New evidence that the DASH diet is good for the heart
The DASH diet, consistently cited as one of the most beneficial diets for a person’s heart health, can make significant improvements in biomarkers associated with subclinical cardiac injury and systemic inflammation, according to new data in the Journal of the American Heart Association.[1]
What is the DASH diet?
DASH is an acronym for Dietary Approaches to Stop Hypertension. The diet was designed to lower an individual’s blood pressure and improve their overall heart health. It focuses on foods heavy in potassium, calcium and magnesium and limits foods high in sodium, saturated fat and added sugars. Fruits, vegetables, whole grains, fish, poultry and nuts are all parts of a well-balanced DASH diet.
What does this new study tell us about the DASH diet?
The study’s authors noted that the DASH diet’s impact on “traditional cardiovascular risk factors” such as blood pressure has already been firmly established. What was less clear, however, was how following this diet may impact key biomarkers such as high‐sensitivity cardiac troponin I (hs-cTnl), N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) and high‐sensitivity C‐reactive protein (hs-CRP).
While hs-cTnl is a biomarker related to cardiac injury, NT-proBNP is a biomarker related to cardiac strain and hs-CRP is a biomarker related to inflammation.
“In this secondary analysis of the DASH‐Sodium trial, we examined the time course of change in biomarkers of cardiac injury, strain and inflammation from consuming the DASH diet in comparison with a typical American diet using measurements obtained at baseline and at approximately weeks four, eight, and 12 after randomization,” wrote corresponding author Stephen P. Juraschek, MD, PhD, a specialist with the division of general medicine at Beth Israel Deaconess Medical Center, and colleagues.
Juraschek et al. focused on data from 208 participants who followed the DASH diet (mean age 47.4 years old, 59.1% female) with another 204 participants (mean age 49.1 years old, 54.4% female) who followed a control diet typical of what the average American eats on a regular basis.
Compared to the control diet, the DASH diet was associated with a reduction in hs-cTnl after just four weeks. However, the difference between the control diet and the DASH diet was not statistically significant until week 12.
“Biomarkers of subclinical myocardial damage, including hs‐cTnI, may provide prognostic information on long‐term cardiovascular disease (CVD) risk, independent of traditional risk factors,” the authors wrote.
A similar pattern was also seen in hs-CRP; the authors highlighted the importance of this finding in their analysis.
“Inflammation is an established risk factor in the pathogenesis of atherosclerotic CVD, and several large observational studies have demonstrated the ability of hs‐CRP to predict CVD events independently of conventional risk factors,” the authors wrote. “Moreover, greater cumulative exposure to elevated hs‐CRP levels is associated with a higher risk of CVD events.”
For NT-proBNP, there was no difference between the two diets. This could be because many study participants were already eating below-average level of sodium prior to the start of the study, the group wrote.
“In conclusion, in comparison with a typical American diet, the DASH diet reduced hs‐cTnI and hs‐CRP progressively over a 12‐week period, suggesting that the DASH diet has cumulative benefits over time on biomarkers of subclinical cardiac injury and inflammation,” the authors concluded. “These findings provide further insight into the positive effects of the DASH diet on subclinical cardiac injury and inflammation and highlight the need for public health policies and interventions that support sustained adherence to a healthy eating pattern for cardiovascular health.”