Eating a healthy diet may help patients combat certain chronic lung diseases, according to a recent study HealthDay reported.

An international team of researchers found eating grapefruit, bananas, fish and cheese improved lung function and fewer symptoms among patients with chronic obstructive pulmonary disease (COPD).

COPD is an umbrella term for the progressive lung diseases emphysema and chronic bronchitis. Nearly 15 million people have COPD in the United States, and it is the third leading cause of death nationwide, according to the U.S. Centers for Disease Control and Prevention. 

 "Diet is a potentially modifiable risk factor in the development and progression of many diseases, and there is evidence that diet plays a role in both the development and clinical features of COPD," Corinne Hanson, lead author of the study, said in a statement. "This study aimed to evaluate that association."

For the study, researchers used data from the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) study, which was designed to help determine how COPD progresses and to identify biomarkers associated with the disease. Limited diet records were available for 2,167 ECLIPSE participants who provided dietary intake information at eight time points over a three-year period. Each participant reported the amount of a specific food they had consumed during the previous 24 hours.

Researchers then looked at specific standard lung function measurements for the same group of people, including the six-minute walk test (SMWT), St. George's Respiratory Questionnaire (SGRQ) scores and inflammatory biomarkers.

They found that people who reported recently consuming fish, grapefruit, bananas or cheese had showed improvement in lung function, less emphysema, improved six-minute walk scores, improved SGRQ scores, and a decrease in certain inflammatory markers associated with poor lung function including white blood cells and C-reactive protein.

"This study demonstrates the nearly immediate effects a healthy diet can have on lung function in in a large and well-characterized population of COPD patients," Hanson said. "It also demonstrates the potential need for dietary and nutritional counseling in patients who have COPD."

The findings were presented at the ATS 2014 International Conference.