SETTING: There is sparse epidemiologic information regarding the role of dietary factors in the development of idiopathic pulmonary fibrosis (IPF).
OBJECTIVE: To examine the relationship between specific types of fatty acids and selected foods high in fat and IPF in Japan.
DESIGN: Included were 104 cases aged >= 40 years who had been diagnosed in the last 2 years in accordance with the most recent criteria. Controls aged >= 40 years consisted of 56 hospitalised patients diagnosed as having acute bacterial pneumonia and four out-patients with common cold.
RESULTS: Intake of saturated fatty acids, mono-unsaturated fatty acids, n-6 polyunsaturated fatty acids and meat was independently associated with an increased risk of IPF. Specifically, the multivariate OR for comparison of the highest with the lowest quartile of intake of saturated fatty acids was 6.26 (95%CI 1.79-24.96, P for trend = 0.01) and for meat it was 7.19 (95%CI 2.15-27.07, P for trend = 0.02). Intake of cholesterol, n-3 polyunsaturated fatty acids, fish, eggs and dairy products was not related to the risk.
CONCLUSION: These findings suggest that consumption of saturated fatty acids and meat may increase the risk of IPF.