Mild Cognitive Impairment (MCI)

Last Updated: December 13, 2022

MCI is a form of cognitive decline where changes are serious enough to be noticed by the affected individual and their family members, but not severe enough to interfere with normal activities of daily living.

Mild Cognitive Impairment (MCI) falls under theBrain HealthandHealthy Aging & Longevitycategories.

What is mild cognitive impairment?

Mild cognitive impairment (MCI) describes a condition where people have poorer memory and thinking skills compared to other people their age but with minimal effects on typical daily tasks. This is sometimes caused by reversible factors like medication side effects, alcohol, poor sleep, and head injuries. But mild cognitive impairment is also the earliest detectable sign of the progressive cognitive decline associated with forms of dementia, including Alzheimer’s disease. Therefore, it is an important condition to detect to prevent the cognitive impairments from becoming sufficient to impair a person’s independence and ability to perform typical daily tasks.[1][2][3]

What are the main signs and symptoms of mild cognitive impairment?

People with mild cognitive impairment may lose things with increasing regularity, find it hard to make decisions and judgments, or notice increasing difficulty with language and remembering appointments and recent events. These symptoms are often also noticed by their friends and family. People with such symptoms should ask their doctor to test for signs that help identify the cause. This is important because some causes of mild cognitive impairment are unrelated to dementia and are treatable.[3][4][2]

The signs of mild cognitive impairment include impaired memory, poor task completion, impaired nerve reflexes, and problems with movement, coordination, and balance.[3][4][2]

How is mild cognitive impairment diagnosed?

The factors that can cause poor memory and thinking skills but are unrelated to dementia (e.g., medications, alcohol, poor sleep, and head injuries) are first ruled out with a medical history. The subsequent diagnosis of mild cognitive impairment involves several steps. Cognitive, neurological, and physical function tests are used to confirm poor memory and thinking skills and to identify problems with movement, coordination, and balance. Additional diagnostic tests may also be used to identify possible causes. For example, brain imaging tests like magnetic resonance imaging (MRI) or positron emission tomography (PET) can detect abnormalities in brain structure, while biochemical tests can detect abnormalities in tau and beta-amyloid protein levels in the cerebrospinal fluid (CSF).[3][4][2][5]

What are some of the main medical treatments for mild cognitive impairment?

The reversible causes of mild cognitive impairment (e.g., medication side-effects, alcohol, poor sleep, and head injuries) can often be treated by addressing those factors directly. For mild cognitive impairment associated with dementia (including Alzheimer's disease), there are no current pharmacological treatments.[6][2][5] Instead, strategies are used to help people with mild cognitive impairment improve their cognitive function and maintain independence in performing their typical daily tasks. These strategies include maintaining regular physical and cognitive activities and social interactions.[2][5][7] But more evidence is needed to determine their efficacy for preventing dementia.[2][5][8]

Have any supplements been studied for mild cognitive impairment?

The effects of several supplements have been studied in people with mild cognitive impairment. These include omega-3 fatty acids, probiotics, ginkgo biloba, B vitamins, vitamin C, vitamin D, vitamin E, etc. However, the current evidence does not support the use of any supplement in people with mild cognitive impairment for improving cognitive function or preventing dementia.[9][10][11][12] That said, the current evidence is limited, and more high-quality large-scale randomized controlled trials are needed to make definitive conclusions.

How could diet affect mild cognitive impairment?

Evidence suggests that higher circulating concentrations of methionine cycle metabolites (homocysteine, methionine, and S-Adenosylmethionine) are associated with greater cognitive decline in people with mild cognitive impairment.[13] Since folate and vitamin B12 regulate methionine metabolism and can reduce plasma homocysteine concentrations,[14] it is possible that their intake may influence cognitive decline. However, while lower folate and B12 concentrations are associated with poorer cognitive function,[15][16][17] current evidence does not show that dietary folate or vitamin B12 intake prevents or treats mild cognitive impairment.[18][9][10]

Other cohort studies show that consuming a mediterranean diet[19][20] and a higher dietary intake of omega-3 fatty acids[21] are associated with a lower risk of mild cognitive impairment. Long-duration randomized controlled trials are needed to prove the causality of these associations.

