Boxing is bad for the brain

How dangerous is boxing for the brain?

The Heidelberg boxer study finds no clear risks from amateur sports - publication in the "American Journal of Neuroradiology"

Boxing may be less dangerous for the brain than previously feared - at least for amateurs. However, conclusive statements on the risk are not yet possible. It remains to be seen whether professional boxers like Muhammad Ali contracted their future brain disease - in this case Parkinson's disease at the age of 40 - with a high probability while doing sports. The all-clear can only be given when extensive studies involving both amateur and professional boxers have clarified the risks of boxing for the brain.

This is the conclusion reached by the "Heidelberg Boxer Study", which used high-resolution magnetic resonance imaging (MRI) to search for tiny brain changes in the brains of amateur boxers and a non-boxing comparison group. These are probably the precursors of later severe brain damage such as Parkinson's disease or dementia.

The study by the Neurological University Clinic Heidelberg has now been published in the "American Journal of Neuroradiology". Tiny point hemorrhages were found in three of the 42 boxers, while there were no such changes in the comparison group of 37 non-boxers; however, the difference was not statistically significant. The study was carried out jointly with the boxer group of the Heidelberg Olympic Training Center and the Sports Medicine Department at Heidelberg University Hospital (Medical Director: Professor Dr. Peter Bärtsch).

Tiny bleeding could be a precursor to Parkinson's disease and dementia

When boxing, the head is hit at high speed and with great force. Shear movements can occur between the brain tissues, resulting in tiny bleeding. "Injuries of this kind can be excellently detected with the ultra-modern MRI with a field strength of 3 Tesla, which is available in Heidelberg," explains Professor Dr. Stefan Hähnel, Senior Physician in Charge of the Department of Neuroradiology at the Neurological University Clinic in Heidelberg, who conducted the study with Professor Dr. Uta-Meyding-Lamadé, formerly senior physician at the Neurological University Clinic Heidelberg, now chief physician at the Nord-West-Krankenhaus Frankfurt.

It is not known how often the micro-bleeding occurs in boxers. Ultimately, they could lead to the demise of brain cells and functional failures such as dementia or Parkinson's disease. This hypothesis is supported by some working groups. The three boxers who showed changes typically showed them in the anterior cerebrum, where the shear forces from boxing blows have their main effect.

Follow-up study will compare amateur boxers with professionals

A disadvantage of the "Heidelberg Boxer Study" was the wide range of boxing duration and intensity when practicing amateur sport: The duration varied from 1 to 25 years and the intensity from one to 375 fights with 0 to 12 knockouts. A follow-up study should include boxers who play the sport professionally in order to be able to assess intense stress on the brain. The Heidelberg company is currently looking for a way to finance the study.

Hähnel S, Stippich C, Weber I, Darm H, Schill T, Jost J, Friedmann B, Heiland S, Blatow M, Meyding-Lamadé U: Prevalence of Cerebral Microhemorrhages in Amateur Boxers as detected by 3-Tesla Magnetic Resonance Imaging. Am J Neuroradiol 29 (2): 388-391 (2008)

(The original article can be obtained from the press office of the university hospital
Heidelberg at [email protected])

Further reading:
Blennow K, Popa C, Rasulzada A, et al. There is strong evidence that professional boxing results in chronic brain damage. The more head punches during a boxer's career, the bigger is the risk. Lakartidningen 102 (36): 2468-70, 2472-5 (2005)

Unterharnscheidt F. A neurologist's reflections on boxing. I: Impact mechanics in boxing and injuries other than central nervous system damage. Rev Neurol 23 (121): 661-74 (1995).

Contact Person:
Professor Dr. Stefan Hähnel
Senior physician, Department of Neuroradiology
Radiological University Clinic Heidelberg
Tel .: 06221/56 39 608
Email: [email protected]

Professor Dr. Uta Meyding-Lamadé
Northwest Hospital
Steinbacher Hohl 2 - 26th
60488 Frankfurt am Main
Email: [email protected]

For questions from journalists:
Dr. Annette Tuffs
Press and public relations work at the Heidelberg University Hospital
and the Medical Faculty of the University of Heidelberg
In Neuenheimer Feld 672
69120 Heidelberg
Tel .: 06221/56 45 36
Fax: 06221/56 45 44
Email: annette.tuffs (at)

Dr. Michael Schwarz
Press spokesman for the University of Heidelberg