There are two phases of liver detoxification. In the first phase, harmful substances like medication, alcohol and certain food ingredients, are converted into less harmful substances by a group of enzymes known as Cytochrome P450 complex. This happens through a cascade reaction.
The second phase involves conjugation, in which harmful substances bind to other substances such as amino acids like glycine and cysteine. This binding process makes the complex water soluble, allowing it to leave the body through urination.
Liver function naturally decreases with age and harmful substances are not broken down as quickly. The use of medications can further decrease liver function, as all substances are broken down by the same enzymes. A common sign of liver impairment is a decreased ability to tolerate alcohol.
With aging the liver also gradually alterates in structure and function and the liver cells are subject to various changes. Next to that, liver volume and blood flow of the liver decrease as we get older.