Are there any other treatments for mild cognitive impairment?

While all types of exercise improve cognitive function in people with mild cognitive impairment[22][23], resistance exercise appears most likely to prevent further cognitive decline.[24] However, the efficacy of exercise in reducing the risk of dementia is currently unclear.[25][26]

Transcranial direct current stimulation (electrically stimulating specific brain regions) can improve memory and cognitive skills in people with mild cognitive impairment.[27][28][29] However, larger and higher-quality randomized controlled trials are needed to determine whether it can prevent or delay cognitive decline.

Computer or app-based cognitive training may also improve cognitive function in people with mild cognitive impairment. But, the current evidence is equivocal and higher-quality studies are needed.[30][31]

Recently, drugs that reduce brain beta-amyloid accumulation (lecanemab, aducanumab, etc) have improved some aspects of cognitive function in people with early-stage Alzheimer's disease.[32][33][34] Other drugs (memantine, donepezil, etc) are also sometimes used to treat symptoms in people with dementia.[35][36] However, the safety and efficacy of these drugs have yet to be tested in people with mild cognitive impairment.

What causes mild cognitive impairment?

The causes of mild cognitive impairment can include the side effects of medications, alcohol, sleep deprivation, head injuries, and some neurological/psychiatric disorders. But mild cognitive impairment is also found in the early stages of neurodegenerative diseases like forms of dementia, including Alzheimer’s disease.[1][2][3]

The exact cause of mild cognitive impairment associated with dementia and Alzheimer’s disease is unknown, but the risk factors include advanced age and diabetes.[2][37] A family history of dementia or Alzheimer's disease also increases risk, suggesting that inherited genetic traits play a role. For example, people with the APOE-ε4 variant in the gene coding apolipoprotein E have a greater risk of developing mild cognitive impairment.[38]

Supplements Demystified: Get Our Unbiased, Evidence-Based Guide

Looking for a Supplement guide?

Our Supplement Guides give you unbiased research-based recommendations that you can immediately apply to improve your health. Mild Cognitive Impairment (MCI) is related to the following Supplement Guides:
Examine Database: Mild Cognitive Impairment (MCI)
What works and what doesn't?

