Associations of dairy intake with CT lung density and lung function

Dairy products contain vitamin D and other nutrients that may be beneficial for lung function, but they are also high in fats that may have mixed effects on lung function. However, the overall associations of dairy intake with lung density and lung function have not been studied.

We examined the cross-sectional relationships between dairy intake and computed tomography (CT) lung density and lung function in the Multi-Ethnic Study of Atherosclerosis (MESA). Total, low-fat, and high-fat dairy intakes were quantified from food frequency questionnaire responses of men and women who were ages 45-84 years and free of clinical cardiovascular disease. The MESA-Lung Study assessed CT lung density from cardiac CT imaging and prebronchodilator spirometry among 3965 MESA participants.

Total dairy intake was inversely associated with apical-basilar difference in percent emphysema and positively associated with forced vital capacity (FVC) (the multivariate-adjusted mean difference between the highest and lowest quintiles of total dairy intake was -0.92 [p for trend = 0.04] for apical-basilar difference in percent emphysema and 72.0 mL [p = 0.01] for FVC). Greater low-fat dairy intake was associated with higher alpha (higher alpha values indicate less emphysema) and lower apical-basilar difference in percent emphysema (corresponding differences in alpha and apical-basilar difference in percent emphysema were 0.04 [p = 0.02] and -0.98 [p = 0.01] for low-fat dairy intake, respectively). High-fat dairy intake was not associated with lung density measures. Greater low- or high-fat dairy intake was not associated with higher forced expiratory volume in 1 second (FEV(1)), FVC, and FEV(1)/FVC.

Higher low-fat dairy intake but not high-fat dairy intake was associated with moderately improved CT lung density.