Light drinking of alcohol, especially of red wine, appears to have modestly beneficial effects on the cardiovascular system, according to some studies. A new study from researchers at the University of Pennsylvania Medical Center, however, shows that heavier consumption of alcohol, far from being helpful, initiates a free-radical mediated process that has been linked to heart disease, stroke, cirrhosis of the liver, and many other disorders.
At levels commonly seen in social drinking, alcohol prompts a sharp increase in corrosive free radical activity in the body, the Penn study demonstrates. Such an increase in oxidant stress could well contribute to the evolution of a wide array of chronic diseases, the scientists say. The experiments also show that the antioxidant vitamin C partially quells the activity of these volatile molecules, potentially limiting the injury to organs and tissues. A report on the findings appears in the September 15 issue of the Journal of Clinical Investigation.
"These findings show that drinking alcohol activates a mechanism that has been implicated in a number of illnesses, including diseases of the liver and the cardiovascular system," says Garret A. FitzGerald, MD, chairman of pharmacology and senior author on the study. "At blood alcohol levels frequently attained in social settings, although above the limit for safe driving, damaging pro-oxidant processes are set in motion."
In healthy volunteers given alcohol in an experimental setting and in abstaining patients being treated for alcohol-induced liver diseases, measures of oxidant stress due to free radicals were significantly elevated.
Ten healthy volunteers were given 0.4, 0.6, and 0.9 g/kg of a 98 percent
solution of grain alcohol, which raised their blood alcohol levels, on average,
to .08, .10, and .13 g/dl respectively. The volunteers experienced, on average,
69, 289, and 345 percent increases respectively in levels of a biochemical
Contact: Franklin Hoke
University of Pennsylvania School of Medicine