There is also emerging evidence “that there are risks even within these levels, especially for certain types of cancer and some forms of cardiovascular disease,” said Marissa Esser, who leads the alcohol program at the Centers for Disease Control and Prevention.
Acetaldehyde both “damages your DNA and prevents your body from repairing the damage,” Esser explained. “Once your DNA is damaged, then a cell can grow out of control and create a cancer tumor.”
Alcohol also creates oxidative stress, another form of DNA damage that can be particularly harmful to the cells that line blood vessels. Oxidative stress can lead to stiffened arteries, resulting in higher blood pressure and coronary artery disease.
Alcohol’s effect on the heart is confusing because some studies have claimed that small amounts of alcohol, particularly red wine, can be beneficial. Past research suggested that alcohol raises HDL, the “good” cholesterol, and that resveratrol, an antioxidant found in grapes (and red wine), has heart-protective properties.