Plant-based diet can prevent, reverse major form of heart disease, study finds

Chest pain can be frightening, especially when tests show your major heart vessels look clear. Many women in particular live with this confusing problem, only to later learn that the trouble lies in the small vessels that feed the heart.

This condition, called coronary microvascular dysfunction, raises the risk of heart attack and heart failure. It also often leaves patients cycling through drugs that bring limited relief. A new study from Georgia State University offers a hopeful twist by showing that everyday food choices may help protect these tiny vessels and even restore their function.

Coronary microvascular dysfunction happens when the small arteries controlling blood flow to the heart stop responding as they should. These vessels stiffen, send less oxygen to heart tissue and trigger persistent chest pain.

Women tend to experience the disease more often than men and are hospitalized at higher rates after diagnosis. High blood pressure is one of its strongest drivers, but even after treating hypertension, many people still struggle with the condition. That gap in care makes new approaches urgent.

Researchers at Georgia State set out to ask whether a diet filled with whole plant foods could protect the heart’s smallest vessels. They used female spontaneously hypertensive rats, an established model that mimics many features of human disease.

The team compared a refined diet with no plant foods to a plant-based diet made up of fruits, vegetables, legumes and nuts. Both diets contained the same nutrients so the only real difference came from the plant foods themselves and their natural antioxidants.

One group of rats ate the plant-based diet from early life to see if microvascular problems could be prevented. Another group switched to the diet later to test whether established disease could be treated. A third group received antibiotics to clear gut microbes to determine whether the gut played a key role in the diet’s effects.

After months on their assigned diets, the animals underwent coronary flow reserve testing, a clinical measure used to judge how well blood flow rises when heart tissue needs more oxygen. They also received cardiac MRI scans in Georgia State’s Advanced Translational Imaging Facility so researchers could watch how heart muscle perfusion changed.

The results stood out. Rats eating plant foods kept normal blood flow when normally this strain shows strong decline. Even more striking, older animals with established dysfunction regained normal flow after just twelve weeks on the plant-rich diet. These improvements appeared even though the rats still had high blood pressure. That suggests the diet acted directly on the small vessels rather than through lowering pressure.

Rami S. Najjar, the study’s corresponding author and a postdoctoral fellow at Emory University School of Medicine, said the diet “both prevented the development of CMD and reversed established CMD in hypertensive rats, which translates well to the clinical setting.” He also noted that benefits continued “despite the persistence of hypertension,” which shows the diet acted on the vessel lining itself. When those cells malfunction, vessels constrict and restrict blood flow. The diet restored their ability to relax so blood could move through the heart normally again.

The team traced several biological shifts in the animals eating whole plant foods. Their endothelial cells produced more nitric oxide, a chemical critical for vessel relaxation. Levels of eNOS, the enzyme that generates nitric oxide, rose and showed stronger activation. Vascular smooth muscle cells also regained normal relaxation pathways, supported by restored phosphorylation of proteins that help vessels open.

The researchers found a steep drop in oxidative stress markers. Protective enzymes such as superoxide dismutase and catalase increased, while signs of oxidative damage fell. Nuclear NRF2, a regulator of antioxidant defenses, rose as well. Inflammatory signals that often drive vessel injury went down, including NF kappa B, JNK and c Jun. Heart tissue analysis showed early scarring in the left ventricle improved, suggesting the heart can remodel when stress on the vessels lifts.

Gut microbes shifted too, with plant-associated species becoming more common. Still, when the team wiped out gut bacteria with antibiotics, the diet’s benefits remained. That finding hints that the protective effects stemmed from the plant foods themselves rather than from changes in the microbiome.

This is one of the first studies to show that diet alone can treat microvascular dysfunction in an animal model. The findings support the idea that nutrient rich foods may help reduce chest pain and long term risk in people with the condition.

If confirmed in people, this work could offer a simple and accessible way to protect the heart’s smallest vessels. Patients living with chest pain that has resisted standard treatments may find added relief through whole plant foods.

These results could guide new nutrition based therapies, lighten medication loads and inspire further research into how everyday eating patterns shape cardiovascular health.

This knowledge may also encourage prevention efforts by showing that the smallest vessels of the heart can recover before serious events occur.

Because current treatments fall short for many, the researchers say these results justify a clinical trial in patients.

Research findings are available online in the Journal of the American Heart Association.

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