Sunday, 12 October 2014

Caffeinated and Decaffeinated Coffee Promote Liver Health

Researchers have discovered that drinking three or more cups of coffee a day benefits the liver. Both caffeinated and decaffeinated coffee produce the same benefits, so people who must avoid or limit caffeine are still in luck.

The research team was led by Dr. Qian Xiao from the National Cancer Institute. The researchers studied the results of the US National Health and Nutrition Examination Survey, or NHANES. The survey took place from 1999 to 2010 and involved over 27,000 people. During the survey, participants described their coffee consumption over a twenty-four hour period and also had blood tests to measure the level of four important liver enzymes in their blood. The enzymes are strongly linked to liver health.

Coffee has important health benefits.
Public domain image
The researchers discovered that people who drank three or more cups of either caffeinated or decaffeinated coffee in a day had a lower level of all four liver enzymes than people who didn't drink coffee. Although the blood normally contains a small quantity of the enzymes, a high level suggests that the liver is inflamed or injured. When liver cells are damaged, their enzymes can escape into the blood. Coffee seems to protect liver cells from damage.

The four enzymes that were measured were:

  • alanine transaminase, or ALT (also known as alanine aminotransferase)
  • aspartate transaminase, or AST (also known as aspartate aminotransferase)
  • alkaline phosphatase, or ALP
  • gamma-glutamyl transpeptidase, or GGT (also known as gamma-glutamyl transferase)
Caffeinated coffee has been shown to have other health benefits, including reducing the chance of liver cancer and type 2 diabetes and improving the movement ability of people with Parkinson's disease. Coffee does have some disadvantages, though. In some people it causes jitters or heart palpitations. It can also stain teeth, increase urine production and act as a laxative. Still, its potential health benefits are very tempting. It would be great if some of these benefits extended to decaffeinated coffee. Happily, according to the latest research, maintaining liver health is one benefit of drinking coffee without caffeine.