Unlock the full potential of Examine

Get started

Don't miss out on the latest research

  1. ^Knopman DS, Amieva H, Petersen RC, Chételat G, Holtzman DM, Hyman BT, Nixon RA, Jones DTAlzheimer disease.Nat Rev Dis Primers.(2021-May-13)
  2. ^Ronald C Petersen, Oscar Lopez, Melissa J Armstrong, Thomas S D Getchius, Mary Ganguli, David Gloss, Gary S Gronseth, Daniel Marson, Tamara Pringsheim, Gregory S Day, Mark Sager, James Stevens, Alexander Rae-GrantPractice guideline update summary: Mild cognitive impairment: Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of NeurologyNeurology.(2018 Jan 16)
  3. ^Marilyn S Albert, Steven T DeKosky, Dennis Dickson, Bruno Dubois, Howard H Feldman, Nick C Fox, Anthony Gamst, David M Holtzman, William J Jagust, Ronald C Petersen, Peter J Snyder, Maria C Carrillo, Bill Thies, Creighton H PhelpsThe diagnosis of mild cognitive impairment due to Alzheimer's disease: recommendations from the National Institute on Aging-Alzheimer's Association workgroups on diagnostic guidelines for Alzheimer's diseaseAlzheimers Dement.(2011 May)
  4. ^Frederiksen KS, Nielsen TR, Winblad B, Schmidt R, Kramberger MG, Jones RW, Hort J, Grimmer T, Georges J, Frölich L, Engelborghs S, Dubois B, Waldemar GEuropean Academy of Neurology/European Alzheimer's Disease Consortium position statement on diagnostic disclosure, biomarker counseling, and management of patients with mild cognitive impairment.Eur J Neurol.(2021-Jul)
  5. ^Chen YX, Liang N, Li XL, Yang SH, Wang YP, Shi NNDiagnosis and Treatment for Mild Cognitive Impairment: A Systematic Review of Clinical Practice Guidelines and Consensus Statements.Front Neurol.(2021)
  6. ^Fink HA, Jutkowitz E, McCarten JR, Hemmy LS, Butler M, Davila H, Ratner E, Calvert C, Barclay TR, Brasure M, Nelson VA, Kane RLPharmacologic Interventions to Prevent Cognitive Decline, Mild Cognitive Impairment, and Clinical Alzheimer-Type Dementia: A Systematic Review.Ann Intern Med.(2018-Jan-02)
  7. ^Hallam B, Rees J, Petersen I, Cooper C, Avgerinou C, Walters KHow are people with mild cognitive impairment or subjective memory complaints managed in primary care? A systematic review.Fam Pract.(2021-Sep-25)
  8. ^Hafdi M, Hoevenaar-Blom MP, Richard EMulti-domain interventions for the prevention of dementia and cognitive decline.Cochrane Database Syst Rev.(2021-Nov-08)
  9. ^McCleery J, Abraham RP, Denton DA, Rutjes AW, Chong LY, Al-Assaf AS, Griffith DJ, Rafeeq S, Yaman H, Malik MA, Di Nisio M, Martínez G, Vernooij RW, Tabet NVitamin and mineral supplementation for preventing dementia or delaying cognitive decline in people with mild cognitive impairment.Cochrane Database Syst Rev.(2018-11-01)
  10. ^Butler M, Nelson VA, Davila H, Ratner E, Fink HA, Hemmy LS, McCarten JR, Barclay TR, Brasure M, Kane RLOver-the-Counter Supplement Interventions to Prevent Cognitive Decline, Mild Cognitive Impairment, and Clinical Alzheimer-Type Dementia: A Systematic Review.Ann Intern Med.(2018-Jan-02)
  11. ^Xurui Li, Chang Lv, Jinxiao Song, Jianguo LiEffect of Probiotic Supplementation on Cognitive Function and Metabolic Status in Mild Cognitive Impairment and Alzheimer's Disease: A Meta-AnalysisFront Nutr.(2021 Dec 8)
  12. ^Emma Sydenham, Alan D Dangour, Wee-Shiong LimOmega 3 fatty acid for the prevention of cognitive decline and dementiaCochrane Database Syst Rev.(2012 Jun 13)
