30 October 2017
COPD is the third leading cause of death in the United States. Cigarette smoking accelerates the age-related forced expiratory volume in 1 s (FEV 1) decline, an important determinant for the genesis of COPD. Hispanic smokers have lower COPD prevalence and FEV 1 decline than non-Hispanic whites (NHWs).
A nutritional epidemiological study was conducted in the Lovelace Smokers cohort (LSC; n=1,829) and the Veterans Smokers cohort (n=508) to identify dietary nutrients (n=139) associated with average FEV 1 and its decline and to assess whether nutrient intakes could explain ethnic disparity in FEV 1 decline between Hispanics and NHW smokers.
Nutrients discovered and replicated to be significantly associated with better average FEV 1 included magnesium, folate, niacin, vitamins A and D, eicosenoic fatty acid (20:1n9), eicosapentaenoic acid (20:5n3), docosapentaenoic acid (DPA; 22:5n3), docosahexaenoic acid (22:6n3), and fiber. In addition, greater intakes of eicosenoic fatty acid and DPA were associated with slower FEV 1 decline in the LSC. Among omega 3 polyunsaturated fatty acids, DPA is the most potent nutrient associated with better average FEV 1 and slower FEV 1 decline. Adverse effect of continuous current smoking on FEV 1 decline was completely negated in LSC members with high DPA intake (>20 mg/day). Slower FEV 1 decline in Hispanics compared to NHWs may be due to the greater protection of eicosenoic fatty acid and DPA for FEV 1 decline rather than greater intake of protective nutrients in this ethnic group.
The protective nutrients for the preservation of FEV 1 in ever smokers could lay foundation for designing individualized nutritional intervention targeting “optimal physiological levels” in human to improve lung function in ever smokers. Ethnic disparity in FEV 1 decline may be explained by difference in magnitude of protection of dietary intakes of eicosenoic fatty acid and DPA between Hispanics and NHWs.