Of all the possible pitfalls* which can affect bungee jumpers, a compromised immune system might not be the first to spring to mind. But spring it did to the minds of David J van Westerloo, Goda Choi, Ester C Löwenberg, Jasper Truijen, Alex F de Vos, Erik Endert, Joost C M Meijers, Lu Zhou, Manuel PFL Pereira, Karla CS Queiroz, Sander H Diks, Marcel Levi, Maikel P Peppelenbosch, and Tom van der Poll, who have collectively examined, by experiment, the effects that a jump might have.
20 volunteers (naive to bungee jumping) were exposed to a bungee jump from an altitude of 60m, at the foundation teaching hospital Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands.
“The study site was located at the hospital grounds, where a crane was placed. Bungee jumps took place from an altitude of 60 m, under supervision and guidance from an experienced commercial bungee jump crew. On the morning of the study day, an intravenous access catheter was placed in the cubital vein.“
Half had been previously treated with a three day course of propranolol (a beta blocker) and the control group were not. Subsequent blood analyses showed that :
“Plasma catecholamine and cortisol levels increased significantly during jumping, which was accompanied by significantly reduced ex vivo inducibility of proinflammatory cytokines as well as activation of coagulation and vascular endothelium. Kinome profiles obtained from the peripheral blood leukocyte fraction contained a strong noncanonical glucocorticoid receptor signal transduction signature after jumping. In apparent agreement, jumping down regulated Lck/Fyn and cellular innate immune effector function (phagocytosis). Pretreatment of volunteers with propranolol abolished the effects of jumping on coagulation and endothelial activation but left the inhibitory effects on innate immune function intact. Taken together, these results indicate that bungee jumping leads to a catecholamine-independent immune suppressive phenotype and implicate noncanonical glucocorticoid receptor signal transduction as a major pathway linking human stress to impaired functioning of the human innate immune system.”
see: ‘Acute Stress Elicited by Bungee Jumping Suppresses Human Innate Immunity’ in Molecular Medicine, December 2010.
Note that the volunteers actually did the jumps, but many showed obvious signs of stress before jumping. Therefore further studies might be needed to determine whether the immune system effects were caused by mental strain or by the physical stresses of the jump (or both).
Coming Soon : Medical benefits from bungee cord injuries.