SIB #455- Fish Oils and Mental Health
The Study: Plasma polyunsaturated fatty acids and mental disorders in adolescence and early adulthood: cross-sectional and longitudinal associations in a general population cohort
Overview: High ratios of Omega 6: Omega 3 fatty acids are known to be pro inflammatory and thought to be a relevant factor in disease states characterized by chronic inflammation. Additionally, there is a body of evidence associating low grade inflammation with the presence or risk of mental disorders such as schizophrenia and depression. This study examined associations between blood levels of Omega 3 & Omega 6 fatty acids and mental disorders in a large cohort of young subjects.
Key Points:
Participants from The AVON Longitudinal Study of Parents and Children, a very large, on- going birth cohort study which has been gathering data in the U.K., since the early 90’s were invited to participate in this study.
Participants, aged 17 (5215 Total) and 24 years (4019 Total) , attended clinics where “anthropometric measurements, questionnaires, interviews and blood sample collection were completed.”
The participants were requested to fast for at least 6 hours prior to blood testing.
Blood levels of specific fatty measured included. Total Omega-6, total Omega-3, Omega 6:3 ratio and DHA.
Additionally, patients were evaluated for three mental disorders; psychotic disorder, moderate/severe depressive disorder, and generalized anxiety disorder.
The data was analyzed and adjusted to account for a number of confounding factors including: sex, Body Mass Index, smoking habits, cannabis use, childhood IQ testing and a number of socioeconomic factors.
Author’s Conclusions: There was “little evidence of cross-sectional associations between any PUFA (polyunsaturated fatty acid) measure and mental disorders at age 17. There was, however, a positive association of elevated Omega 6:3 ratio with all three mental disorders (psychotic disorder, moderate/severe depressive disorder, and generalized anxiety disorder) in the age 24 cohort. Interestingly, the association seemed to only relate to the Omega 6:3 ratios and not to the total level of the various fatty acids.
The authors conclude that increasing dietary intake of anti-inflammatory Omega 3 fats (think fish and flax seed oils) while decreasing the pro-inflammatory Omega 6 fats (think grain oils) could potentially reduce risk of mental illness (at least in the age 24 cohort) by reduction of neuroinflammation.
(Italics and bold emphasis ours)
Reviewer's Comments: This study is in keeping with prior works indicating a high Omega 3:6 ratio seems desirable in terms of mental health. While supplementation with fish oils to boost Omega 3s seems reasonably safe and prudent, it remains unclear at this time whether or not supplementation alone can substantially alter the 3:6 ratio without also working to reduce the intake of pro-inflammatory Omega 6 oils.
Reviewer: Mark R. Payne DC
Reference: David Mongan, Colm Healy, Hannah J. Jones, Stan Zammit, Mary Cannon and David R. Cotter. Plasma polyunsaturated fatty acids and mental disorders in adolescence and early adulthood: cross-sectional and longitudinal associations in a general population cohort. Translational Psychiatry (2021) 11:321 https://doi.org/10.1038/s41398-021-01425-4
Link to Full Text: https://www.nature.com/articles/s41398-021-01425-4.pdf