A compound produced by the body after eating certain fruits and nuts has caught researchers’ attention after experiments revealed improvements of up to 80% in measures of heart function. The finding could open a new avenue for treating a challenging form of heart failure, although the results come with an important limitation.
Researchers at King’s College London investigated urolithin A, a metabolite that gut bacteria can produce after processing compounds found in foods such as pomegranates, walnuts and some berries. Their findings suggest that it could help the heart relax more effectively between beats, but scientists still need to determine whether the benefits translate to people living with heart failure.
The 80% Heart Function Improvement Has an Important Catch
The study, published in Science Advances, examined the effects of urolithin A on experimental models of heart failure with preserved ejection fraction, known as HFpEF. Researchers found that treated animal models showed improvements in certain measures of heart function of up to 80% compared with untreated models, alongside reductions in heart scarring and abnormal enlargement of heart muscle cells.
The results are attracting attention because HFpEF remains a difficult condition to manage. Unlike some forms of heart failure, where the heart struggles to pump blood effectively, HFpEF involves a heart muscle that can still squeeze normally but has difficulty relaxing and filling between contractions. This difference creates a distinct challenge for researchers looking for treatments that address the underlying problem.
Joseph Burgoyne, a senior author of the research at King’s College London, explained the growing burden of the condition in a university release. “Despite its growing burden, treatment options remain limited because the disease is complex and varies considerably between patients,” he said, referring to the challenges faced by people living with HFpEF.
The findings provide a reason to investigate urolithin A further, particularly because researchers also observed improvements in engineered human heart tissue. However, the reported 80% figure comes from experimental models and should not be interpreted as an expected improvement for people who eat pomegranates or take a supplement containing the compound.
Why Heart Failure Can Occur Even When the Heart Pumps Normally
Heart failure is often associated with a weakened heart that cannot pump enough blood to meet the body’s needs. HFpEF presents a different problem because the heart’s pumping action can remain relatively normal while its ability to relax becomes impaired, preventing it from filling efficiently before the next contraction.
How a Stiff Heart Affects Everyday Life
When the heart muscle becomes stiff, pressure can build inside the heart as it attempts to receive blood between beats. This can contribute to fluid accumulation and symptoms such as breathlessness, fatigue and reduced exercise tolerance, making ordinary activities more difficult for affected individuals.
People with HFpEF may struggle with walking longer distances, climbing stairs or completing tasks that previously felt manageable. Symptoms can vary considerably, and breathlessness or fatigue may have several other causes, so an appropriate medical assessment is necessary to establish what is happening.
Why HFpEF Is Difficult to Treat
The condition can develop alongside several health problems, including high blood pressure, obesity, diabetes and ageing-related changes. These factors can interact in different ways, which means two people with the same diagnosis may not have identical underlying problems or respond to treatment in the same manner.
The researchers noted that HFpEF accounts for roughly half of heart failure cases. As populations age and metabolic conditions become more common, understanding the biological mechanisms behind this form of heart failure has become increasingly important for cardiovascular research.
How Urolithin A Appeared to Improve Heart Function
Urolithin A has attracted scientific interest because of its potential effects on cellular health and metabolism. Researchers at King’s College London investigated whether it could influence a protein called PKGIα, which plays a role in blood vessel function and the relaxation of heart muscle.
Their experiments indicated that urolithin A activated this protein and affected a pathway associated with cardiovascular function. The results suggested a possible way to address some of the changes that make the heart stiffer and less efficient in HFpEF, although the precise clinical implications remain uncertain.
Reduced Scarring Inside the Heart
One of the findings involved fibrosis, a process in which scar tissue accumulates within an organ. Excessive fibrosis can interfere with the normal flexibility of heart muscle, potentially making it harder for the heart to relax and fill with blood between contractions.
In the experimental models, urolithin A reduced scarring compared with untreated controls. Researchers also observed less abnormal enlargement of heart muscle cells, suggesting that the compound influenced multiple changes associated with the condition rather than affecting only one measurement of heart function.
Improvements in Heart Muscle Relaxation
The research also found improvements in the heart’s ability to relax between contractions. This is particularly relevant to HFpEF because impaired relaxation is a defining feature of the condition, even when the heart retains its ability to squeeze blood out effectively.
The observed effects suggest that activating the PKGIα pathway could offer researchers a potential therapeutic target. Further studies will need to establish whether this mechanism can be used safely and effectively in patients, as biological changes in experimental models do not always produce meaningful improvements in human health.
What the Human Heart Tissue Experiments Revealed
To investigate whether the findings might have relevance beyond animal models, the researchers tested urolithin A on engineered human heart tissue created using stem cells. This laboratory approach allows scientists to study aspects of human heart muscle function under controlled conditions without conducting an initial treatment trial in patients.
The engineered tissue showed improvements in the speed of contraction and relaxation after exposure to the compound. These observations added support to the possibility that urolithin A influences processes involved in heart muscle function, although laboratory-grown tissue cannot fully reproduce the complexity of a living human cardiovascular system.
