Lipids in Health and Disease (Nov 2019)

Omega-3 polyunsaturated fatty acids status and cognitive function in young women

  • Rebecca L. Cook,
  • Helen M. Parker,
  • Cheyne E. Donges,
  • Nicholas J. O’Dwyer,
  • Hoi Lun Cheng,
  • Katharine S. Steinbeck,
  • Eka P. Cox,
  • Janet L. Franklin,
  • Manohar L. Garg,
  • Helen T. O’Connor

DOI
https://doi.org/10.1186/s12944-019-1143-z
Journal volume & issue
Vol. 18, no. 1
pp. 1 – 9

Abstract

Read online

Abstract Background Research indicates that low omega-3 polyunsaturated fatty acid (n-3 PUFA) may be associated with decreased cognitive function. This study examined the association between n-3 PUFA status and cognitive function in young Australian women. Methods This was a secondary outcome analysis of a cross-sectional study that recruited 300 healthy women (18–35 y) of normal weight (NW: BMI 18.5–24.9 kg/m2) or obese weight (OB: BMI ≥30.0 kg/m2). Participants completed a computer-based cognition testing battery (IntegNeuro™) evaluating the domains of impulsivity, attention, information processing, memory and executive function. The Omega-3 Index (O3I) was used to determine n-3 PUFA status (percentage of EPA (20:5n-3) plus DHA (22:6n3) in the red cell membrane) and the participants were divided into O3I tertile groups: T1 6.75%. Potential confounding factors of BMI, inflammatory status (C-reactive Protein), physical activity (total MET-min/wk), alpha1-acid glycoprotein, serum ferritin and hemoglobin, were assessed. Data reported as z-scores (mean ± SD), analyses via ANOVA and ANCOVA. Results Two hundred ninety-nine women (26.9 ± 5.4 y) completed the study (O3I data, n = 288). The ANOVA showed no overall group differences but a significant group × cognition domain interaction (p < 0.01). Post hoc tests showed that participants in the low O3I tertile group scored significantly lower on attention than the middle group (p = 0.01; ES = 0.45 [0.15–0.74]), while the difference with the high group was borderline significant (p = 0.052; ES = 0.38 [0.09–0.68]). After confounder adjustments, the low group had lower attention scores than both the middle (p = 0.01) and high (p = 0.048) groups. These findings were supported by univariate analyses which found significant group differences for the attention domain only (p = 0.004). Conclusions Cognitive function in the attention domain was lower in women with lower O3I, but still within normal range. This reduced but normal level of cognition potentially provides a lower baseline from which cognition would decline with age. Further investigation of individuals with low n-3 PUFA status is warranted.

Keywords