New research indicates that “when” you work could be a factor in alcoholic liver disease.
Alcohol is a known liver toxin. Thus, it is no surprise that alcoholics are at high risk of developing liver disease. Although the risk is significant, not every alcoholic succumbs to this fate. In the quest to isolate what factors might increase the odds of alcoholics developing liver disease, researchers have uncovered a likely catalyst – circadian rhythm disruption.
About Circadian Rhythms
Following a 24-hour cycle, circadian rhythms are physical, mental and behavioral changes that respond to light and darkness in the environment. Circadian rhythms are found in most living things, including humans, animals, plants and microbes. There are patterns of brain wave activity, hormone production, cell regeneration and other biological activities linked to a 24-hour cycle.
- The circadian clock in humans is located mainly in the suprachiasmatic nucleus, which is a group of cells located in the brain’s hypothalamus.
- Circadian rhythms are important in determining human sleeping patterns.
- Analogous to the body’s master clock, the suprachiasmatic nucleus controls the production of melatonin, a hormone that causes sleepiness.
- Since the suprachiasmatic nucleus is located just above the eyes’ optic nerves, these cells relay information about lightness and darkness.
- At night, darkness signals the suprachiasmatic nucleus to make more melatonin for creating and maintaining drowsiness.
Circadian Rhythm Sleep Disorder
Usually associated with a disruption in sleep, circadian rhythm disorders can be caused by many factors such as:
- Shift work
- Time zone changes or jet lag
- Routine changes
Shift work is a common cause of a circadian rhythm sleep disorder. Affecting people who frequently rotate shifts or work at night, schedules of these people defy the body’s natural circadian rhythm. Consisting of a constant or recurrent pattern of sleep interruption that results in insomnia or excessive sleepiness, shift work sleep disorders are common in people who work non-traditional hours, usually between 10:00 p.m. and 6:00 a.m.
A type of liver disease, alcoholic hepatitis is an acute form of alcohol-induced liver injury that occurs with the consumption of a large quantity of alcohol over a prolonged period of time. Alcoholic hepatitis can progress quickly from an asymptomatic problem to severe liver damage and can even cause death.
The prevalence of alcoholic liver disease is influenced by many variables, including genetic and environmental factors. Although the risk of liver disease increases with the quantity and duration of alcohol intake, excessive alcohol use does not automatically result in alcoholic liver disease. Experts estimate that only about 30 percent of severe alcoholics develop liver disease; a statistic that has doctors baffled at which factors influence this risk most.
Circadian Rhythms and Alcoholism
A research team from Northwestern University and Rush University Medical Center has tested a hypothesis explaining that circadian rhythm sleep disruption may push alcoholics over the edge to alcoholic liver disease. Although their testing was not performed on human subjects, this research team studied animals that had their circadian clocks disrupted. According to senior author of the study Fred W. Turek, “Circadian disruption appears to be a previously unrecognized risk factor underlying the susceptibility to or development of alcoholic liver disease.”
The researchers found the combination of circadian rhythm disruption and alcohol to be a destructive double hit that can lead to alcoholic liver disease. Working the ‘graveyard shift’ may be a financially rewarding experience, but it also poses a unique hazard for alcoholics. Armed with this information, shift workers should be aware that nighttime work schedules are not recommended for anyone who drinks excessive amounts of alcohol – because it could be the missing circumstance needed for developing alcoholic liver disease.
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