  13. ^Zhao Y, Dong X, Chen B, Zhang Y, Meng S, Guo F, Guo X, Zhu J, Wang H, Cui H, Li SBlood levels of circulating methionine components in Alzheimer's disease and mild cognitive impairment: A systematic review and meta-analysis.Front Aging Neurosci.(2022)
  14. ^Olaso-Gonzalez G, Inzitari M, Bellelli G, Morandi A, Barcons N, Viña JImpact of supplementation with vitamins B , B , and/or folic acid on the reduction of homocysteine levels in patients with mild cognitive impairment: A systematic review.IUBMB Life.(2022-Jan)
  15. ^Köbe T, Witte AV, Schnelle A, Grittner U, Tesky VA, Pantel J, Schuchardt JP, Hahn A, Bohlken J, Rujescu D, Flöel AVitamin B-12 concentration, memory performance, and hippocampal structure in patients with mild cognitive impairment.Am J Clin Nutr.(2016-Apr)
  16. ^Siuda J, Gorzkowska A, Patalong-Ogiewa M, Krzystanek E, Czech E, Wiechuła B, Garczorz W, Danch A, Jasińska-Myga B, Opala GFrom mild cognitive impairment to Alzheimer's disease - influence of homocysteine, vitamin B12 and folate on cognition over time: results from one-year follow-up.Neurol Neurochir Pol.(2009)
  17. ^Quadri P, Fragiacomo C, Pezzati R, Zanda E, Forloni G, Tettamanti M, Lucca UHomocysteine, folate, and vitamin B-12 in mild cognitive impairment, Alzheimer disease, and vascular dementia.Am J Clin Nutr.(2004-Jul)
  18. ^Malouf R, Grimley Evans JFolic acid with or without vitamin B12 for the prevention and treatment of healthy elderly and demented people.Cochrane Database Syst Rev.(2008-Oct-08)
  19. ^Singh B, Parsaik AK, Mielke MM, Erwin PJ, Knopman DS, Petersen RC, Roberts ROAssociation of mediterranean diet with mild cognitive impairment and Alzheimer's disease: a systematic review and meta-analysis.J Alzheimers Dis.(2014)
  20. ^Natalia García-Casares, Paloma Gallego Fuentes, Miguel Ángel Barbancho, Rosa López-Gigosos, Antonio García-Rodríguez, Mario Gutiérrez-BedmarAlzheimer's Disease, Mild Cognitive Impairment and Mediterranean Diet. A Systematic Review and Dose-Response Meta-AnalysisJ Clin Med.(2021 Oct 10)
  21. ^Run-Ze Zhu, Mei-Qing Chen, Zhi-Wen Zhang, Tian-Yu Wu, Wen-Hong ZhaoDietary fatty acids and risk for Alzheimer's disease, dementia, and mild cognitive impairment: A prospective cohort meta-analysisNutrition.(2021 May 26)
  22. ^Xiang-Lian Zhou, Li-Na Wang, Jie Wang, Ling Zhou, Xin-Hua ShenEffects of exercise interventions for specific cognitive domains in old adults with mild cognitive impairment: A meta-analysis and subgroup analysis of randomized controlled trialsMedicine (Baltimore).(2020 Jul 31)
  23. ^Zhou Y, Li LDExercise training for cognitive and physical function in patients with mild cognitive impairment: A PRISMA-compliant systematic review and meta-analysis.Medicine (Baltimore).(2022-Aug-26)
  24. ^Xiuxiu Huang, Xiaoyan Zhao, Bei Li, Ying Cai, Shifang Zhang, Qiaoqin Wan, Fang YuComparative efficacy of various exercise interventions on cognitive function in patients with mild cognitive impairment or dementia: A systematic review and network meta-analysisJ Sport Health Sci.(2021 May 16)
  25. ^de Souto Barreto P, Demougeot L, Vellas B, Rolland YExercise Training for Preventing Dementia, Mild Cognitive Impairment, and Clinically Meaningful Cognitive Decline: A Systematic Review and Meta-analysis.J Gerontol A Biol Sci Med Sci.(2018-Oct-08)
