Effects of Omega-3 Polyunsaturated Fatty Acids on Brain Functions: A Systematic Review

Abstract

Omega is a polyunsaturated fatty acid (PUFA) that has an essential impact on cognitive performance at all stages of life. Eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA) are essential for brain functions. DHA, the dominant omega-3 in the brain, impacts neurotransmitters and functions of the brain. This systematic review aimed to assess the effects of omega-3 on brain functions. We searched for articles from 2010 to 2022 in PubMed, electronic databases: discover, academic search complete (EBSCO), and Cochrane. To increase search efficiency, search terms include database-specific indexed phrases and keywords. Search terms included "omega three," "DHA," "fish oil," "eicosapentaenoic acid," "EPA," "docosahexaenoic acid," "omega-3," "cognition," "brain," "mental health," and "PUFAs". We conducted a review of only randomized clinical trials (RCTs) that were published in English. We evaluated the quality of the studies using the Cochrane Collaboration bias assessment tool. Our search strategy yielded 174 articles, out of which 33 full-text articles were reviewed and nine articles were selected for data abstraction. The overall number of individuals in all nine studies was 1319. Of the participants, 591 (44.81%) were men, and 728 (55.19%) were women. Participants who received omega-3 were 700 (65.06%) compared to 376 (34.94%) who received a placebo, and their mean age was 45. Ingestion of omega-3 fatty acids increases learning, memory, cognitive well-being, and blood flow in the brain. Omega-3 treatments are advantageous, welltolerated, and risk-free. Lonelier people, the elderly, and those who eat fewer healthy foods containing omega-3 may benefit from an omega-3 supplement. We suggest that natural omega-3 consumption through the diet should be promoted.

Omega-3 PUFAs as a Dietary Supplement in Senile Systemic Amyloidosis

“…A few years later, EPA and DHA were used as supplements in AD patients, and also in this case, the TTR levels of expression increased significantly [ 60 ]. Therefore, for elderly people, the daily use of EPA and DHA can reflect an improvement in cognitive performance, as previously demonstrated [ 6 ], and also in positive effects mediated by TTR actions, inducing the TTR production and contributing to maintaining its tetrameric structure.…”

“…Moreover, they have healthy effects on brain functions. Indeed, they showed to improve cognitive performances in terms of increasing learning, memory, and blood flow in the brain [ 6 ], and to ameliorate conditions for subjects with neurodegenerative disorders, such as Alzheimer’s and Parkinson’s diseases, (AD and PD, respectively) [ 7 , 8 , 9 ]. Some interesting evidence has also suggested a possible direct interaction between omega-3 fatty acids and proteins that are involved in neurodegenerative processes, i.e., β-amyloid for AD [ 10 ], α-synuclein in PD [ 11 ], and transthyretin (TTR) in TTR amyloidosis (ATTR) [ 12 ].…”

Lipid emulsions in parenteral nutrition: does it matter?

“…Favorable effects were also observed in a small cohort of longer-term HPN patients when using 4-OLE compared with previous use of a pure SO-ILE [37]. An added benefit of the omega-3 fatty acid ILEs found in FO is that they increase learning, memory, cognitive well being, and blood flow to the brain [38 ▪ ]. It is also clearly proven that pure FO-LE in PN reduce, and in fact can reverse, the occurrence of cholestasis in very low birth weight and preterm infants [5 ▪▪ ,39 ▪▪ ,40 ▪ ,41].…”

Effect of basal insulin and omega 3 fatty acids on cognitive impairment in dysglycaemia: An exploratory analysis of the ORIGIN trial

“…39,40 Indeed a recent systematic review in younger individuals reported that supplementation with omega 3 FAs increased learning memory and blood flow in the brain. 41 The absence of an effect in these analyses may be because of the clinical features of this older study population or the dose used.…”