A compound the body makes after eating pomegranates and walnuts may help treat a hard-to-treat form of heart failure, researchers say.

The King's College London study, published in Science Advances, found that urolithin A improved measures of heart function by up to 80 percent in animal models of heart failure with preserved ejection fraction, or HFpEF.

In HFpEF the heart pumps normally but becomes too stiff to relax and refill between beats. It accounts for about half of all heart failure cases, and drugs have struggled to treat it.

The compound activated a protein called PKG1 alpha, which helps heart muscle relax. It also reduced scarring and abnormal enlargement of the heart.

Researchers tested it in engineered human heart tissue grown from stem cells and saw improved relaxation there too.

The findings are still experimental. Clinical trials are needed before urolithin A could become a treatment, and scientists stress that eating pomegranates is not a therapy.

Sources: medicaldialogues.in, welltica.com, medicalxpress.com.