Research from Taiwan has shown that chronic drinking can disrupt our biological clock.
Circadian rhythms, the 24-hour cycle that our bodies use as an internal clock, establish our wake/sleep cycle. Research has shown that acute (extremely heavy) or chronic (two or more drinks a day) alcohol consumption causes circadian disturbances that affect sleep, mood, and other daily biological rhythms, including body temperature, blood pressure, and hormone secretion. Many genes involved in this process have been identified and mapped.
Lowered mRNA from these genes is a sign of lowered gene activity and lowered protein production, which is likely related to the sleep and mood disturbances seen in alcohol-dependent people.
The Taiwanese researchers showed that people who had been diagnosed as alcohol dependent were producing much lower amounts of messenger RNA (mRNA) from these genes. Messenger RNA is used as a blueprint from which genes manufacture proteins. Lowered mRNA from these genes is a sign of lowered gene activity and lowered protein production, which is likely related to the sleep and mood disturbances seen in alcohol dependent people.
The researchers examined blood samples from 22 male patients who had been diagnosed as alcohol dependent and were undergoing alcohol withdrawal treatment. These blood samples were compared to those of 12 healthy control subjects.In addition to the differences seen in circadian gene mRNA, the researchers also found that after one week of alc
ohol withdrawal, there were only "very limited restorations of discrete circadian gene expressions." In other words, mRNA levels did not return to normal within a week. The researchers suggest that this may be an indication of long-term damage, though one week simply may not be a long enough period to establish this.
The results of the study will be published in the November 2010 issue of Alcoholism: Clinical & Experimental Research. An advance version of the article was published online by the journal on August 24, 2010.