A compound made naturally by the body after eating certain foods may offer a new way to tackle one of the more difficult forms of heart failure. In early experiments, urolithin A, a substance linked to foods including pomegranates, walnuts and some berries, helped stiff heart tissue relax, reduced scarring and limited harmful changes to heart muscle. Researchers at King’s College London found that the compound improved measures of heart function by as much as 80% in animal models. The results, while still far from a treatment for people, point to a previously unexplored biological pathway that could eventually be targeted in cardiovascular disease. Scroll down to read the details.
A heart that can pump, but cannot relax
The study, published in Science Advances and funded by the British Heart Foundation states that the research focuses on heart failure with preserved ejection fraction, or HFpEF. Unlike some other forms of heart failure, the heart’s pumping ability can remain relatively normal in people with HFpEF. The problem comes between beats, when the heart muscle becomes stiff and cannot relax and fill with blood as effectively as it should.The condition accounts for around half of heart failure cases and can cause breathlessness, fatigue, reduced exercise capacity and a significant decline in quality of life. In the UK, it affects nearly half a million people.HFpEF is particularly challenging because it does not have a single cause. Aging, high blood pressure, diabetes, obesity and other metabolic factors can all contribute to the changes that make the heart less flexible.Because the heart continues to contract effectively, many conventional heart failure treatments do not address the underlying problem as directly. Management often involves controlling associated conditions and making lifestyle changes.
How urolithin A works
According to researchers, Urolithin A has attracted scientific interest because of its connection to mitochondrial health and healthy aging. It is not simply obtained directly from food; rather, it is produced when gut microbes break down compounds found in foods such as pomegranates, walnuts and certain berries.The King’s College London researchers identified a new role for the compound in the cardiovascular system. Their experiments showed that urolithin A activates a protein known as PKG1α, which is involved in blood vessel function and the relaxation of heart muscle.By targeting a specific amino acid on the protein, the compound appears to trigger a pathway that helps heart tissue become more responsive and flexible.In animal models, this translated into improvements in measures of heart function of up to 80% compared with untreated models. The researchers also found less fibrosis, or excessive scar tissue, in the heart. Fibrosis can make the muscle increasingly rigid and interfere with its ability to relax. The treatment also limited the enlargement of individual heart muscle cells, another change associated with worsening heart disease.
Encouraging results in human heart tissue
The researchers did not stop with animal experiments. They also tested urolithin A on engineered human heart tissue made using human stem cells. These laboratory-grown tissues are designed to reproduce important aspects of human heart muscle, allowing researchers to study how cardiac cells behave outside the body.In the experiments, urolithin A significantly improved the tissue’s ability to relax. That finding is important because it mirrors the central problem in HFpEF and suggests that the biological mechanism observed in animals may also operate in human cardiac tissue.Urolithin A also has an advantage over many experimental compounds because it has already been investigated in human studies, where it has shown a favourable safety profile.
Why the findings are still early
Despite the promising results, the study does not show that eating pomegranates, walnuts or berries can treat heart failure. The improvements were observed in animal models and engineered human tissue, not in patients with HFpEF. The amount of urolithin A produced after eating these foods can also vary between individuals, partly because its production depends on the composition of the gut microbiome.The researchers therefore see the findings as a potential starting point for developing treatments rather than evidence for a new dietary therapy. Clinical trials will be needed to establish whether urolithin A can safely improve heart relaxation and symptoms in people with HFpEF. Until then, the findings add another piece to the growing picture of how compounds produced from everyday foods may interact with the body’s cardiovascular system.Images Courtesy: istock
About The Author
