Omega-6 fatty acids, which are typically found in eggs, poultry, and seafood, may lessen the risk of bipolar illness, according to a world-first study conducted by the University of South Australia.
Using Mendelian randomization, an effective causal inference method, researchers analysed 913 metabolites in 14,296 Europeans and discovered 33 (mainly lipids) correlated with the risk of bipolar disorder.
Mendelian randomization (MR) is an instrumental variable estimation method that utilizes germline genetic variation, typically in the form of single nucleotide polymorphisms (SNPs), as a proxy for a putative exposure. This approach aims to test and estimate the causal effect of exposure on an outcome using observed data.
Bipolar disorder is a severe mood illness defined by recurrent periods of mania and depression. Although the exact cause is unknown, previous research has revealed that bipolar disorder is highly heritable. If a parent develops bipolar, a child has a one in ten likelihood of developing the disorder.
One in every eight individuals worldwide suffers from a mental illness, with around 40 million suffering from bipolar disorders. Nearly 3% of Australians (568,000 over the age of 16) suffer from bipolar disorder.
Dr. David Stacey, the chief researcher, said the new findings pave the way for innovative potential lifestyle or nutrition therapies.
“There’s growing evidence to suggest that metabolites play a key role in bipolar and other psychiatric disorders,” Dr. Stacey says.
“This is extremely encouraging, because if we can find factors that connect certain health conditions, we can identify ways to negate these through potential lifestyle or dietary interventions.
“In this study, we found that a genetic propensity for higher levels of lipids containing arachidonic acid* led to a lower risk of bipolar disorder. And conversely, lower levels of arachidonic acid had a higher risk for bipolar disorder.
“Arachidonic acid can be sourced directly from meat and seafood products or synthesized from dietary linoleic acid (such as nuts, seeds, and oils). But it is also present in human milk, so it is considered essential for infant brain development.
“In fact, in many countries, arachidonic acid is added to infant formula to ensure a child gets the best start to life. So, there is certainly potential to boost this through supplements for people at greater risk of bipolar disorder.
“The challenge is, however, that while we know that arachidonic acid is involved in early brain development, it’s unclear whether supplementation for bipolar disorder should occur perinatally, during early life, or even whether it would benefit those already diagnosed.”
Professor Elina Hyppönen, who co-authored the study, believes that preclinical research and randomised controlled trials are necessary to evaluate the preventative or therapeutic effectiveness of arachidonic acid supplements in the treatment of bipolar disorder.
”We need further studies to rigorously assess the potential for arachidonic acid supplementation in bipolar disorder prevention and treatment, particularly in people who carry genetic risks. While our findings support potential avenues for precision health interventions for early life nutrition for babies’ brain development, we need to know more about the connection with bipolar disorder. If we can establish how, why and when people respond to arachidonic acid supplementation, then we will be one step closer to helping people who are struggling with this serious and lifelong mental health condition.”
Professor Elina Hyppönen
Source: University of South Australia
Journal reference:
Stacey, D., et al. (2024). A metabolome-wide Mendelian randomization study identifies dysregulated arachidonic acid synthesis as a potential causal risk factor for bipolar disorder. Biological Psychiatry. doi.org/10.1016/j.biopsych.2024.02.1005
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