The omega-3 index is inversely associated with depressive symptoms among individuals with elevated oxidative stress biomarkers

Sherman J. Bigornia, William Harris, Luis M. Falcón, José M. Ordovás, Chao Qiang Lai, Katherine L. Tucker

Research output: Contribution to journalArticle

18 Scopus citations


Background: 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. Objectives: We examined the association between ω-3 FA biomarkers and depressive symptoms as well as the potential influence of oxidative stress. Methods: 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. Results: 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 (b = 21.74, 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 = 21.66, SE = 0.66; P = 0.02), only among those with elevated 8-OHdG concentrations. Among individuals not taking antidepressantmedications and in the top tertile of urinary 8-OHdG concentration, the omega-3 index was associatedwith 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). Conclusions: 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 thosewho might benefit from ω-3 FA consumption to improve depressive symptoms.

Original languageEnglish (US)
Pages (from-to)758-766
Number of pages9
JournalJournal of Nutrition
Issue number4
StatePublished - Apr 1 2016
Externally publishedYes



  • APOE
  • Boston Puerto Rican Health Study
  • Depression
  • Omega-3 fatty acids
  • Oxidative stress

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Nutrition and Dietetics

Cite this