Exercise and Nutrition in Persons with Dementia Review Article| Volume 21, ISSUE 10, P1402-1409, October 2020

Download started.


The Effect of Adherence to the Mediterranean Diet on Late-Life Cognitive Disorders: A Systematic Review



      Although some results are conflicting, numerous investigations have demonstrated that the Mediterranean Diet (MedDiet) has positive effects on brain health. This review intends to provide an update on the scientific evidence regarding the effects of adherence to the MedDiet on late-life cognitive disorders.


      A systematic review was performed. The PubMed and Scopus databases were searched for longitudinal studies and randomized controlled trials (RCTs) published between the databases’ inceptions and May 4, 2020. PRISMA guidelines were followed; the quality of the studies was assessed using version 2 of the Cochrane risk-of-bias tool for the RCTs and the Newcastle-Ottawa Scale for the longitudinal studies. The results are reported descriptively.

      Settings and Participants

      Middle-aged and older adults.


      The review's principal outcomes were cognitive decline, cognitive performance and function, Mild Cognitive Impairment (MCI), Alzheimer's disease (AD), and dementia.


      Forty-five of the 995 articles retrieved from the databases met our criteria. Seven were RCTs and 38 were longitudinal studies. Overall the studies showed that the MedDiet has some protective effects on cognitive decline. As far as cognition domains were concerned, the MedDiet was associated only with improved global cognition. The results were mixed for MCI and AD. There was no evidence that it has a beneficial effect on dementia.

