Dietary nutrients associated with preservation of lung function in Hispanic and non-Hispanic white smokers from New Mexico

Shuguang Leng,^1,2 Maria A Picchi,¹ Yohannes Tesfaigzi,³ Guodong Wu,¹ W James Gauderman,⁴ Fadi Xu,⁵ Frank D Gilliland,⁴ Steven A Belinsky<sup>1,2,6

1</sup>The Lung Cancer Program, Lovelace Respiratory Research Institute, ²Cancer Control Research Program, University of New Mexico Comprehensive Cancer Center, ³COPD Program, Lovelace Respiratory Research Institute, Albuquerque, NM, ⁴Keck School of Medicine, University of Southern California, Los Angeles, CA, ⁵Pathophysiology Program, Lovelace Respiratory Research Institute, ⁶Cancer Genetics and Epigenetics Program, University of New Mexico Comprehensive Cancer Center, Albuquerque, NM, USA

Background: COPD is the third leading cause of death in the United States. Cigarette smoking accelerates the age-related forced expiratory volume in 1 s (FEV₁) decline, an important determinant for the genesis of COPD. Hispanic smokers have lower COPD prevalence and FEV₁ decline than non-Hispanic whites (NHWs).
Patients and methods: 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 FEV₁ and its decline and to assess whether nutrient intakes could explain ethnic disparity in FEV₁ decline between Hispanics and NHW smokers.
Results: Nutrients discovered and replicated to be significantly associated with better average FEV₁ 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 FEV₁ decline in the LSC. Among omega 3 polyunsaturated fatty acids, DPA is the most potent nutrient associated with better average FEV₁ and slower FEV₁ decline. Adverse effect of continuous current smoking on FEV₁ decline was completely negated in LSC members with high DPA intake (>20 mg/day). Slower FEV₁ decline in Hispanics compared to NHWs may be due to the greater protection of eicosenoic fatty acid and DPA for FEV₁ decline rather than greater intake of protective nutrients in this ethnic group.
Conclusion: The protective nutrients for the preservation of FEV₁ 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 FEV₁ decline may be explained by difference in magnitude of protection of dietary intakes of eicosenoic fatty acid and DPA between Hispanics and NHWs.

Keywords: nutrientomics, spirometry, ethnic disparity