  26. ^Michelle Brasure, Priyanka Desai, Heather Davila, Victoria A Nelson, Collin Calvert, Eric Jutkowitz, Mary Butler, Howard A Fink, Edward Ratner, Laura S Hemmy, J Riley McCarten, Terry R Barclay, Robert L KanePhysical Activity Interventions in Preventing Cognitive Decline and Alzheimer-Type Dementia: A Systematic ReviewAnn Intern Med.(2018 Jan 2)
  27. ^Jiang L, Cui H, Zhang C, Cao X, Gu N, Zhu Y, Wang J, Yang Z, Li CRepetitive Transcranial Magnetic Stimulation for Improving Cognitive Function in Patients With Mild Cognitive Impairment: A Systematic Review.Front Aging Neurosci.(2020)
  28. ^Chen J, Wang Z, Chen Q, Fu Y, Zheng KTranscranial Direct Current Stimulation Enhances Cognitive Function in Patients with Mild Cognitive Impairment and Early/Mid Alzheimer's Disease: A Systematic Review and Meta-Analysis.Brain Sci.(2022-Apr-27)
  29. ^Xie Y, Li Y, Nie L, Zhang W, Ke Z, Ku YCognitive Enhancement of Repetitive Transcranial Magnetic Stimulation in Patients With Mild Cognitive Impairment and Early Alzheimer's Disease: A Systematic Review and Meta-Analysis.Front Cell Dev Biol.(2021)
  30. ^Butler M, McCreedy E, Nelson VA, Desai P, Ratner E, Fink HA, Hemmy LS, McCarten JR, Barclay TR, Brasure M, Davila H, Kane RLDoes Cognitive Training Prevent Cognitive Decline?: A Systematic Review.Ann Intern Med.(2018-Jan-02)
  31. ^Gates NJ, Vernooij RW, Di Nisio M, Karim S, March E, Martínez G, Rutjes AWComputerised cognitive training for preventing dementia in people with mild cognitive impairment.Cochrane Database Syst Rev.(2019-Mar-13)
  32. ^Swanson CJ, Zhang Y, Dhadda S, Wang J, Kaplow J, Lai RYK, Lannfelt L, Bradley H, Rabe M, Koyama A, Reyderman L, Berry DA, Berry S, Gordon R, Kramer LD, Cummings JLA randomized, double-blind, phase 2b proof-of-concept clinical trial in early Alzheimer's disease with lecanemab, an anti-Aβ protofibril antibody.Alzheimers Res Ther.(2021-Apr-17)
  33. ^Budd Haeberlein S, Aisen PS, Barkhof F, Chalkias S, Chen T, Cohen S, Dent G, Hansson O, Harrison K, von Hehn C, Iwatsubo T, Mallinckrodt C, Mummery CJ, Muralidharan KK, Nestorov I, Nisenbaum L, Rajagovindan R, Skordos L, Tian Y, van Dyck CH, Vellas B, Wu S, Zhu Y, Sandrock ATwo Randomized Phase 3 Studies of Aducanumab in Early Alzheimer's Disease.J Prev Alzheimers Dis.(2022)
  34. ^Avgerinos KI, Ferrucci L, Kapogiannis DEffects of monoclonal antibodies against amyloid-β on clinical and biomarker outcomes and adverse event risks: A systematic review and meta-analysis of phase III RCTs in Alzheimer's disease.Ageing Res Rev.(2021-Jul)
  35. ^Birks JS, Harvey RJDonepezil for dementia due to Alzheimer's disease.Cochrane Database Syst Rev.(2018-Jun-18)
  36. ^McShane R, Westby MJ, Roberts E, Minakaran N, Schneider L, Farrimond LE, Maayan N, Ware J, Debarros JMemantine for dementia.Cochrane Database Syst Rev.(2019-Mar-20)
  37. ^You Y, Liu Z, Chen Y, Xu Y, Qin J, Guo S, Huang J, Tao JThe prevalence of mild cognitive impairment in type 2 diabetes mellitus patients: a systematic review and meta-analysis.Acta Diabetol.(2021-Jun)
  38. ^Jiang Y, He T, Deng W, Sun PAssociation between apolipoprotein E gene polymorphism and mild cognitive impairment: a meta-analysis.Clin Interv Aging.(2017)
Examine Database References
  1. Blood Pressure - Newhouse P, Kellar K, Aisen P, White H, Wesnes K, Coderre E, Pfaff A, Wilkins H, Howard D, Levin EDNicotine treatment of mild cognitive impairment: a 6-month double-blind pilot clinical trialNeurology.(2012 Jan 10)
