Skip to main content
SpringerLink
Log in

Mortality Risk from Neurodegenerative Disease in Sports Associated with Repetitive Head Impacts: Preliminary Findings from a Systematic Review and Meta-Analysis

  • Systematic Review
  • Published:
Sports Medicine Aims and scope Submit manuscript

Abstract

Background

Professional athletes seem to have a lower overall mortality risk than the general population, but controversy exists about whether athletes in sports associated with repetitive head impacts have a higher risk of mortality from neurodegenerative diseases.

Objective

We aimed to determine the risk of mortality from neurodegenerative diseases in sports associated with repeated head impacts compared with the general population or compared with athletes with no such exposure.

Methods

We conducted a systematic review with meta-analysis, systematically searching PubMed, Web of Science, Scopus, and SPORTDiscus (since inception to 14 May 2021) for studies comparing the risk of death from neurodegenerative disease in athletes participating in contact sports in which their heads recurrently receive blows from the bodies of other participants or from a ball versus a control group or dataset representing the general population.

Results

Six moderate- to high-quality retrospective studies including data from 41,699 athletes participating in contact sports (boxing, basketball, ice hockey, American Football and soccer) met all inclusion criteria to be included in the systematic review. Of these, three studies (N = 37,065 male professional soccer players) could be meta-analysed. Despite no differences in the risk of all-cause (p = 0.138), cardiovascular (p = 0.085) and cancer-related mortality (p = 0.136), soccer players presented with a significantly higher mortality risk from motor neuron disease (standard mortality rate 8.43; 95% confidence interval 3.07–23.13; p < 0.001).

Conclusions

Although more research is needed (particularly in other contact sports and with neurodegenerative disease as the cause of death), preliminary evidence suggests that participation in professional soccer might increase the risk of mortality from motor neuron disease compared with the general population. The present findings highlight the need for the design of preventive measures and for adequate neuropsychological monitoring in these athletes.

PROSPERO registration

CRD42020195647.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

References

  1. Garatachea N, Santos-Lozano A, Sanchis-Gomar F, Fiuza-Luces C, Pareja-Galeano H, Emanuele E, et al. Elite athletes live longer than the general population: a meta-analysis. Mayo Clin Proc. 2014;89(9):1195–200.

    Article  Google Scholar 

  2. Antero J, Tanaka H, De Larochelambert Q, Pohar-Perme M, Toussaint JF. Female and male US Olympic athletes live 5 years longer than their general population counterparts: a study of 8124 former US Olympians. Br J Sports Med. 2020;55:206–12.

    Article  Google Scholar 

  3. Santos-Lozano A, Pareja-Galeano H, Sanchis-Gomar F, Quindós-Rubial M, Fiuza-Luces C, Cristi-Montero C, et al. Physical activity and Alzheimer disease: a protective association. Mayo Clin Proc. 2016;91(8):999–1020.

    Article  Google Scholar 

  4. Mez J, Daneshvar DH, Kiernan PT, Abdolmohammadi B, Alvarez VE, Huber BR, et al. Clinicopathological evaluation of chronic traumatic encephalopathy in players of American Football. JAMA. 2017;318(4):360–70.

    Article  Google Scholar 

  5. Kmush BL, Mackowski M, Ehrlich J, Walia B, Owora A, Sanders S. Association of professional football cumulative head impact index scores with all-cause mortality among National Football League players. JAMA Netw Open. 2020;3(5):e204442.

    Article  Google Scholar 

  6. Manley G, Gardner AJ, Schneider KJ, Guskiewicz KM, Bailes J, Cantu RC, et al. A systematic review of potential long-term effects of sport-related concussion. Br J Sports Med. 2017;51(12):969–77.

    Article  Google Scholar 

  7. Moher D, Liberati A, Tetzlaff J, Altman DG, Group P. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. J Clin Epidemiol. 2009;62(10):1006–12.

    Article  Google Scholar 

  8. Stroup DF, Berlin JA, Morton SC, Olkin I, Williamson GD, Rennie D, et al. Meta-analysis of observational studies in epidemiology: a proposal for reporting. Meta-analysis Of Observational Studies in Epidemiology (MOOSE) group. JAMA. 2000;283(15):2008–12.

    Article  CAS  Google Scholar 

  9. Kettunen JA, Kujala UM, Kaprio J, Bäckmand H, Peltonen M, Eriksson JG, et al. All-cause and disease-specific mortality among male, former elite athletes: an average 50-year follow-up. Br J Sports Med. 2015;49(13):893–7.

    Article  Google Scholar 

  10. Taioli E. All causes of mortality in male professional soccer players. Eur J Public Health. 2007;17(6):600–4.

    Article  Google Scholar 

  11. Wells GA, Shea B, O’Connell D, et al. The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomised studies in meta-analyses [cited 2021 May 15]. Available from: http://www.ohri.ca/programs/clinical_epidemiology/oxford.asp.

