© 2007 American Thoracic Society
On Previous Findings Concerning Preserved Meat Intake and Respiratory DiseaseTo the Editor:In their recent article, Jiang and colleagues reported an interesting association between cured meat consumption and reduced lung function and chronic obstructive pulmonary disease (COPD), as defined by prebronchodilator measures (1). Not noted by the authors, our recent article in the AJRCCM on dietary associations of symptom correlates of COPD supports their findings (2). Using principal components analysis, we examined patterns of dietary intake in relation to the development of persistent cough with phlegm in a population-based cohort of older adults, the Singapore Chinese Health Study. We identified two distinct food patterns, including a "meat–dim sum" pattern characterized by high intake of meat, dim sum foods, and noodle dishes. The highest quartile of the meat–dim sum pattern was associated with a 1.4-fold increase in the risk of cough with phlegm (95% confidence interval [CI], 1.08, 1.89; p for trend = 0.02) and was independent of beneficial effects of intake of fiber from fruit and soy previously identified in this cohort (3). In exploring foods and nutrients highly correlated with the meat–dim sum pattern, we found positive associations with persistent cough with phlegm for two categories of preserved foods: red meat (adjusted odds ratio [OR] for the highest quartile relative to the lowest, 1.40; 95% CI, 1.07, 1.84) and fish/shellfish (OR = 1.38; 95% CI, 1.06, 1.79)—and the correlated sodium intake (OR, 1.36; 95% CI, 1.06, 1.75). A primary motivation for analysis of dietary patterns is the difficulty of teasing out effects of highly correlated foods and nutrients. However, of note with respect to the article by Jiang and coworkers (1), in models with the dietary pattern, sodium, preserved meat, and preserved fish/shellfish, only preserved red meat remained significant (OR, 1.33; 95% CI, 1.01, 1.75; across extreme quartiles). As discussed by Jiang and coworkers (1), preserved meat and fish are high in nitrosamines. In our study, nitrosamine intake was associated with incident cough and phlegm in a single nutrient model (OR, 1.36; 95% CI, 1.07, 1.73; comparing fourth to first quartile of intake), but was not independent of the meat–dim sum dietary pattern. Principal components analysis of dietary intake has been conducted within the NHANES Epidemiological Follow-up Study (4). It would be of interest to analyze dietary patterns in relation to COPD and lung function in the NHANES III to assess whether intake of either cured meat or its correlate, nitrosamine, is more strongly related to risk than the unhealthy dietary pattern characterized by their high consumption.
University of California, Davis, Davis, California
National University of Singapore, Singapore
Fox Chase Cancer Center, Philadelphia, Pennsylvania
University of Minnesota Cancer Center, Minneapolis, Minnesota
National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina FOOTNOTES Conflict of Interest Statement: None of the authors has a financial relationship with a commercial entity that has an interest in the subject of this manuscript. REFERENCES
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
