Alcohol has been part of the human diet for centuries. However, its excessive consumption can lead to a number of health problems, especially liver damage. What is the biochemical basis of these health problems?
Alcohol cannot be excreted and must be metabolized primarily by the liver. This metabolism occurs in two ways.
Alcohol consumption leads to an accumulation of NADH. This high concentration of NADH inhibits gluconeogenesis by preventing the oxidation of lactate to pyruvate. In fact, the high concentration of NADH causes the reverse reaction to predominate and lactate to accumulate. The consequences can be hypoglycemia and lactic acidosis.
Biochemistry. 5th edition, Section 30.5 Ethanol Alters Energy Metabolism in the Liver
Found at Alkohol adé (german)