Assessment of dietary fat intake and innate immune activation as risk factors for impaired lung function

Preservation of lung health with aging is an important health issue in the general population, as loss of lung function with aging can lead to the development of obstructive lung disease and is a predictor of all-cause and cardiovascular mortality. Inflammation is increasingly linked to loss of lung function and evidence suggests that consumption of dietary fat exacerbates inflammation. We aimed to determine the association between dietary fat intake and lung function in older people.

Participants from the Hunter community study, a population-based cohort, were recruited during 2004 and 2005. Participants received a clinical assessment, including spirometry, and provided a blood sample. Diets were analyzed using food-frequency questionnaires. Plasma interleukin (IL)-6 and C-reactive protein was measured by Enzyme-Linked immunosorbent assay.

Using backward stepwise linear regression, %energy from dietary fat, age and plasma IL-6 were considered as negative predictors of forced expiratory volume in one second (FEV(1)) in men. Also in men, % energy intake from dietary fat, age, body mass index and IL-6 were negative predictors of %predicted forced vital capacity (FVC). Smoking and age were negative predictors of FEV(1)/FVC. In women, plasma IL-6 and age were negative predictors of %FVC, whereas obesity was positively associated with FEV(1)/FVC.

An increased proportion of fat in the diet is associated with the reduced lung function in older men. Dietary-fat induced innate immune activation and IL-6 release may contribute to this effect. Dietary interventions involving fat restriction should be further investigated as means of preserving lung function with aging.