  2. Depression Symptoms - Krikorian R, Eliassen JC, Boespflug EL, Nash TA, Shidler MDImproved cognitive-cerebral function in older adults with chromium supplementationNutr Neurosci.(2010 Jun)
  3. Depression Symptoms - Krikorian R, Nash TA, Shidler MD, Shukitt-Hale B, Joseph JAConcord grape juice supplementation improves memory function in older adults with mild cognitive impairmentBr J Nutr.(2010 Mar)
  4. Memory - Schreiber S, Kampf-Sherf O, Gorfine M, Kelly D, Oppenheim Y, Lerer BAn open trial of plant-source derived phosphatydilserine for treatment of age-related cognitive declineIsr J Psychiatry Relat Sci.(2000)
  5. Memory - McBean L, O'Reilly SDiet quality interventions to prevent neurocognitive decline: a systematic review and meta-analysis.Eur J Clin Nutr.(2022-Aug)
  6. Memory - Marx W, Kelly JT, Marshall S, Cutajar J, Annois B, Pipingas A, Tierney A, Itsiopoulos CEffect of resveratrol supplementation on cognitive performance and mood in adults: a systematic literature review and meta-analysis of randomized controlled trials.Nutr Rev.(2018-Jun-01)
  7. Cognition - Park SK, Jung IC, Lee WK, Lee YS, Park HK, Go HJ, Kim K, Lim NK, Hong JT, Ly SY, Rho SSA combination of green tea extract and l-theanine improves memory and attention in subjects with mild cognitive impairment: a double-blind placebo-controlled studyJ Med Food.(2011 Apr)
  8. Cognition - Key-Chung Park, Hui Jin, Renhua Zheng, Sehyun Kim, Seung-Eun Lee, Bo-Hyung Kim, Sung-Vin YimCognition enhancing effect of panax ginseng in Korean volunteers with mild cognitive impairment: a randomized, double-blind, placebo-controlled clinical trialTransl Clin Pharmacol.(2019 Sep)
  9. Testosterone - Yamada S, Akishita M, Fukai S, Ogawa S, Yamaguchi K, Matsuyama J, Kozaki K, Toba K, Ouchi YEffects of dehydroepiandrosterone supplementation on cognitive function and activities of daily living in older women with mild to moderate cognitive impairmentGeriatr Gerontol Int.(2010 Oct)
  10. Cognitive Decline - Mori K, Inatomi S, Ouchi K, Azumi Y, Tuchida TImproving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double-blind placebo-controlled clinical trialPhytother Res.(2009 Mar)
  11. Cognitive Decline - Waegemans T, Wilsher CR, Danniau A, Ferris SH, Kurz A, Winblad BClinical efficacy of piracetam in cognitive impairment: a meta-analysisDement Geriatr Cogn Disord.(2002)
  12. Alzheimer's Disease Symptoms - Sudesh Prabhakar, Venugopalan Y Vishnu, Manish Modi, Manju Mohanty, Anchal Sharma, Bikas Medhi, B R Mittal, Niranjan Khandelwal, Manoj K Goyal, Vivek Lal, Rajesh Singla, Avinash Kansal, Ajit AvasthiEfficacy of Bacopa Monnieri (Brahmi) and Donepezil in Alzheimer's Disease and Mild Cognitive Impairment: A Randomized Double-Blind Parallel Phase 2b StudyAnn Indian Acad Neurol.(Nov-Dec 2020)
  13. Cerebral Trauma Rehabilitation - Neznamov GG, Teleshova ESComparative studies of Noopept and piracetam in the treatment of patients with mild cognitive disorders in organic brain diseases of vascular and traumatic originNeurosci Behav Physiol.(2009 Mar)
  14. Alzheimer's Disease Risk - Petersen RC, Thomas RG, Grundman M, Bennett D, Doody R, Ferris S, Galasko D, Jin S, Kaye J, Levey A, Pfeiffer E, Sano M, van Dyck CH, Thal LJ, Alzheimer's Disease Cooperative Study GroupVitamin E and donepezil for the treatment of mild cognitive impairmentN Engl J Med.(2005 Jun 9)