Failure With Preserved Ejection Fraction Matters

Researchers focused on heart failure with preserved ejection fraction, known as HFpEF, a condition affecting nearly half of all heart failure patients. Unlike other forms of heart failure, HFpEF has long resisted effective treatment. Doctors know the heart looks like it’s pumping fine on paper, yet patients still feel breathless, tired, and swollen. Few drugs have worked well against it.

That resistance to treatment is exactly why this finding draws attention. A natural, food-derived compound activating a specific relaxation pathway offers a new angle doctors haven’t had much success with before. Millions of Americans live with this exact type of heart failure, often with limited options beyond managing symptoms rather than fixing the underlying problem.

Pomegranate-derived compound Urolithin A boosted heart function by up to 80% in models of tough heart failure, easing stiffness, scarring, and enlargement—also improved relaxation in engineered human heart tissue. Could guide future therapies. #HeartHeal… https://t.co/LBQpSKWzpw

— Devin Womack (@devinwo) September 28, 2026

What Lab Results Do And Don’t Prove Yet

Preclinical models help scientists understand mechanisms, but they don’t always predict how a compound behaves in people. One earlier human trial testing urolithin A supplementation in heart failure patients with reduced ejection fraction did not find evidence of improved heart measures. That trial looked at a different type of heart failure using a different dosing approach.

The gap between promising animal data and confirmed human benefit is common in cardiovascular research. Rodent models don’t perfectly copy human heart failure biology, and reviewers have long noted there’s no ideal preclinical model for this condition. That doesn’t erase what King’s College London found. It simply means the next step is testing in actual patients.

What This Means For Patients Watching Their Diet

Nobody should expect a bowl of pomegranate seeds to reverse heart failure overnight. Urolithin A production depends heavily on individual gut bacteria, and not everyone converts pomegranate compounds the same way. Still, the discovery gives researchers a specific molecular target to pursue, and it validates decades of folk wisdom about pomegranates supporting heart health with hard laboratory data behind it now.

Scientists will likely push toward human trials next, testing whether the mechanism seen in lab models translates into real relief for HFpEF patients. Given how few treatments exist for this specific condition, a food-derived compound with a clear biological target is worth watching closely as research moves forward in the coming months and years.