title: The Omega-3 Index Is Inversely Associated with Depressive Symptoms among Individuals with Elevated Oxidative Stress Biomarkers.
abstract: Omega-3 (n-3) fatty acid (FA) consumption is thought to improve depressive symptoms. However, current evidence is limited, and whether this association exists among Puerto Ricans, a population burdened by depression, remains uncertain.
  
  
  
  We examined the association between ω-3 FA biomarkers and depressive symptoms as well as the potential influence of oxidative stress.
  
  
  
  Baseline and longitudinal analyses were conducted in the Boston Puerto Rican Health Study (n= 787; participants aged 57 ± 0.52 y, 73% women). Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentration, a measure of oxidative stress, and erythrocyte FA composition were collected at baseline. We calculated the omega-3 index as the sum of eicosapentaenoic and docosahexaenoic acids, expressed as a percentage of total FAs. Baseline and 2-y depressive symptoms were characterized by using the Center for Epidemiological Studies-Depression Scale (CES-D). Statistical analyses included linear and logistic regression.
  
  
  
  Urinary 8-OHdG concentration tended to modify the relation between the erythrocyte omega-3 index and baseline CES-D score (P-interaction = 0.10). In stratified analyses, the omega-3 index was inversely associated with CES-D score (β = -1.74, SE = 0.88;P= 0.02) among those in the top quartile of 8-OHdG concentration but not among those in the lower quartiles. The relation between the omega-3 index and CES-D at 2 y was more clearly modified by 8-OHdG concentration (P-interaction = 0.04), where the omega-3 index was inversely associated with CES-D at 2 y, adjusted for baseline (β = -1.66, SE = 0.66;P= 0.02), only among those with elevated 8-OHdG concentrations. Among individuals not taking antidepressant medications and in the top tertile of urinary 8-OHdG concentration, the omega-3 index was associated with significantly lower odds of a CES-D score ≥16 at baseline (OR: 0.72; 95% CI: 0.53, 0.96) but not at 2 y (OR: 0.83; 95% CI: 0.60, 1.15).
  
  
  
  An inverse association between the omega-3 index and depressive symptoms was observed among participants with elevated oxidative stress biomarkers. These data suggest that oxidative stress status may identify those who might benefit from ω-3 FA consumption to improve depressive symptoms.
authors.affiliation: Clinical Laboratory and Nutritional Sciences and bigornia@bu.edu.
authors.forename: Sherman J
authors.initials: SJ
authors.lastname: Bigornia
authors.affiliation: Department of Medicine, Sanford School of Medicine of the University of South Dakota, Sioux Falls, SD; and.
authors.forename: William S
authors.identifier: 0000-0003-3042-9353
authors.initials: WS
authors.lastname: Harris
authors.affiliation: College of Fine Arts, Humanities, and Social Sciences, University of Massachusetts Lowell, Lowell, MA;
authors.forename: Luis M
authors.initials: LM
authors.lastname: Falcón
authors.affiliation: Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA.
authors.forename: José M
authors.initials: JM
authors.lastname: Ordovás
authors.affiliation: College of Fine Arts, Humanities, and Social Sciences, University of Massachusetts Lowell, Lowell, MA;
authors.forename: Chao-Qiang
authors.initials: CQ
authors.lastname: Lai
authors.affiliation: Clinical Laboratory and Nutritional Sciences and.
authors.forename: Katherine L
authors.identifier: 0000-0001-7640-662X
authors.initials: KL
authors.lastname: Tucker
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D015415:Biomarkers / Q000097:blood*; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D001900:Boston; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003430:Cross-Sectional Studies; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000652:urine; D003863:Depression / Q000097:blood* / Q000188:drug therapy* / Q000208:ethnology; D004912:Erythrocytes / Q000378:metabolism; D015444:Exercise; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007328:Insulin / Q000097:blood; D016014:Linear Models; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D011647:Puerto Rico / Q000208:ethnology; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014280:Triglycerides / Q000097:blood
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D015525:Fatty Acids, Omega-3; D007328:Insulin; D014280:Triglycerides; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine
keywords: APOE; Boston Puerto Rican Health Study; depression; omega-3 fatty acids; oxidative stress