      Conclusions and Implications

      The review's analysis confirmed that adherence to the MedDiet is associated with some improvement in cognitive health. The heterogeneity of the scoring systems assessing adherence to the MedDiet and of the modalities evaluating the cognitive outcomes has played no small role in the differences emerging in the results and has hindered efforts to interpret them. Although other interventional studies are warranted to confirm the efficacy of the MedDiet in preventing cognitive disorders, the results show that it can be considered part of a multifactorial approach to improve late-life cognitive function.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Journal of the American Medical Directors Association
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Prince M.
        • Wimo A.
        • Guerchet M.
        • et al.
        World Alzheimer Report 2015. The Global Impact of Dementia. An Analysis of Prevalence, Incidence, Cost and Trends.
        Alzheimer’s Disease International, London2015
        • Alzheimer's Association
        Alzheimer's disease facts and figures.
        Alzheimers Dement. 2016; 12: 459-509
        • World Health Organization and Alzheimer’s Disease International
        Dementia: A Public Health Priority.
        World Health Organization, Alzheimer’s Disease International, London2012
        • Norton S.
        • Matthews F.E.
        • Barnes D.E.
        • et al.
        Potential for primary prevention of Alzheimer's disease: An analysis of population-based data.
        Lancet Neurol. 2014; 13: 788-794
        • Gardener S.L.
        • Rainey-Smith S.R.
        The role of nutrition in cognitive function and brain ageing in the elderly.
        Curr Nutr Rep. 2018; 7: 139-149
        • Willett W.C.
        • Sacks F.
        • Trichopoulou A.
        • et al.
        Mediterranean diet pyramid: A cultural model for healthy eating.
        Am J Clin Nutr. 1995; 61: 1402S-1406S
        • Bianchi V.E.
        • Herrera P.F.
        • Laura R.
        Effect of nutrition on neurodegenerative diseases. A systematic review.
        Nutr Neurosci. 2019; : 1-25
        • Chen X.
        • Maguire B.
        • Brodaty H.
        • O'Leary F.
        Dietary patterns and cognitive health in older adults: A systematic review.
        J Alzheimers Dis. 2019; 67: 583-619
        • Hill E.
        • Goodwill A.M.
        • Gorelik A.
        • Szoeke C.
        Diet and biomarkers of Alzheimer's disease: A systematic review and meta-analysis.
        Neurobiol Aging. 2019; 76: 45-52
        • Yusufov M.
        • Weyandt L.L.
        • Piryatinsky I.
        Alzheimer's disease and diet: A systematic review.
        Int J Neurosci. 2017; 127: 161-175
        • Solfrizzi V.
        • Custodero C.
        • Lozupone M.
        • et al.
        Relationships of dietary patterns, foods, and micro- and macronutrients with Alzheimer's disease and late-life cognitive disorders: A systematic review.
        J Alzheimers Dis. 2017; 59: 815-849
        • Wu L.
        • Sun D.
        Adherence to Mediterranean diet and risk of developing cognitive disorders: An updated systematic review and meta-analysis of prospective cohort studies.
        Sci Rep. 2017; 7: 41317
        • Masana M.F.
        • Koyanagi A.
        • Haro J.M.
        • Tyrovolas S.
        n-3 Fatty acids, Mediterranean diet and cognitive function in normal aging: A systematic review.
        Exp Gerontol. 2017; 91: 39-50
        • Petersson S.D.
        • Philippou E.
        Mediterranean diet, cognitive function, and dementia: A systematic review of the evidence.
        Adv Nutr. 2016; 7: 889-904
        • Moher D.
        • Liberati A.
        • Tetzlaff J.
        • et al.
        PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement.
        BMJ. 2009; 339: b2535
        • Sterne J.A.C.
        • Savović J.
        • Page M.J.
        • et al.
        RoB 2: A revised tool for assessing risk of bias in randomised trials.
        BMJ. 2019; 366: l4898
        • Wells G.
        • Shea B.
        • O’connell D.
        • et al.
        The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomised studies in meta-analyses.
        (Available at:) (Published 2000)
        • Wardle J.
        • Rogers P.
        • Judd P.
        • et al.
        Randomized trial of the effects of cholesterol-lowering dietary treatment on psychological function.
        Am J Med. 2000 May; 108: 547-553
        • Martínez-Lapiscina E.H.
        • Clavero P.
        • Toledo E.
        • et al.
        Mediterranean diet improves cognition: The PREDIMED-NAVARRA randomised trial.
        J Neurol Neurosurg Psychiatry. 2013; 84: 1318-1325
        • Martínez-Lapiscina E.H.
        • Clavero P.
        • Toledo E.
        • et al.
        Virgin olive oil supplementation and long-term cognition: The PREDIMED-NAVARRA randomized, trial.
        J Nutr Health Aging. 2013; 17: 544-552
        • Martínez-Lapiscina E.H.
        • Galbete C.
        • Corella D.
        • et al.
        Genotype patterns at CLU, CR1, PICALM and APOE, cognition and Mediterranean diet: The PREDIMED-NAVARRA trial.
        Genes Nutr. 2014; 9: 393