The human tissue experiments are an important part of the research because they provide evidence beyond the animal findings alone. Nevertheless, they do not demonstrate that the compound improves symptoms, prevents hospital admissions or extends the lives of people with HFpEF, all of which would require further investigation in clinical studies.
The distinction is especially important when research findings receive attention because of a striking percentage. An improvement in a particular experimental measurement does not automatically translate into an equivalent improvement in a patient’s overall health, and researchers must establish which outcomes matter most in real-world treatment.
Can Eating Pomegranates Help Your Heart Produce Urolithin A?
Urolithin A is produced when certain gut bacteria process compounds found in foods such as pomegranates, walnuts and some berries. This connection has encouraged interest in whether dietary choices could influence the amount of the metabolite produced in the body, but eating these foods does not guarantee a particular level of production.
Individual differences in gut bacteria and metabolism can influence how people process the compounds involved. Consequently, two people eating similar diets may not necessarily produce the same amount of urolithin A, and the current research does not establish how much dietary change would be needed to produce a meaningful cardiovascular effect.
Burgoyne addressed this limitation directly when discussing the findings, stating, “While there isn’t enough evidence to suggest that people should eat pomegranates to treat heart failure, these findings raise the possibility that dietary approaches that enhance urolithin A production may help alleviate this condition.”
His comments leave room for further research into the relationship between diet and cardiovascular health without suggesting that a particular fruit can treat a serious medical condition. For now, pomegranates can be enjoyed as part of a balanced diet, but they should not replace prescribed medication, medical appointments or treatment recommended for heart failure.
What You Can Do Now to Support Your Heart Health
Although the urolithin A findings remain at an early research stage, there are established ways to support cardiovascular health while scientists continue investigating new treatments. A varied diet, regular physical activity and appropriate management of existing health conditions can help address several factors associated with heart disease.
Practical habits worth building into your routine include the following:
- Eat a variety of fruits and vegetables. Pomegranates can be one option alongside berries, citrus fruits, leafy greens and other produce, providing variety within a balanced eating pattern.
- Choose fibre-rich foods regularly. Whole grains, beans, vegetables, fruits and nuts can contribute to a heart-conscious diet while supplying nutrients that support general health.
- Make physical activity manageable. Walking, cycling and other activities suited to your fitness level can support cardiovascular health, with gradual increases helping you build a sustainable routine.
- Monitor your blood pressure. Regular checks can help identify high blood pressure, which is an important cardiovascular risk factor that may otherwise go unnoticed.
- Keep existing health conditions under control. If you have diabetes, high blood pressure or another condition affecting your cardiovascular health, follow the management plan recommended by your healthcare professional.
- Be cautious with supplements. A supplement containing urolithin A should not be assumed to prevent or treat heart failure simply because the compound has produced encouraging experimental results.
These steps cannot guarantee protection against heart failure, and people with established cardiovascular disease may need additional care tailored to their circumstances. Anyone experiencing unexplained breathlessness, persistent fatigue or swelling in the legs should seek medical advice, while sudden severe breathlessness or chest pain requires emergency medical attention.
Why Clinical Trials Are the Next Essential Step
The researchers now need to determine whether urolithin A can deliver meaningful benefits in people living with HFpEF. Clinical trials would need to examine whether the compound improves heart function, reduces symptoms and produces benefits that patients can experience in everyday life, rather than simply changing laboratory measurements.
Researchers would also need to establish an appropriate dose, evaluate potential side effects and determine how the compound might interact with existing treatments. A well-designed randomized controlled trial involving a sufficiently large and diverse group of participants would provide stronger evidence than animal experiments or laboratory-grown tissue alone.
There are additional questions about whether the findings apply equally to different groups of patients. The animal experiments focused on male mice, while HFpEF also affects women, making it important to investigate whether biological differences influence the response to urolithin A.
James Leiper, research director at the British Heart Foundation, emphasised the need for further evidence. “While these findings are promising, the benefits have so far been seen in animals and engineered human tissue, so clinical trials involving people are needed to test if this approach is effective for patients,” he said.
The study was supported by the British Heart Foundation and identifies a potential therapeutic pathway that scientists can investigate further. However, the distance between an encouraging experimental result and an effective medical treatment can be considerable, particularly for a complex condition influenced by several underlying health problems.
The Findings Offer Hope Without Replacing Proven Care
Urolithin A gives researchers a new avenue to explore for a form of heart failure that remains challenging to treat. The improvements observed in animal models, combined with the findings from engineered human heart tissue, provide a scientific basis for further investigation rather than proof of an effective treatment for patients.
For readers, the practical message is straightforward: enjoy pomegranates and other nutritious foods as part of a varied diet, but do not rely on them to treat heart disease. Until clinical trials establish whether urolithin A benefits people with HFpEF, the reported 80% improvement remains an experimental finding, and established medical care continues to be essential.
