Associations and effects of omega-3 polyunsaturated fatty acids on cognitive function and mood in healthy adults: a protocol for a systematic review of observational and interventional studies

Fiona O' Donovan, Síle Carney, Jean Kennedy, Heather Hayes, Niall Pender, Fiona Boland, Alice Stanton, Fiona O' Donovan, Síle Carney, Jean Kennedy, Heather Hayes, Niall Pender, Fiona Boland, Alice Stanton

Abstract

Introduction: The association between long-chain omega-3 polyunsaturated fatty acids (PUFAs), brain health, cognitive function and mood has been the subject of intensive research. Marine-derived omega-3 PUFAs, such as docosahexaenoic acid and eicosapentaenoic acid, are highly concentrated in neuronal membranes and affect brain function. Many studies have found that consumption of omega-3 PUFAs is associated with lower risk of cognitive or mood dysfunction. However, other studies have demonstrated no beneficial effects. There appears to be inconsistent findings from both epidemiological and randomised controlled trial (RCT) studies. The aim of this review is to compile the previous literature and establish the efficacy of omega-3 PUFAs in enhancing cognitive performance and mood in healthy adults.

Methods and analysis: Prospective cohort studies, RCTs, controlled clinical trials, controlled before and after studies, interrupted time series with a minimum of 3 months duration will be eligible for inclusion. Studies on healthy adults over the age of 18, where the intervention/exposure of interest is omega-3 PUFAs will be included. The outcomes of interest are cognition and mood. Studies will be eligible for inclusion if they measure changes in cognitive function or mood, or the risk of developing cognitive or mood disorders using validated tools and assessments. Relevant search terms and keywords will be used to generate a systematic search in Cochrane Library, MEDLINE, EMBASE, PsycINFO, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Scopus and the grey literature. Two independent reviewers will screen studies for eligibility. Risk of bias in cohort and non-randomised studies will be assessed using the ROBINS-I tool. The Cochrane Collaboration's tool for assessing risk of bias in randomised trials will be used for RCTs. If there are sufficient data, a meta-analysis will be conducted.

Ethics and dissemination: This systematic review does not involve primary data collection and therefore formal ethical approval is not required. Results will be disseminated through peer reviewed publications, conference presentations and the popular press.

Prospero registration number: CRD42018080800.

Keywords: cognition; docosahexaenoic acid; fish; mood; omega-3 fatty acids.

Conflict of interest statement

Competing interests: Several team members are affiliated with Devenish Nutrition, a company that is involved in the production of omega-3 PUFA-enriched food products. FOD is a PhD student funded by the Irish Research Council Employment Based Postgraduate scheme in partnership with Devenish Nutrition. HH is Food Innovation Director with Devenish Nutrition. JK is Food Innovation Manager with Devenish Nutrition. AS works with and has ownership interest with Devenish Nutrition.

© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

References

    1. Ruxton CH, Reed SC, Simpson MJ, et al. . The health benefits of omega-3 polyunsaturated fatty acids: a review of the evidence. J Hum Nutr Diet 2004;17:449–59. 10.1111/j.1365-277X.2004.00552.x
    1. Bourre JM, Dumont O, Piciotti M, et al. . Essentiality of omega 3 fatty acids for brain structure and function. World Rev Nutr Diet 1991;66:103–17.
    1. Yehuda S, Rabinovitz S, Mostofsky DI. Essential fatty acids are mediators of brain biochemistry and cognitive functions. J Neurosci Res 1999;56:565–70. 10.1002/(SICI)1097-4547(19990615)56:6<565::AID-JNR2>;2-H
    1. Dyall SC. Long-chain omega-3 fatty acids and the brain: a review of the independent and shared effects of EPA, DPA and DHA. Front Aging Neurosci 2015;7:52 10.3389/fnagi.2015.00052
    1. Innis SM. Dietary (n-3) fatty acids and brain development. J Nutr 2007;137:855–9. 10.1093/jn/137.4.855
    1. Calder PC. Polyunsaturated fatty acids and inflammation. Prostaglandins Leukot Essent Fatty Acids 2006;75:197–202. 10.1016/j.plefa.2006.05.012
    1. Farooqui AA, Horrocks LA, Farooqui T. Modulation of inflammation in brain: a matter of fat. J Neurochem 2007;101:577–99. 10.1111/j.1471-4159.2006.04371.x
    1. Wang Q, Liang X, Wang L, et al. . Effect of omega-3 fatty acids supplementation on endothelial function: a meta-analysis of randomized controlled trials. Atherosclerosis 2012;221:536–43. 10.1016/j.atherosclerosis.2012.01.006
    1. Bazan NG. Omega-3 fatty acids, pro-inflammatory signaling and neuroprotection. Curr Opin Clin Nutr Metab Care 2007;10:136–41. 10.1097/MCO.0b013e32802b7030
    1. Calon F, Lim GP, Yang F, et al. . Docosahexaenoic acid protects from dendritic pathology in an Alzheimer’s disease mouse model. Neuron 2004;43:633–45. 10.1016/j.neuron.2004.08.013
    1. Muldoon MF, Ryan CM, Yao JK, et al. . Long-chain omega-3 fatty acids and optimization of cognitive performance. Mil Med 2014;179(11 Suppl):95–105. 10.7205/MILMED-D-14-00168
    1. Bozzatello P, Brignolo E, De Grandi E, et al. . Supplementation with omega-3 fatty acids in psychiatric disorders: a review of literature data. J Clin Med 2016;5:67 10.3390/jcm5080067
    1. Pusceddu MM, Kelly P, Stanton C, et al. . N-3 polyunsaturated fatty acids through the lifespan: implication for psychopathology. Int J Neuropsychopharmacol 2016;19:pyw078 10.1093/ijnp/pyw078
    1. Abubakari AR, Naderali MM, Naderali EK. Omega-3 fatty acid supplementation and cognitive function: are smaller dosages more beneficial? Int J Gen Med 2014;7:463–73. 10.2147/IJGM.S67065
    1. Cooper RE, Tye C, Kuntsi J, et al. . Omega-3 polyunsaturated fatty acid supplementation and cognition: a systematic review and meta-analysis. J Psychopharmacol 2015;29:753–63. 10.1177/0269881115587958
    1. Burckhardt M, Herke M, Wustmann T, et al. . Omega-3 fatty acids for the treatment of dementia. Cochrane Database Syst Rev 2016;4:Cd009002 10.1002/14651858.CD009002.pub3
    1. Sydenham E, Dangour AD, Lim W-S. Omega 3 fatty acid for the prevention of cognitive decline and dementia. Cochrane Database Syst Rev 2012;6:CD005379.
    1. Mazereeuw G, Lanctôt KL, Chau SA, et al. . Effects of ω-3 fatty acids on cognitive performance: a meta-analysis. Neurobiol Aging 2012;33:1482.e17–29. 10.1016/j.neurobiolaging.2011.12.014
    1. Issa AM, Mojica WA, Morton SC, et al. . The efficacy of omega-3 fatty acids on cognitive function in aging and dementia: a systematic review. Dement Geriatr Cogn Disord 2006;21:88–96. 10.1159/000090224
    1. Canhada S, Castro K, Perry IS, et al. . Omega-3 fatty acids' supplementation in Alzheimer’s disease: a systematic review. Nutr Neurosci 2018;21:529–38. 10.1080/1028415X.2017.1321813
    1. Appleton KM. Omega-3 fatty acids for depression in adults. Cochrane Database Syst Rev 2015;11:Cd004692.
    1. Bae JH, Kim G. Systematic review and meta-analysis of omega-3-fatty acids in elderly patients with depression. Nutr Res 2018;50:1–9. 10.1016/j.nutres.2017.10.013
    1. Forbes SC, Holroyd-Leduc JM, Poulin MJ, et al. . Effect of nutrients, dietary supplements and vitamins on cognition: a systematic review and meta-analysis of randomized controlled trials. Can Geriatr J 2015;18:231–45. 10.5770/cgj.18.189
