Omega-6 fatty acid may lower bipolar risk, finds study

Bipolar disorder is a debilitating mood disorder characterized by recurring episodes of mania and depression. Although its etiology is still unclear, previous studies have shown that bipolar disease is highly heritable.

Given its presence in human milk, arachidonic acid is considered essential for infant brain development and is added to infant formula in many countries. Therefore, it may exert an effect on bipolar disorder risk by affecting neurodevelopmental pathways, which would be consistent with contemporary views of bipolar disorder as a neurodevelopmental disorder. Arachidonic acid can be sourced directly from meat and seafood products or synthesized from dietary linoleic acid (e.g., nuts, seeds, and oils).

“Accumulating evidence indicates a role for metabolites in bipolar disorder and other psychiatric disorders. By identifying metabolites that play causal roles in bipolar disorder, we hoped to be able to highlight potential lifestyle or dietary interventions," said Lead investigator David Stacey.

In the study, by applying Mendelian randomization the researchers identified 33 out of 913 metabolites present in the blood that were associated with bipolar disorder, most of them lipids.

They found that a bipolar disorder risk gene cluster, which encodes enzymes associated with lipid metabolism, mediated the association between bipolar disorder and the levels of arachidonic acid and other metabolites.

"To our knowledge, this is the first study to highlight a potential causal role between arachidonic acid and bipolar disorder. Preclinical studies and randomized controlled trials will be necessary to determine the preventive or therapeutic value of arachidonic acid supplements, perhaps with a particular focus on people with a compromised arachidonic acid synthesizing pathway or with poor natural dietary sources. Our findings also support potential avenues for precision health interventions focused on early life nutrition to ensure that infants and children are receiving enough arachidonic acid and other polyunsaturated fatty acids to support optimal brain development, which may also reduce the risk of bipolar disorder,” concluded Stacey.

Reference: David Stacey, Beben Benyamin, S. Hong Lee, Elina Hyppönen; A Metabolome-Wide Mendelian Randomization Study Identifies Dysregulated Arachidonic Acid Synthesis as a Potential Causal Risk Factor for Bipolar Disorder; Biological Psychiatry; DOI:https://doi.org/10.1016/j.biopsych.2024.02.1005