  12. IntHout J, Ioannidis JP, Borm GF. The Hartung-Knapp-Sidik-Jonkman method for random effects meta-analysis is straightforward and considerably outperforms the standard DerSimonian–Laird method. BMC Med Res Methodol. 2014;14:25.

    Article  Google Scholar 

  13. Bax L, Yu LM, Ikeda N, Tsuruta H, Moons KG. Development and validation of MIX: comprehensive free software for meta-analysis of causal research data. BMC Med Res Methodol. 2006;6:50.

    Article  Google Scholar 

  14. Belli S, Vanacore N. Proportionate mortality of Italian soccer players: is amyotrophic lateral sclerosis an occupational disease? Eur J Epidemiol. 2005;20(3):237–42.

    Article  Google Scholar 

  15. Lehman EJ, Hein MJ, Baron SL, Gersic CM. Neurodegenerative causes of death among retired National Football League players. Neurology. 2012;79(19):1970–4.

    Article  Google Scholar 

  16. Mackay DF, Russell ER, Stewart K, MacLean JA, Pell JP, Stewart W. Neurodegenerative disease mortality among former professional soccer players. N Eng J Med. 2019;381(19):1801–8.

    Article  Google Scholar 

  17. Nguyen VT, Zafonte RD, Chen JT, Kponee-Shovein KZ, Paganoni S, Pascual-Leone A, et al. Mortality among professional American-style Football players and professional American Baseball players. JAMA Netw Open. 2019;2(5):e194223.

    Article  Google Scholar 

  18. Adams JW, Alvarez VE, Mez J, Huber BR, Tripodis Y, Xia W, et al. Lewy body pathology and chronic traumatic encephalopathy associated with contact sports. J Neuropathol Exp Neurol. 2018;77(9):757–68.

    Article  CAS  Google Scholar 

  19. Bieniek KF, Ross OA, Cormier KA, Walton RL, Soto-Ortolaza A, Johnston AE, et al. Chronic traumatic encephalopathy pathology in a neurodegenerative disorders brain bank. Acta Neuropathol. 2015;130(6):877–89.

    Article  CAS  Google Scholar 

  20. Bieniek KF, Blessing MM, Heckman MG, Diehl NN, Serie AM, Paolini MA, et al. Association between contact sports participation and chronic traumatic encephalopathy: a retrospective cohort study. Brain Pathol. 2002;30(1):63–74.

    Article  Google Scholar 

  21. Han TS, Gabe J, Sharma P, Lean MEJ. Life expectancy of white and non-white elite heavyweight boxers. J Racial Ethn Heal Disparities. 2020;7(2):281–9.

    Article  Google Scholar 

  22. Hazrati LN, Tartaglia MC, Diamandis P, Davis KD, Green RE, Wennberg R, et al. Absence of chronic traumatic encephalopathy in retired football players with multiple concussions and neurological symptomatology. Front Hum Neurosci. 2013;24(7):222.

    Google Scholar 

  23. Kucera KL, Yau RK, Register-Mihalik J, Marshall SW, Thomas LC, Wolf S, et al. Traumatic brain and spinal cord fatalities among high school and college football players—United States, 2005–2014. MMWR Morb Mortal Wkly Rep. 2017;65(52):1465–9.

    Article  Google Scholar 

  24. McKee AC, Stein TD, Nowinski CJ, Stern RA, Daneshvar DH, Alvarez VE, et al. The spectrum of disease in chronic traumatic encephalopathy. Brain. 2013;136(Pt-1):43–64.

    Article  Google Scholar 

  25. Venkataramani AS, Gandhavadi M, Jena AB. Association between playing American Football in the National Football League and long-term mortality. JAMA. 2018;319(8):800–6.

    Article  Google Scholar 

  26. McMichael AJ. Standardized mortality ratios and the “healthy worker effect”: scratching beneath the surface. J Occup Med. 1976;18(3):165–8.

    Article  CAS  Google Scholar 

  27. Li CY, Sung FC. A review of the healthy worker effect in occupational epidemiology. Occup Med (Lond). 1999;49(4):225–9.

    Article  CAS  Google Scholar 

  28. Abel EL, Kruger ML. The healthy worker effect in professional football. Res Sports Med. 2006;14(4):239–43.

    Article  Google Scholar 

  29. Ehrlich J, Kmush B, Walia B, Sanders S. Mortality risk factors among National Football League players: an analysis using player career data. F1000Res. 2019;8:2022.

    Article  Google Scholar 

  30. Russell ER, McCabe T, Mackay DF, Stewart K, MacLean JA, Pell JP, et al. Mental health and suicide in former professional soccer players. J Neurol Neurosurg Psychiatry. 2020;91(12):1256–60.

    Article  Google Scholar 

  31. Abel EL, Kruger ML. The healthy worker effect in major league baseball revisited. Res Sports Med. 2006;14(1):83–7.

    Article  Google Scholar 

  32. Teramoto M, Bungum TJ. Mortality and longevity of elite athletes. J Sci Med Sport. 2010;13(4):410–6.

    Article  Google Scholar 

  33. Lemez S, Baker J. Do elite athletes live longer? A systematic review of mortality and longevity in elite athletes. Sports Med Open. 2015;1(1):16.