        • Valls-Pedret C.
        • Sala-Vila A.
        • Serra-Mir
        • et al.
        Mediterranean Diet and age-related cognitive decline: A randomized clinical trial.
        JAMA Intern Med. 2015; 175: 1094-1103
        • Knight A.
        • Bryan J.
        • Wilson C.
        • et al.
        The Mediterranean diet and cognitive function among healthy older adults in a 6-month randomised controlled trial: The MedLey study.
        Nutrients. 2016; 8: 579
        • Marseglia A.
        • Xu W.
        • Fratiglioni L.
        • et al.
        Effect of the NU-AGE diet on cognitive functioning in older adults: A randomized controlled trial.
        Front Physiol. 2018; 9: 349
        • Scarmeas N.
        • Stern Y.
        • Tang M.X.
        • et al.
        Mediterranean diet and risk for Alzheimer's disease.
        Ann Neurol. 2006; 59: 912-921
        • Scarmeas N.
        • Luchsinger J.A.
        • Schupf N.
        • et al.
        Physical activity, diet, and risk of Alzheimer disease.
        JAMA. 2009; 302: 627-637
        • Scarmeas N.
        • Stern Y.
        • Mayeux R.
        • et al.
        Mediterranean diet and mild cognitive impairment.
        Arch Neurol. 2009; 66: 216-225
        • Féart C.
        • Samieri C.
        • Rondeau V.
        • et al.
        Adherence to a Mediterranean diet, cognitive decline, and risk of dementia.
        JAMA. 2009; 302: 638-648
        • Gu Y.
        • Luchsinger J.A.
        • Stern Y.
        • Scarmeas N.
        Mediterranean diet, inflammatory and metabolic biomarkers, and risk of Alzheimer's disease.
        J Alzheimers Dis. 2010; 22: 483-492
        • Roberts R.O.
        • Geda Y.E.
        • Cerhan J.R.
        • et al.
        Vegetables, unsaturated fats, moderate alcohol intake, and mild cognitive impairment.
        Dement Geriatr Cogn Disord. 2010; 29: 413-423
        • Tangney C.C.
        • Kwasny M.J.
        • Li H.
        • et al.
        Adherence to a Mediterranean-type dietary pattern and cognitive decline in a community population.
        Am J Clin Nutr. 2011; 93: 601-607
        • Vercambre M.N.
        • Grodstein F.
        • Berr C.
        • Kang J.H.
        Mediterranean diet and cognitive decline in women with cardiovascular disease or risk factors.
        J Acad Nutr Diet. 2012; 112: 816-823
        • Cherbuin N.
        • Anstey K.J.
        The Mediterranean diet is not related to cognitive change in a large prospective investigation: The PATH through life study.
        Am J Geriatr Psychiatry. 2012; 20: 635-639
        • Samieri C.
        • Okereke O.I.
        • Devore E.E.
        • Grodstein F.
        Long-term adherence to the Mediterranean diet is associated with overall cognitive status, but not cognitive decline, in women.
        J Nutr. 2013; 143: 493-499
        • Samieri C.
        • Grodstein F.
        • Rosner B.A.
        • et al.
        Mediterranean diet and cognitive function in older age.
        Epidemiology. 2013; 24: 490-499
        • Tsivgoulis G.
        • Judd S.
        • Letter A.J.
        • et al.
        Adherence to a Mediterranean diet and risk of incident cognitive impairment.
        Neurology. 2013; 80: 1684-1692
        • Wengreen H.
        • Munger R.G.
        • Cutler A.
        • et al.
        Prospective study of Dietary Approaches to Stop Hypertension- and mediterranean-style dietary patterns and age-related cognitive change: The Cache County Study on Memory, Health and Aging.
        Am J Clin Nutr. 2013; 98: 1263-1271
        • Kesse-Guyot E.
        • Andreeva V.A.
        • Lassale C.
        • et al.
        Mediterranean diet and cognitive function: A French study.
        Am J Clin Nutr. 2013; 97: 369-376
        • Tangney C.C.
        • Li H.
        • Wang Y.
        • et al.
        Relation of DASH- and Mediterranean-like dietary patterns to cognitive decline in older persons.
        Neurology. 2014; 83: 1410-1416
        • Olsson E.
        • Karlstroma B.
        • Kilanderb L.
        • et al.
        Dietary patterns and cognitive dysfunction in a 12-year follow-up study of 70 year old men.
        J Alzheimers Dis. 2015; 43: 109-119
        • Koyama A.
        • Houston D.K.
        • Simonsick E.M.
        • et al.
        Association between the Mediterranean diet and cognitive decline in a biracial population.
        J Gerontol A Biol Sci Med Sci. 2015; 70: 354-359
        • Gardener S.L.
        • Rainey-Smith S.R.
        • Barnes M.B.
        • et al.
        Dietary patterns and cognitive decline in an Australian study of ageing.
        Mol Psychiatry. 2015; 20: 860-866
        • Galbete C.
        • Toledo E.
        • Toledo J.B.
        • et al.
        Mediterranean diet and cognitive function: The sun project.
        J Nutr Health Aging. 2015; 19: 305-312
        • Trichopoulou A.
        • Kyrozis A.
        • Rossi M.
        • et al.
        Mediterranean diet and cognitive decline over time in an elderly Mediterranean population.
        Eur J Nutr. 2015; 54: 1311-1321
        • Qin B.
        • Adair L.S.
        • Plassman B.L.
        • et al.
        Dietary patterns and cognitive decline among Chinese older adults.
