Omega-3 fatty acids for brain health

Omega-3 fatty acids have a range of health benefits which are well documented, and research suggests these benefits may extend to brain health.

What are omega-3 fatty acids?

Omega-3 fatty acids are essential, meaning that we must obtain them from our diet. There are three main classes of omega-3 fatty acids:

1. α-linolenic acid (ALA),
2. eicosapentaenoic acid (EPA), and
3. docosahexaenoic acid (DHA).

The link between omega-3s and brain health

DHA is the predominant type of omega-3 that is found in the brain, over 90%, and is needed to carry out functions including synthesising anti-inflammatory mediators, cell membrane fluidity, gene expression, and other biochemical functions which support neurotransmission [1, 2].

What does the research say?

There is growing evidence that omega-3 fatty acids can support brain health. One 2022 systematic review found that omega-3 treatment increases markers of brain function including memory, cognitive well-being and led to increased blood flow to the brain [3].

Additionally, research suggests that increased consumption of omega-3s can protect against cognitive decline [4]. Specifically, there is growing research that supplementation of omega-3 fatty acids may help to slow the cognitive decline in neurodegenerative disorders such as Parkinson’s and Alzheimer’s disease [1].

For patients concerned with mental well-being, there is also research that has found associations between omega-3 fatty acid intake and reduced symptoms of anxiety and depression. For example, a 2023 systematic review and meta-analysis found that with high omega-3 fatty acids interventions, patients saw a significant reduction in severity of depression [5].

Where are omega-3 fatty acids found?

Dietary sources include oily fish, vegetable oils, flaxseeds, walnuts. Plant sources contain ALA which has a low conversion rate to DHA (below 5%), whereas oily fish are rich in DHA. Those who do not consume fish regularly may have a lower intake of omega-3 fatty acids and are more likely to benefit from taking an omega-3 supplement [3]. Options available include fish oil or omega-3 fatty acids derived from algae which are suitable for vegans and vegetarians [6].

Research suggests that omega-3s can support markers of brain health such as reducing cognitive decline, improving memory, and increasing cognitive well-being. Healthy dietary patterns, such as the Mediterranean diet, which emphasises foods rich in omega-3s, are an excellent way for patients to increase their intake of omega-3s.

– Sarah Marko, Accredited Practising Dietitian

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References

[1] Avallone R, Vitale G, Bertolotti M. Omega-3 Fatty Acids and Neurodegenerative Diseases: New Evidence in Clinical Trials. Int J Mol Sci. 2019 Aug 30;20(17):4256. doi: 10.3390/ijms20174256. PMID: 31480294; PMCID: PMC6747747.
[2] de Bus I, Witkamp R, Zuilhof H, Albada B, Balvers M. The role of n-3 PUFA-derived fatty acid derivatives and their oxygenated metabolites in the modulation of inflammation. Prostaglandins Other Lipid Mediat. 2019 Oct;144:106351. doi: 10.1016/j.prostaglandins.2019.106351. Epub 2019 Jun 28. PMID: 31260750.
[3] Dighriri IM, Alsubaie AM, Hakami FM, Hamithi DM, Alshekh MM, Khobrani FA, Dalak FE, Hakami AA, Alsueaadi EH, Alsaawi LS, Alshammari SF, Alqahtani AS, Alawi IA, Aljuaid AA, Tawhari MQ. Effects of Omega-3 Polyunsaturated Fatty Acids on Brain Functions: A Systematic Review. Cureus. 2022 Oct 9;14(10):e30091. doi: 10.7759/cureus.30091. PMID: 36381743; PMCID: PMC9641984.
[4] Loong S, Barnes S, Gatto NM, Chowdhury S, Lee GJ. Omega-3 Fatty Acids, Cognition, and Brain Volume in Older Adults. Brain Sciences. 2023; 13(9):1278. https://doi.org/10.3390/brainsci13091278
[5] Kelaiditis CF, Gibson EL, Dyall SC. Effects of long-chain omega-3 polyunsaturated fatty acids on reducing anxiety and/or depression in adults; A systematic review and meta-analysis of randomised controlled trials. Prostaglandins Leukot Essent Fatty Acids. 2023 May;192:102572. doi: 10.1016/j.plefa.2023.102572. Epub 2023 Apr 2. PMID: 37028202.
[6] Lane KE, Wilson M, Hellon TG, Davies IG. Bioavailability and conversion of plant based sources of omega-3 fatty acids - a scoping review to update supplementation options for vegetarians and vegans. Crit Rev Food Sci Nutr. 2022;62(18):4982-4997. doi: 10.1080/10408398.2021.1880364. Epub 2021 Feb 12. PMID: 33576691.