Eating a diet that is rich in fruits and vegetables over the course of eight weeks appears to lower levels of blood markers for subclinical heart damage and strain, according to a new study. The findings strengthen the recommendations to consume more fruits and vegetables to optimize heart health, the researchers say.

Researchers conducted an observational study among 326 middle-aged adults with no known preexisting heart disease. They were randomly assigned eight weeks of monitored feeding with a control diet typical of American eating patterns; a diet rich in fruits and vegetable but otherwise similar to the control diet; or the DASH diet, which is rich in fruits, vegetables, low-fat dairy, and fiber, with low levels of saturated fat and cholesterol. Studies show that the heart-healthy DASH diet lowers blood pressure and cholesterol.

Using previously collected blood samples from participants, the researchers studied changes in three biomarkers that are used to evaluate cardiovascular disease. These markers include troponin (linked to heart cell damage), natriuretic peptide (cardiac strain), and C-reactive protein (inflammation).

Compared to the control diet, the two diets that were richer in fruits and vegetables significantly reduced biomarkers associated with heart cell damage and heart strain, but neither of the two healthy diets affected  markers of inflammation. The study, partly funded by NHLBI, appeared in the Annals of Internal Medicine.