Researchers have identified the effects of long-term alcohol consumption on the brain.
We are aware of the negative health implications of alcohol, such as experiencing hangovers and overworking our liver.
Even moderate alcohol consumption can significantly elevate the risk of developing dementia.
A study conducted in Spain on the post-mortem brains of individuals who had been alcohol-dependent for an average of 35 years has highlighted the extent of the damage it might inflict.
The National Institute on Alcohol Abuse and Alcoholism defines Alcohol Use Disorder (AUD) as ‘an impaired ability to stop or control alcohol use despite adverse social, occupational, or health consequences’.
This research, funded by the Spanish Ministry of Health and published in the Addiction journal, analyzed the brains of 18 individuals with AUD.
Brain tissue samples were obtained from the New South Wales Tissue Resource Centre in Australia, from individuals with chronic AUD who did not use other illicit drugs.
Professor María Salud García-Gutiérrez, the study’s lead author, noted, “This approach provides a much clearer picture of how alcohol alone reshapes gene expression in brain regions central to addiction.”
The research focused on the endocannabinoid system, which plays a role in regulating mood, pleasure, stress, memory, and motivation.
In comparison to those without alcohol addiction, individuals with prolonged alcohol use exhibited significant genetic changes that increase susceptibility to addiction.
The CB1 receptor, which is linked to craving and relapse, was found to be elevated in critical decision-making and reward areas, enhancing the likelihood of addictive behavior being reinforced.
Conversely, CB2, which aids in brain protection and reduces inflammation, was reduced by half, implying the brain may be less capable of defending against alcohol-induced damage.
Additional changes included GPR55, which increased in the decision-making area but decreased in the reward center – a phenomenon not previously observed in humans with alcohol addiction.
Similarly, the FAAH enzyme showed contrasting shifts in these areas, potentially disrupting the levels of a ‘feel-good’ neurotransmitter.
The cumulative effect of these alterations suggests that alcohol may rewire brain signaling, thereby increasing cravings, impairing control, and affecting mood and stress responses.
Jorge Manzanares, the senior author of the study and a professor at The Miguel Hernández University, emphasized, “Alcohol use disorder is one of the leading causes of disease and death worldwide, yet despite its enormous social and health impact, available treatment options remain limited.
“Understanding what changes in the brain after decades of alcohol consumption is essential for developing more effective therapies.”
The American Medical Association advises a daily limit of two drinks for men, defining heavy drinking as consuming five or more drinks in one day or 15 or more drinks in a week.
For women, it is recommended to keep drinking to one per day.