08-06-2024

How fruits and vegetables improve heart health

Earth.com staff writer

Doctors are increasingly recommending that fruits and vegetables become a central component in the treatment of patients with hypertension.

A diet rich in these foods has been shown to lower blood pressure, reduce the risk of cardiovascular disease, and improve kidney health, largely due to their base-producing effects.

A recent study published in The American Journal of Medicine highlights these benefits, based on findings from a five-year interventional randomized control trial.

Despite advancements in pharmacological treatments for hypertension, related conditions like chronic kidney disease (CKD) and associated cardiovascular mortality are on the rise. Notably, heart disease remains the leading cause of death among patients with chronic kidney disease.

Heart-healthy fruits and vegetables

The Dietary Approaches to Stop Hypertension (DASH) diet, known for its high content of fruits and vegetables, is recommended as the first-line treatment for primary hypertension.

However, this diet is often under-prescribed and, even when recommended, not fully implemented, despite substantial supportive evidence from epidemiological studies.

Diets rich in fruits and vegetables are associated with lower blood pressure, reduced risk and progression of CKD, and lower cardiovascular disease risk and mortality.

Dietary acid and health

The study, led by Dr. Donald E. Wesson of the Department of Internal Medicine at Dell Medical School, University of Texas at Austin, explored the effects of an acid-producing versus a base-producing diet on kidney health.

“As a nephrologist, my acid-base laboratory studies ways by which the kidney removes acid from the blood and puts it into the urine,” said Dr. Wesson.

“Our animal studies showed years ago that mechanisms used by kidneys to remove acid from the blood can cause kidney injury if the animals were chronically exposed to an acid-producing diet.”

Dr. Wesson said that studies in human patients showed similar findings: an acid-producing diet (one high in animal products) was kidney-harmful, and one that is base-producing (one high in fruits and vegetables) is kidney-healthy.

“Other investigators showed that a diet high in fruits and vegetables is heart-healthy.”

Focus of the research

To test the hypothesis that fruits and vegetables reduce dietary acid and thereby benefit kidney and heart health, the study focused on participants with hypertension but without diabetes, who also had high levels of urine albumin excretion (macroalbuminuria).

These participants were at high risk for worsening kidney disease and developing cardiovascular diseases.

The researchers divided 153 participants into three groups: participants adding 2-4 cups of base-producing fruits and vegetables to their daily intake; participants prescribed NaHCO3 (sodium bicarbonate, common baking soda) tablets; and participants receiving standard medical care from primary care clinicians.

Heart benefits of fruits and vegetables

The results of the analysis revealed that both the fruit and vegetable group and the NaHCO3 group experienced improvements in kidney health. However, only the group consuming fruits and vegetables showed a reduction in blood pressure and improvements in cardiovascular disease risk indicators.

“Importantly, fruits and vegetables achieved the latter two benefits with lower doses of medication used to lower blood pressure and reduce cardiovascular disease risk,” noted Maninder Kahlon, a co-investigator from the Department of Population Health at Dell Medical School.

“This means that one can get the kidney health benefits with either fruits and vegetables or NaHCO3, but we get the blood pressure reduction and reduced cardiovascular disease risk with fruits and vegetables, but not with NaHCO3.”

Reducing the need for medication

The findings support the recommendation that fruits and vegetables should be the foundational treatment for patients with hypertension. This approach achieves multiple health benefits – kidney protection, blood pressure reduction, and lower cardiovascular risk – with potentially lower medication doses.

The research team emphasizes that current clinical practice often prioritizes pharmacological treatment, with dietary changes being secondary. However, this study suggests the opposite: dietary interventions should be the first step in managing hypertension, with medications added as needed.

Making fruits and vegetables more accessible

“Dietary interventions for chronic disease management are often not recommended and even less often executed because of the many challenges to get patients to implement them. Nevertheless, they are effective, and in this instance, kidney and cardiovascular protective,” said Dr. Wesson.

“We must increase our efforts to incorporate them into patient management and more broadly, make healthy diets more accessible to populations at increased risk for kidney and cardiovascular disease.”

The study also advises that patients with hypertension should ask their clinicians to measure their urine albumin-to-creatinine ratio (UACR) to assess for underlying kidney disease and potential increased cardiovascular risk.

This proactive measure can help tailor treatment plans to better manage hypertension and its associated risks.