Adding to this site’s database of combat sports safety studies, a recent study was published in the Scandinavian Journal of Medicine and Science in Sports addressing whether BJJ athletes, who are subjected to repeated strangulation, sustain impaired cognitive function or reduced arterial blood flow from the practice.
In the study, titled Elevated cerebral perfusion and preserved cognition in elite Brazilian Jiu-Jitsu athletes; evidence for neuroprotection, the authors compared 11 elite BJJ athletes against a control group of eleven non BJJ fitness practitioners. They performed psychometric testing to measure cognitive functioning between the groups and also measured carotid and vertebral arterial blood flow.
The results were that the BJJ athletes did not have cognitive impairment compared to the control group. Arterial blood flow was also not compromised and in fact was a bit stronger in the BJJ athletes compared to the control group leaving the authors to speculate that the repeated strangulation or other BJJ specific training pre-conditioned the BJJ athletes for better carotid and vertebral arterial blood blow.
The full abstract reads as follows:
Brazilian Jiu Jitsu (BJJ) is a popular martial art that exposes participants to recurrent intermittent asphyxiation due to controlled application of neck chokes. To what extent the sport impacts the regulation of cerebral blood flow (CBF) and cognition has not been examined. This study compared eleven elite Brazilian Jiu Jitsu athletes (aged 30 ± 8 y) who trained 12 ± 6 hours/week for 8 ± 4 years against eleven cardiorespiratory fitness (CRF)- and age-matched controls. Internal carotid (ICA) and vertebral (VA) artery blood flow was measured via duplex ultrasound to determine global cerebral blood flow (gCBF). Mild cognitive impairment and sub-domains of memory, attention/concentration/visual motor co-ordination and executive function were determined by psychometric testing. There was no evidence of mild cognitive impairment in the athletes and cognitive function was comparable between groups (all P > 0.05). In contrast, resting gCBF was selectively elevated in the athletes (741 ± 186 mL∙min-1 vs. 573 ± 166 mL∙min-1 , P = 0.037) due to combined differences in ICA (+65 mL∙min-1 , P = 0.079) and VA (+19 mL∙min-1 , P = 0.277) flow. In conclusion, the sustained elevation in resting cerebral perfusion provides preliminary evidence for adaptive neuroprotection that is independent of CRF and likely mediated by choke-induced cerebral preconditioning and/or lifelong exposure to BJJ-specific high-intensity interval training.