    Article  Google Scholar 

  34. Fogelholm M, Kaprio J, Sarna S. Healthy lifestyles of former Finnish world class athletes. Med Sci Sports Exerc. 1994;26(2):224–9.

    Article  CAS  Google Scholar 

  35. Eisen G, Turner D. Myth and reality: social mobility of the American Olympic athletes. Int Rev Sociol Sport. 1992;27(2):165–74.

    Article  Google Scholar 

  36. Manning KY, Brooks JS, Dickey JP, Harriss A, Fischer L, Jevremovic T, et al. Longitudinal changes of brain microstructure and function in nonconcussed female rugby players. Neurology. 2020;95(4):e402–12.

    Article  Google Scholar 

  37. Alosco ML, Mez J, Tripodis Y, Kiernan PT, Abdolmohammadi B, Murphy L, et al. Age of first exposure to tackle football and chronic traumatic encephalopathy. Ann Neurol. 2018;83(5):886–901.

    Article  Google Scholar 

  38. Chiò A, Benzi G, Dossena M, Mutani R, Mora G. Severely increased risk of amyotrophic lateral sclerosis among Italian professional football players. Brain. 2005;128(Pt 3):472–6.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. MOVE-IT Research Group, Department of Physical Education, Faculty of Education Sciences, University of Cadiz, Cadiz, Spain

    Javier S. Morales

  2. Physical Activity and Health Laboratory, Instituto de Investigación Sanitaria Hospital ‘12 de Octubre’ (‘imas12’, PaHerg), Madrid, Spain

    Pedro L. Valenzuela, Alejandro Santos-Lozano & Alejandro Lucia

  3. Bioenergy and Motion Analysis Laboratory, National Research Center on Human Evolution (CENIEH), Burgos, Spain

    Gonzalo Saco-Ledo

  4. Fissac-Physiology, Health and Physical Activity, Madrid, Spain

    Adrián Castillo-García

  5. Neurotraumatology and Subarachnoid Hemorrhage Research Unit, Department of Neurosurgery, Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain

    Cristina S. Carabias

  6. Traumatic Brain Injury Laboratory, The Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre-Austin Campus, Heidelberg, VIC, Australia

    Paul McCrory

  7. I+HeALTH, Department of Health Sciences, European University Miguel de Cervantes, Valladolid, Spain

    Alejandro Santos-Lozano

  8. Faculty of Sport Sciences, Universidad Europea de Madrid, Villaviciosa de Odón, 28670, Madrid, Spain

    Alejandro Lucia

Authors
  1. Javier S. Morales
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Pedro L. Valenzuela
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Gonzalo Saco-Ledo
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Adrián Castillo-García
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Cristina S. Carabias
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Paul McCrory
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Alejandro Santos-Lozano
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Alejandro Lucia
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Alejandro Lucia.

Ethics declarations

Funding

Research by the authors was supported by the Universidad de Alcalá (Pedro L. Valenzuela, contract #FPI2016) and the Spanish Ministry of Economy and Competitiveness and Fondos Feder (Alejandro Lucia, grant PI18/00139; and Cristina S. Carabias, contract FI19/00287, grant PI18/01387). No other sources of funding were used to assist in the preparation of this article.

Conflict of interest

Paul McCrory is a co-investigator on competitive grants relating to mild TBI and funded under a Fellowship awarded by the National Health and Medical Research Council of Australia. He has been reimbursed by government, professional scientific bodies, and commercial organizations for discussing or presenting research relating to MTBI and sport-related concussion at meetings, scientific conferences, and symposiums. He does not hold any individual shares in and has not received remuneration from any company related to concussion or brain injury assessment or technology over the past 5 years. Javier Morales, Pedro Valenzuela, Gonzalo Saco-Ledo, Adrián Castillo-García, Cristina Carabias, Paul McCrory, Alejandro Santos-Lozano and Alejandro Lucia have no conflicts of interest relevant to the content of this review.

Availability of data and material

Data are available upon request.

Ethics approval

Not applicable.

Consent

Not applicable.

Author contributions

JSM had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Concept and design: All authors. Acquisition, analysis, or interpretation of data: ACG, GSL, JSM, PLV. Drafting of the manuscript: JSM. Critical revision of the manuscript for important intellectual content: AL, CSC, JSM, PLV, PM. Statistical analysis: AL, ASL, JSM, PLV. Administrative, technical, or material support: ACG, AL, GSL. Supervision: AL, JSM. All authors provided permission for the submission and publication of this version of the review.

Supplementary Information

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Morales, J.S., Valenzuela, P.L., Saco-Ledo, G. et al. Mortality Risk from Neurodegenerative Disease in Sports Associated with Repetitive Head Impacts: Preliminary Findings from a Systematic Review and Meta-Analysis. Sports Med 52, 835–846 (2022). https://doi.org/10.1007/s40279-021-01580-0

Download citation

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s40279-021-01580-0

Search

Navigation