Higher omega-3 levels linked to lower risk of depression, study finds

Analysis of genetic data from the UK Biobank and the Psychiatric Genomics Consortium has shown that people with higher levels of omega-3 fatty acids in their bodies are less likely to develop major depressive disorder . The strongest association with a lower risk of depression was found for eicosapentaenoic acid, a long-chain omega-3 fatty acid. These findings were published in the journal Translation of Psychiatry.

Omega-3 fatty acids are a group of essential polyunsaturated fats that are important for maintaining overall health. The three main types are alpha-linolenic acid (ALA), found in plant oils such as flaxseed and chia seeds, and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), found mainly in marine oils such as fish and algae. .

These fatty acids are important for brain function, reducing inflammation, and supporting heart health. Since the human body cannot make omega-3 fatty acids properly, they must be obtained from food or supplements. Studies have linked omega-3 fatty acids to many health benefits, including reducing the risk of chronic diseases such as heart disease and reducing symptoms of depression and anxiety.

Although ALA can be converted into other types of omega-3 fatty acids, these processes tend to be altered and ineffective due to the competition of metabolic pathways with other fatty acids, especially omega-6 fatty acids. .

Study author Rebecca Carnegie and her colleagues aimed to examine the relationship between omega-3 fatty acids in the body and recurrent depression, also known as major depressive disorder and episodes repeat yourself. This mental health condition is characterized by multiple episodes of depression over time, each lasting at least two weeks. These events include persistent feelings of sadness, loss of interest or pleasure in activities, changes in appetite or sleep, and problems with thinking or concentrating that significantly interfere with daily functioning.

The researchers conducted a Mendelian randomization study using data from two sources: the UK Biobank, which included 115,078 individuals, and the Psychiatric Genomics Consortium (PGC) genome-wide association studies (GWAS) of major disorders. of depression, which included 430,775 people, and recurrence. depression, which included 80,933 people.

They identified genetic variants associated with the metabolism, transport, and synthesis of omega-3 fatty acids in the body and used these variants to estimate levels of omega-3 fatty acids. Although omega-3 fatty acids are obtained mainly from food, the efficiency of their use and the levels in the body can be influenced by certain genetic factors.

Research studies have shown that people with higher genetic levels of omega-3 fatty acids had a lower risk of developing depression. On the other hand, higher genetic levels of omega-6 fatty acids were not associated with an increased risk of major depressive disorder. A similar trend was observed for recurrent depression: people with a genetic predisposition to omega-3 fatty acids were less likely to develop recurrent depression. The greatest effect on this risk reduction was due to eicosapentaenoic acid.

“Our results provide evidence of a genetic link between omega-3 fatty acids and MDD [major depressive disorder]. The effect appears to be strong for the EPA [eicosapentaenoic acid]it remains strong in biologically relevant lipids, and is not explained due to regression [it is omega-3 fatty acids that affect depression, not depression that affects omega-3 fatty acid levels],” the study authors concluded.

Although the study sheds light on the possible role of omega-3 fatty acids in depression, the observed effects were relatively small, indicating that the role of omega-3 fatty acids in the development of stress may be less. Additionally, the study’s focus on people of European descent may limit the generalizability of the findings to other populations. In addition, the optimal levels of EPA and DHA were not directly measured in all cases, requiring the use of representative data, which may produce some inaccuracy. The possibility of pleiotropy—where different genes influence multiple processes—also complicates the interpretation of causal relationships.

Future research may benefit from combining genetic data with detailed dietary analyzes to provide a more comprehensive understanding of how omega-3 fatty acids affect mental health. Further studies may also examine the differential effects of EPA and DHA on potential mediators, such as inflammation, to strengthen the rationale for the intervention of high levels of EPA. Because of the small effect sizes, future trials may consider targeting participants with higher omega-3 fatty acids or higher omega-6 to omega-3 ratios to produce benefits. many.

The paper, “Omega-3 fatty acids and major depression: a Mendelian randomization study,” was written by R. Carnegie, MC Borges, HJ Jones, J. Zheng, P. Haycock, J. Evans, and RM Martin.