More reasons to eat more fruits and veggies
Elsevier
Doctors recommend making fruits and vegetables a foundational part of the treatment of patients with hypertension. Diets high in fruits and vegetables are found to lower blood pressure, reduce cardiovascular risk, and improve kidney health due to their base-producing effects.
A new study in The American Journal of
Medicine, published by Elsevier, details the findings from a five-year
interventional randomized control trial.
Despite
ongoing efforts to improve hypertension treatment and reduce its adverse
outcomes with pharmacological strategies, hypertension-related chronic kidney
disease and its cardiovascular mortality are increasing. Heart disease is the
number one reason that patients with chronic kidney disease die.
The Dietary Approaches to Stop Hypertension (DASH) diet that is rich in fruits and vegetables reduces blood pressure and is the recommended first-line treatment for primary hypertension. Nevertheless, this diet is under-prescribed, and when prescribed is under-implemented despite supportive epidemiological data.
The
DASH diet and others generally high in fruits and vegetables are associated
with lower blood pressure, lower risk for and progression of chronic kidney
disease, lower cardiovascular disease risk indicators, and lower cardiovascular
disease mortality.
Lead investigator of the study Donald E. Wesson, MD, MBA, Department of Internal Medicine, Dell Medical School -- The University of Texas at Austin, says, "As a nephrologist (kidney doctor), my acid-base laboratory studies ways by which the kidney removes acid from the blood and puts it into the urine. 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 (long term) exposed to an acid-producing diet. Our patient studies showed similar findings: that is, 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. We hypothesized that one way that fruits and vegetables are both kidney- and heart-healthy is that they reduce the amount of acid in the diet and therefore the amount of acid that kidneys have to remove from the body."
To
test this hypothesis, a study was designed in which participants with
hypertension, but not diabetes, and very high levels of urine albumin excretion
(macroalbuminuria) were selected. Patients with macroalbuminuria have chronic
kidney disease, a high risk for the worsening of their kidney disease with
time, and a high risk to subsequently develop cardiovascular diseases. In a
randomized control trial over a five-year period, investigators divided the
cohort of 153 patients with hypertension into three groups:
Study
participants adding 2-4 cups of base-producing fruits and vegetables in
addition to their usual daily food intake
Study
participants prescribed NaHCO3 (acid-reducing sodium
bicarbonate, which is common baking soda) tablets in two daily doses of 4-5 650
mg tablets
Study
participants receiving standard medical care from primary care clinicians
The
results of the study show that both fruits and vegetables and NaHCO3 improved
kidney health, but only fruits and vegetables, and not NaHCO3,
reduced blood pressure and improved indices of cardiovascular disease risk.
Co-investigator
Maninder Kahlon, PhD, Department of Population Health, Dell Medical School --
The University of Texas at Austin, explains, "Importantly, fruits and
vegetables achieved the latter two benefits with lower doses of medication used
to lower blood pressure and reduce cardiovascular disease risk. 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.
This supports our recommendation that fruits and vegetables should be
'foundational' treatment for patients with hypertension, because we accomplish
all three goals (kidney health, lower blood pressure, and reduced
cardiovascular disease risk) with fruits and vegetables, and we can do so with
lower medication doses.
The
research team emphasizes "foundational" because many clinicians begin
hypertension treatment with drugs and then add diet strategies if blood
pressure is not properly controlled. The findings from its studies support the
opposite: treatment should begin with fruits and vegetables and then add drugs
as needed.
Dr.
Wesson concludes, "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. 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 researchers also advise patients with hypertension to ask their clinician to measure a urine albumin-to-creatinine ratio (UACR) to determine if they have underlying kidney disease and an increased risk for subsequent cardiovascular disease.