        Epidemiology. 2015; 26: 758-768
        • Morris M.C.
        • Tangney C.C.
        • Wang Y.
        • et al.
        MIND diet associated with reduced incidence of Alzheimer's disease.
        Alzheimers Dement. 2015; 11: 1007-1014
        • Haring B.
        • Wu C.
        • Mossavar-Rahmani Y.
        • et al.
        No association between dietary patterns and risk for cognitive decline in older women with 9-year follow-up: Data from the women’s health initiative memory study.
        J Acad Nutr Diet. 2016; 116: 921-930.e1
        • Walters M.J.
        • Sterling J.
        • Quinn C.
        • et al.
        Associations of lifestyle and vascular risk factors with Alzheimer's brain biomarker changes during middle age: A 3-year longitudinal study in the broader New York City area.
        BMJ Open. 2018; 8: e023664
        • Bhushan A.
        • Fondell E.
        • Ascherio A.
        • et al.
        Adherence to Mediterranean diet and subjective cognitive function in men.
        Eur J Epidemiol. 2018; 33: 223-234
        • Richard E.L.
        • Laughlin G.A.
        • Kritz-Silverstein D.
        • et al.
        Dietary patterns and cognitive function among older community-dwelling adults.
        Nutrients. 2018; 10: E1088
        • Larsson S.C.
        • Wolk A.
        The role of lifestyle factors and sleep duration for late-onset dementia: A cohort study.
        J Alzheimers Dis. 2018; 66: 579-586
        • Shakersain B.
        • Rizzuto D.
        • Larsson S.C.
        • et al.
        The Nordic Prudent Diet reduces risk of cognitive decline in the Swedish older adults: A population-based cohort study.
        Nutrients. 2018; 10: E229
        • Tanaka T.
        • Talegawkar S.A.
        • Jin Y.
        • et al.
        Adherence to a Mediterranean diet protects from cognitive decline in the Invecchiare in Chianti Study of Aging.
        Nutrients. 2018; 10: E2007
        • Wade A.T.
        • Elias M.F.
        • Murphy K.J.
        Adherence to a Mediterranean diet is associated with cognitive function in an older non-Mediterranean sample: Findings from the Maine-Syracuse Longitudinal Study.
        Nutr Neurosci. 2019; 21: 1-12
        • Mattei J.
        • Bigornia S.J.
        • Sotos-Prieto M.
        • et al.
        The Mediterranean diet and 2-year change in cognitive function by status of type 2 diabetes and glycemic control.
        Diabetes Care. 2019; 42: 1372-1379
        • Hosking D.E.
        • Eramudugolla R.
        • Cherbuin N.
        • Anstey K.J.
        MIND not Mediterranean diet related to 12-year incidence of cognitive impairment in an Australian longitudinal cohort study.
        Alzheimers Dement. 2019; 15: 581-589
        • Shannon O.M.
        • Stephan B.C.M.
        • Granic A.
        • et al.
        Mediterranean diet adherence and cognitive function in older UK adults: The European Prospective Investigation into Cancer and Nutrition-Norfolk (EPIC-Norfolk) Study.
        Am J Clin Nutr. 2019; 110: 938-948
        • Wagner M.
        • Grodstein F.
        • Proust-Lima C.
        • et al.
        Long-term trajectories of body weight, diet, and physical activity from midlife through late-life and subsequent cognitive decline in women.
        Am J Epidemiol. 2020; 189: 305-313
        • Wu J.
        • Song X.
        • Chen G.C.
        • et al.
        Dietary pattern in midlife and cognitive impairment in late life: A prospective study in Chinese adults.
        Am J Clin Nutr. 2019; 110: 912-920
        • Munoz-Garcia M.I.
        • Toledo E.
        • Razquin C.
        • et al.
        “A priori” dietary patterns and cognitive function in the SUN Project.
        Neuroepidemiology. 2020; 54: 45-57
        • Keenan T.D.
        • Agrón E.
        • Mares J.A.
        • et al.
        Adherence to a Mediterranean diet and cognitive function in the age-related eye disease studies 1 & 2.
        Alzheimers Dement. 2020; 16: 831-842
        • Lutski M.
        • Weinstein G.
        • Ben-Zvi S.
        • et al.
        Adherence to Mediterranean diet and subsequent cognitive decline in men with cardiovascular disease.
        Nutr Neurosci. 2020 Jan 22; ([Epub ahead of print.])
        • Trichopoulou A.
        • Costacou T.
        • Bamia C.
        • Trichopoulos D.
        Adherence to a Mediterranean diet and survival in a Greek population.
        N Engl J Med. 2003; 348: 2599-2608
        • Panagiotakos D.B.
        • Pitsavos C.
        • Stefanadis C.
        Dietary patterns: A Mediterranean diet score and its relation to clinical and biological markers of cardiovascular disease risk.
        Nutr Metab Cardiovasc Dis. 2006; 16: 559-568
        • Fung T.T.
        • McCullough M.L.
        • Newby P.K.
        • et al.
        Diet-quality scores and plasma concentrations of markers of inflammation and endothelial dysfunction.
        Am J Clin Nutr. 2005; 82: 163-173
        • Estruch R.
        • Martínez-González M.A.
        • Corella D.
        • et al.
        • PREDIMED Study Investigators
        Effects of a Mediterranean-style diet on cardiovascular risk factors: A randomized trial.
        Ann Intern Med. 2006; 145: 1-11
