Alcohol depresses the production of antidiuretic hormone (ADH), which helps keep you hydrated. Dehydration can lead to electrolyte imbalances (characterized by nausea, dizziness and diarrhea) and headaches. •BREASTS
As little as one alcoholic drink a day can increase the risk of breast cancer, according to a 2009 study in the Journal of the National Cancer Institute. Researchers believe alcohol boosts risk of breast cancer by increasing estrogen levels, a known risk factor for breast cancer. Other theories: alcohol reduces the liver’s ability to clear cell-damaging toxins and depletes the body of cancer-protective antioxidants, such as folate and vitamin C. •STOMACH
Alcohol causes stomach cells to produce excessive amounts of gastric acid, which can irritate the stomach. •PANCREAS
Heavy alcohol use is the most common cause of pancreatitis, an inflammation of the pancreas and a major risk factor for pancreatic cancer. •LIVER
Drinking excessively causes the liver to accumulate fat (fatty liver) and become inflamed (hepatitis). It also leads to cirrhosis, a condition in which liver cells are so damaged they can’t regenerate, and liver failure. Take note: having as few as 3 drinks at once can cause liver damage if mixed with certain medications—including acetaminophen and statin drugs used to treat high cholesterol. If you take any prescription or over-the-counter drugs, ask your doctor or pharmacist whether it’s safe to consume alcohol. •BRAIN
Moderate alcohol consumption may ward off dementia and Alzheimer’s disease. As we age, brain cells die, leading to gaps that slow nerve transmission within the brain and between the brain and the rest of the body. Moderate drinking appears to somehow prevent these “potholes.” (Scientists aren’t sure why.) •In high doses, alcohol kills brain cells,...