Alcohol Metabolism 201: Liver Disease
Although we were able to lay a pretty solid foundation in our understanding of alcohol metabolism with the post Alcohol Metabolism 101: An Introduction, it’s time to take a moment to advance that knowledge by discussing how heavy alcohol consumption can result in liver dysfunction and disease.
Previously we learned that alcohol, or ethanol, goes through a couple molecular conversions within the body to minimize the damage caused by its consumption and to ease the process of elimination. However, in predisposed individuals and heavy drinkers, the rate at which the body is able to execute a couple of these conversions is altered in such a way that it increases the liver’s exposure to acetaldehyde, a toxin that impairs the liver’s ability to process and absorb nutrients, which is why malnutrition is a tremendous concern for alcoholics.
What we didn’t touch upon are the specifics of how chronic, heavy alcohol consumption can contribute to the development of diseases like fatty liver, hepatitis and cirrhosis. I know, I know. The physical consequences of excessive alcohol consumption are fairly significant, but there is a progression to our discussion. I promise.
However, before we jump into the fun stuff, I feel it is important to remind my readers again that this may get a little technical so please be patient with me as we walk through the finer points of the process. It’ll be worth it. Trust me.
Helper Enzymes Aiding Disease
When alcohol enters the liver it interacts with the enzyme alcohol dehydrogenase, which contains the “helper” coenzyme NAD+, and is converted the acetaldehyde. In addition to acetaldehyde, the conversion of ethanol oxidizes NAD+, which means it picks up a negatively charged electron and attracts an atom of hydrogen to generate an NADH molecule, a reducing agent that is used in the production of cellular energy, ATP.
NADHs role in the production ATP means that alcohol contributes to energy production and therefore contains Calories, approximately 7 per gram.
This is all well and good, but when alcohol is consumed in excess NADH accumulates beyond the body’s useful capacity and contributes to the production of fatty acids in the liver, which results in the development of fatty deposits and…drum roll, please…fatty liver disease. These fatty deposits, as mentioned, can interfere with the breakdown and absorption of food nutrients by the liver, which can result in severe nutrient deficiency and malnutrition. However, the “good” news is that fatty liver disease can be reversed with abstinence and does not necessarily predispose an individual to the more advanced forms of liver disease.
From Bad to Worse
The next phase of alcohol induced liver disease is hepatitis, which is a consequence of the free radical production that occurs during alcohol metabolism, which induces inflammation and destroys the liver’s ability to function in filtering toxins from the blood, regulating cholesterol levels in the blood and helping to fight infection and disease.
Cirrhosis, fatty liver disease is the worst way, is the result of chronic inflammation and is characterized by the replacement of liver with excessive amounts of scar tissue, which begins with an impairment in the liver’s ability to function and ends with organ failure and death.
Unfortunately, unlike the first phase of fatty liver disease, hepatitis and cirrhosis are chronic condition that generally cannot be cured. However, the damage can be halted and symptoms can be managed with abstinence, medication, and dietary modification.
At this point we know that the heavy consumption of alcohol can interfere with nutrient absorption and may lead to the development of fatty liver disease. Next in our series on alcohol metabolism, we will try and dig a little deeper into the neurological damage caused by alcoholism and how it may contribute to severe mood and behavioral disorders. Finally, once we have discussed all the physical consequences of alcoholism, we will attempt to wrap our heads around the emotional and spiritual effects of chronic consumption.
Until next time, my friends.
Image courtesy of 123RF and Sebastian Kaulitzki