Previous studies suggest that cardiovascular changes, such as reduced heart function and arterial endothelial dysfunction, can occur after scuba diving. The artery's inner layer, known as the endothelium, is comprised of specialized endothelial cells that have several vital functions, including reaction to mechanical forces such as blood pressure and blood flow. Changes in endothelial function have been shown to occur after scuba diving. Now research reports that taking antioxidants (including vitamins C and E) before a dive can help reduce endothelial dysfunction.
The placebo-controlled study, published in The Journal of Physiology, investigated the effects of vitamins C and E supplementation on arterial endothelial function, pulmonary artery pressure (PAP) and heart function after scuba diving. Researchers at the University of Split School of Medicine in Croatia and the Norwegian University of Science and Technology administered either a placebo or 2 grams of vitamin C and 400 international units vitamin E to seven experienced divers two hours before they dived. In a control dive, the seven divers performed an initial scuba dive. In another trial, the divers were given the placebo or vitamins before two successive dives. Ultrasound ventricular volumes and function and pulmonary and brachial artery function were obtained from the participants before and after the dives.
The researchers found that the control dive resulted in heart function changes and reduced endothelial function. Findings also revealed that the vitamin group experienced reduced endothelial dysfunction after diving. However, heart functions and PAP were not affected by vitamin treatment. The heart function changes remained for up to three days.
"Acute antioxidants attenuated arterial endothelial dysfunction after diving, while reduction in heart and pulmonary artery function were unchanged," the study authors write. "Cardiovascular changes after diving are not fully reversed up to 3 days after a dive, suggesting longer lasting negative effects."
REFERENCES:
1. Obad A et al. The effects of acute oral antioxidants on diving-induced alterations in human cardiovascular function. J Physiol 2007 Feb; 578(3):859-870.
Posted by Elaine Gavalas on March 11, 2007 04:12 PM