    1. Jiao J, Li Q, Chu J, et al. . Effect of n-3 PUFA supplementation on cognitive function throughout the life span from infancy to old age: a systematic review and meta-analysis of randomized controlled trials. Am J Clin Nutr 2014;100:1422–36. 10.3945/ajcn.114.095315
    1. Rangel-Huerta OD, Gil A. Effect of omega-3 fatty acids on cognition: an updated systematic review of randomized clinical trials. Nutr Rev 2018;76:1–20. 10.1093/nutrit/nux064
    1. Rothwell PM. Factors that can affect the external validity of randomised controlled trials. PLoS Clin Trials 2006;1:e9 10.1371/journal.pctr.0010009
    1. Stark KD, Van Elswyk ME, Higgins MR, et al. . Global survey of the omega-3 fatty acids, docosahexaenoic acid and eicosapentaenoic acid in the blood stream of healthy adults. Prog Lipid Res 2016;63:132–52. 10.1016/j.plipres.2016.05.001
    1. Micha R, Khatibzadeh S, Shi P, et al. . Global, regional, and national consumption levels of dietary fats and oils in 1990 and 2010: a systematic analysis including 266 country-specific nutrition surveys. BMJ 2014;348:g2272 10.1136/bmj.g2272
    1. Olesen J, Gustavsson A, Svensson M, et al. . The economic cost of brain disorders in Europe. Eur J Neurol 2012;19:155–62. 10.1111/j.1468-1331.2011.03590.x
    1. Alzheimer’s Disease International, Policy Brief for G8 Heads of Government. The Global Impact of Dementia 2013-2050. London, UK, 2013.
    1. Steel Z, Marnane C, Iranpour C, et al. . The global prevalence of common mental disorders: a systematic review and meta-analysis 1980-2013. Int J Epidemiol 2014;43:476–93. 10.1093/ije/dyu038
    1. Moher D, Shamseer L, Clarke M, et al. . Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015 statement. Syst Rev 2015;4:1 10.1186/2046-4053-4-1
    1. Shamseer L, Moher D, Clarke M, et al. . Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015: elaboration and explanation. BMJ 2015;349:g7647 10.1136/bmj.g7647
    1. Arterburn LM, Hall EB, Oken H. Distribution, interconversion, and dose response of n−3 fatty acids in humans. Am J Clin Nutr 2006;83:1467S–76. 10.1093/ajcn/83.6.1467S
    1. Folstein MF, Folstein SE, McHugh PR. "Mini-mental state". A practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res 1975;12:189–98.
    1. Drozdick LW. The Wechsler Adult Intelligence Scale—Fourth Edition and the Wechsler Memory Scale—Fourth Edition, in Contemporary intellectual assessment: Theories, tests, and issues. 3rd ed New York, NY, US: Guilford Press, 2012:197–223.
    1. Zigmond AS, Snaith RP. The hospital anxiety and depression scale. Acta Psychiatr Scand 1983;67:361–70. 10.1111/j.1600-0447.1983.tb09716.x
    1. Beck AT, Steer RA, Brown GK. Manual for the beck depression inventory-II. San Antonio, TX: Psychological Corporation, 1996.
    1. Holman RT. The slow discovery of the importance of ω3 essential fatty acids in human health. J Nutr 1998;128:427S–33. 10.1093/jn/128.2.427S
    1. The Cochrane Collaboration,. Review manager (RevMan). Copenhagen: The Nordic Cochrane Centre, 2014.
    1. StataCorp. Stata statistical software: release 15. College Station, TX: StataCorp LLC, 2017.
    1. Faraone SV. Interpreting estimates of treatment effects: implications for managed care. P T 2008;33:700–11.
    1. Ryan R. Heterogeneity and subgroup analyses in Cochrane Consumers and Communication Review Group reviews: Planning the analysis at protocol stage Heterogeneity, 2014.
    1. Jakobsen JC, Wetterslev J, Winkel P, et al. . Thresholds for statistical and clinical significance in systematic reviews with meta-analytic methods. BMC Med Res Methodol 2014;14:120 10.1186/1471-2288-14-120
    1. Furukawa TA, Barbui C, Cipriani A, et al. . Imputing missing standard deviations in meta-analyses can provide accurate results. J Clin Epidemiol 2006;59:7–10. 10.1016/j.jclinepi.2005.06.006
    1. Egger M, Davey Smith G, Schneider M, et al. . Bias in meta-analysis detected by a simple, graphical test. BMJ 1997;315:629–34. 10.1136/bmj.315.7109.629
    1. Liberati A, Altman DG, Tetzlaff J, et al. . The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate healthcare interventions: explanation and elaboration. BMJ 2009;339:b2700 10.1136/bmj.b2700
    1. Moher D, Liberati A, Tetzlaff J, et al. . Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. Ann Intern Med 2009;151:264 10.7326/0003-4819-151-4-200908180-00135

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