Dark chocolate reduces endothelial dysfunction after successive breath-hold dives in cool water.
OBJECTIVE
The aim of this study is to observe the effects of dark chocolate on endothelial function after a series of successive apnea dives in non-thermoneutral water.


METHODS
Twenty breath-hold divers were divided into two groups: a control group (8 males and 2 females) and a chocolate group (9 males and 1 female). The control group was asked to perform a series of dives to 20 m adding up to 20 min in the quiet diving pool of Conflans-Ste-Honorine (Paris, France), water temperature was 27 °C. The chocolate group performed the dives 1 h after ingestion of 30 g of dark chocolate. Flow-mediated dilatation (FMD), digital photoplethysmography, nitric oxide (NO), and peroxynitrite ONOO−) levels were measured before and after each series of breath-hold dives.


RESULTS
A significant decrease in FMD was observed in the control group after the dives (95.28 ± 2.9 % of pre-dive values, p < 0.001) while it was increased in the chocolate group (104.1 ± 2.9 % of pre-dive values, p < 0.01). A decrease in the NO level was observed in the control group (86.76 ± 15.57 %, p < 0.05) whereas no difference was shown in the chocolate group (98.44 ± 31.86 %, p > 0.05). No differences in digital photoplethysmography and peroxynitrites were observed between before and after the dives.


CONCLUSIONS
Antioxidants contained in dark chocolate scavenge free radicals produced during breath-hold diving. Ingestion of 30 g of dark chocolate 1 h before the dive can thus prevent endothelial dysfunction which can be observed after a series of breath-hold dives.
Sigrid
S
Theunissen
Julie
J
Schumacker
François
F
Guerrero
Frauke
F
Tillmans
Antoine
A
Boutros
Kate
K
Lambrechts
Aleksandra
A
Mazur
Massimo
M
Pieri
Peter
P
Germonpré
Costantino
C
Balestra
D000328:Adult; D000975:Antioxidants / Q000032:analysis / Q000494:pharmacology; D062485:Breath Holding; D002099:Cacao / Q000737:chemistry*; D002182:Candy; D016022:Case-Control Studies; D003080:Cold Temperature; D004242:Diving; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000097:blood; D030421:Peroxynitrous Acid / Q000097:blood; D059289:Vascular Stiffness / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
D000975:Antioxidants; D030421:Peroxynitrous Acid; D009569:Nitric Oxide