Omega-3 may be an “effective add-on therapeutic” for depression: study

The review also observed a direct relationship between the polyunsaturated fatty acids (PUFAs) dosage and the effect size on depression, with eicosapentaenoic acid (EPA) demonstrating a greater effect over docosahexaenoic acid (DHA).

Regarding the ‘British Journal of Nutrition’ published findings, the Chinese researchers conclude: “Omega-3 PUFAs supplementation could be considered as an effective therapeutic adjuvant approach in relieving depression symptoms.”

Omegas and the mind​

Depression is a highly common condition of the modern world, affecting an array of areas​ such as sleep quality, energy levels, and appetite. The World Health Organization has previously predicted​ that it may affect 280 million people globally, with levels ever-increasing​ following the Covid-19 pandemic.

Research​ has shown that factors such as nutrition, genetics, environment, and hormones play major roles in the pathogenesis of depression, with alterations noted in the levels of serotonin, dopamine, and gamma -aminobutyric acid (GABA).

Following long-term concerns​ around the effectiveness and adversities associated with the use of anti-depressants, there has been significant interest in investigating further causes of depression and more natural treatment methods. It is known that long-chain fatty acids (n-3 PUFAs), specifically EPA and DHA, have significant benefits​ such as anti-inflammatory and subsequent neuro-inflammatory inhibitory activities.

Whilst previous meta-analyses​ have investigated the association between omega-3 FAs and depression, there has been a lack of a reached conclusive outcomes. Thus, the researchers conducted an umbrella review of such meta-analyses to further establish a definite conclusion.

Review findings​

The researchers searched the databases of PubMed, Scopus, Embase, Web of Science, and Cochrane Central Library to collate meta-analyses investigating the effects of n-3 PUFAs on depressive symptoms. Twenty-two meta-analyses were included following the search.

The findings revealed a significant improvement effect on depressive symptoms in the majority of included studies, with 16 effect sizes displaying this association.

Supplement dosages displaying significant effects ranged from 0.09-3.4g of DHA and 0.009-6.2 g of EPA.

The association was observed to be more pronounced in those with major depressive disorder (MDD), when compared to those with mild or normal depressive symptoms. Furthermore, there was a direct relationship between the dosages of omega-3 PUFAs and the effect size on depression, with EPA demonstrating a greater effect over DHA.

Explained​

Based on the findings, the report concluded that omega-3 supplements may present an efficacious add-on therapeutic approach in relieving depression symptoms.

Explaining the mechanism of action, the researchers said: “Omega-3 PUFAs have been proven to influence the activity and structure of brain through affecting adult neurogenesis and synaptogenesis by increasing the signalling factors involved in neurogenesis, such as brain-derived neurotrophic factor (BDNF), cAMP response element-binding protein (CREB), or calcium/calmodulin-dependent protein kinase II (CaMKII).

“In one pathway, omega-3 PUFAs might increase the expression of dopamine receptor; whereby increase dopamine activity as a neurotransmiter in restoring the mood (81). As well, omega-3 PUFAs were effective in balancing the low level of BDNF (brain-derived neurotrophic factor) among depressed patients. BDNF could boost the action of antidepressant agents,” they added.

Yet, the report emphasised the need for further research to account for significant between-study heterogeneity and a lack of insight into factors such as dose, duration of supplementation and gender.

Source: British Journal of Nutrition

https://doi.org/10.1017/S000711452300226X​

“Clinical impacts of omega-3 fatty acids supplementation on depression symptoms: An umbrella review of meta-analyses”

Yi Lu, Dongdong Qiao and Guolin Mi