        • Tong T.Y.
        • Wareham N.J.
        • Khaw K.T.
        Prospective association of the Mediterranean diet with cardiovascular disease incidence and mortality and its population impact in a non-Mediterranean population: The EPIC-Norfolk study.
        BMC Med. 2016; 14: 135
        • Rumawas M.E.
        • Dwyer J.T.
        • McKeown N.M.
        • et al.
        The development of the Mediterranean-style dietary pattern score and its application to the American diet in the Framingham Offspring Cohort.
        J Nutr. 2009; 139: 1150-1156
        • Sofi F.
        • Macchi C.
        • Abbate R.
        • et al.
        Mediterranean diet and health status: An updated meta-analysis and a proposal for a literature-based adherence score.
        Public Health Nutr. 2014; 17: 2769-2782
        • Folstein M.F.
        • Folstein S.E.
        • McHugh P.R.
        “Mini-Mental State”: A practical method for grading the cognitive state of patients for the clinician.
        J Psychiatr Res. 1975; 12: 189-198
        • Freedman M.
        • Leach L.
        • Kaplan E.
        • et al.
        Clock Drawing: A Neuropsychological Analysis.
        1st Ed. Oxford University Press, New York1994
        • Teng E.L.
        • Chui H.C.
        The Modified Mini-Mental State (3MS) examination.
        J Clin Psychiatry. 1987; 48: 314-318
        • Brandt J.
        • Spencer M.
        • Folstein M.
        The Telephone Interview for Cognitive Status.
        Neuropsychiatry Neuropsychol Behav Neurol. 1988; 1: 111-117
        • Callahan C.M.
        • Unverzagt F.W.
        • Hui S.L.
        Six-item screener to identify cognitive impairment among potential subjects for clinical research.
        Med Care. 2002; 40: 771-781
        • Winblad B.
        • Palmer K.
        • Kivipelto M.
        • et al.
        Mild cognitive impairment—beyond controversies, towards a consensus: Report of the International Working Group on Mild Cognitive Impairment.
        J Intern Med. 2004; 256: 240-246
        • Petersen R.C.
        Mild cognitive impairment as a diagnostic entity.
        J Intern Med. 2004; 256: 183-194
        • American Psychiatric Association
        Diagnostic and Statistical Manual of Mental Disorders. 3rd ed revised.
        APA Press, Washington, DC1987
        • American Psychiatric Association
        Diagnostic and Statistical Manual of Mental Disorders.
        Washington DC. 4th ed. APA Press, 1994
        • McKhann G.
        • Drachman D.
        • Folstein M.
        • et al.
        Clinical diagnosis of Alzheimer’s disease: Report of the NINCDS-ADRDA Work Group under the auspices of Department of Health and Human Services Task Force on Alzheimer’s Disease.
        Neurology. 1984; 34: 939-944
        • Roman G.C.
        • Tatemichi T.K.
        • Erkinjuntti T.
        • et al.
        Vascular dementia: Diagnostic criteria for research studies. Report of the NINDS-AIREN International Workshop.
        Neurology. 1993; 43: 250-260
        • Knight A.
        • Bryan J.
        • Murphy K.
        The Mediterranean diet and age-related cognitive functioning: A systematic review of study findings and neuropsychological assessment methodology.
        Nutr Neurosci. 2017; 20: 449-468
        • Mitchell A.J.
        • Beaumont H.
        • Ferguson D.
        • et al.
        Risk of dementia and mild cognitive impairment in older people with subjective memory complaints: Meta-analysis.
        Acta Psychiatr Scand. 2014; 130: 439-451
        • Baumgart M.
        • Snyder H.M.
        • Carrillo M.C.
        • et al.
        Summary of the evidence on modifiable risk factors for cognitive decline and dementia: A population-based perspective.
        Alzheimers Dement. 2015; 11: 718-726
        • Hernández-Ruiz A.
        • García-Villanova B.
        • Guerra Hernández E.J.
        • et al.
        Description of indexes based on the adherence to the Mediterranean dietary pattern: A review.
        Nutr Hosp. 2015; 32: 1872-1884
        • Shim J.S.
        • Oh K.
        • Kim H.C.
        Dietary assessment methods in epidemiologic studies.
        Epidemiol Health. 2014; 36: e2014009
        • Ioannidis J.P.A.
        The challenge of reforming nutritional epidemiologic research.
        JAMA. 2018; 320: 969-970
        • McGrattan M.A.
        • McGuinness B.
        • McKinley M.C.
        • et al.
        Diet and inflammation in cognitive ageing and Alzheimer’s disease.
        Curr Nutr Rep. 2019; 8: 53-65
        • Sofi F.
        • Macchi C.
        • Abbate R.
        • et al.
        Effectiveness of the Mediterranean diet: Can it help delay or prevent Alzheimer's disease?.
        J Alzheimers Dis. 2010; 20: 795-801
        • Ouwehand A.C.
        • Bergsma N.
        • Parhiala R.
        • et al.
        Bifidobacterium microbiota and parameters of immune function in elderly subjects.
        FEMS Immunol Med Microbiol. 2008; 53: 18-25
        • Filippis F.
        • Pellegrini N.
        • Vannini L.
        • et al.
        High-level adherence to a Mediterranean diet beneficially impacts the gut microbiota and associated metabolome.
        Gut. 2016; 65: 1812-1821