Alcohol and the brain
THURSDAY is Christmas Day and the period leading up to it is usually replete with office parties and similar celebratory social events. Common to all these events is the presence of various social facilitators, including an abundance of alcohol. Alcohol imbibing across our nation is commonplace, but the Christmas season going into the new year is perhaps the peak period where alcohol overindulgence occurs.
Consequently, at this festive time, we all must be “our brother’s keeper”. If we are going out in a group, we should have a designated driver who should consume little or no alcohol, in order to keep us safe. If we are alone and intend to drive home, we should limit our alcohol intake to only one drink for the evening — to keep ourselves and other users of the road safe.
DISASTROUS CONSEQUENCES OF EXCESSIVE ALCOHOL INTAKE
Heavy alcohol use is known to be associated with an increased risk of injury and has both short- and long-term harmful effects. Impaired judgement and an increased risk of motor vehicle accidents, spousal or child abuse, risky sexual behaviour, and serious medical consequences such as liver damage, high blood pressure, and gastrointestinal cancers in the long term, are all along the spectrum of its effects.
Chronic excessive alcohol use can also wreak havoc on the brain, increasing the risk for dementia, stroke and psychosocial impairment.
The US Food and Drug Administration defines moderate alcohol consumption as up to one drink per day for women, and up to two drinks per day for men. One drink is equivalent to five fluid ounces (one wine glass) of 12 per cent alcoholic wine, 12 fluid ounces (one bottle) of regular beer, or 1.5 fluid ounces of distilled spirits.
BENEFITS OF MILD ALCOHOL INTAKE
The relationship between alcohol and health is a complex one. Numerous studies suggest that mild to moderate intake of alcohol is protective against heart disease, perhaps owing to the effects of alcohol itself and the antioxidant compounds contained therein. Red wine reportedly has the greatest heart-protection benefit, and beer, particularly dark beers such as stouts and porters, have so to a lesser degree. Alcohol has this benefit through possessing anti-inflammatory and anti-plaque formation effects, and has been tied to improved cholesterol profiles, improved platelet and clotting function, and increased sensitivity to insulin. All these factors also have significant benefits for nerve function in the brain.
While light to moderate consumption of alcohol has been linked to a lower risk for both ischaemic (lack of blood flow) and haemorrhagic (breaking of blood vessel with bleeding) strokes, heavy consumption is associated with an increased risk for haemorrhagic stroke, and more severe events in which there is a reduction of blood flow in the brain.
IMPAIRED COGNITION AND DEMENTIA
Lower alcohol use has also been associated with a lower risk for dementia, in contrast with heavy alcohol use, which appears to be severely damaging to the brain. A study published in the journal Neurology in January 2014 found that middle-aged men who drink more than 2.5 drinks per day are more likely to undergo a faster decline in cognitive abilities, particularly memory, over a 10-year period. It is also noteworthy that animal studies suggest that fish oil might be protective against alcohol-induced dementia by reducing the degeneration of the nerves caused by heavy alcohol use.
Of particular concern for both doctors as well as the society are the effects of alcohol on the brain of children and adolescents. A study in Sweden published in the medical journal JAMA Internal Medicine last year reported that among nine factors identified as risk factors for young-onset dementia, the greatest cause was alcohol intoxication. These findings were made doubly worse by the publication in the journal Archives of General Psychiatry, which suggested that most cases of alcohol and drug abuse actually begin in adolescence. Drinking alcohol before the age of 14 increased the risk of the child developing alcohol dependence, and contributed to use and abuse behaviours later on in life. Further, MRI findings revealed that children whose mothers drank heavily during pregnancy had a significantly greater decrease in brain plasticity when compared with those whose mothers did not drink alcohol during pregnancy.
ALCOHOL’S PSYCHOSOCIAL IMPACT
Certain populations with mental illness are more likely to abuse alcohol and other drugs, but excessive alcohol use may also contribute to certain psychiatric conditions, with nearly one-third of alcohol abusers suffering from a mental illness. Alcohol is well known to have considerable psychosocial consequences for those who abuse it, including increased risk of legal troubles, social and occupational impairment and domestic abuse, and a higher likelihood of attempting and committing suicide.
Overindulgence can bring about symptoms that mimic a wide range of psychiatric conditions, including mood, anxiety, psychotic, sleep, sexual, delirious, and amnesia disorders. These psychiatric effects are mediated by the action of alcohol on the neuro-transmitter functions within the brain. A study published in the journal Alcoholism in 2012 found that women were more vulnerable to the effects of alcohol on the brain caused by heavy drinking than men were.
ALCOHOL SCREENING
More than 30 years of research has shown that alcohol screening and brief counselling is effective at reducing risky drinking, and so this should be routine. And so while alcohol has complex interactions with both short- and long-term consequences, these may vary with the age and genetic make-up of the drinker. If consumed in moderation, alcohol may benefit the brain, but if done in excess, the psychiatric, neurologic and other medical consequences can quickly outweigh any benefits.
So, as we indulge in this Yuletide season, we should avoid heavy alcohol use to minimise its effects on our brain and general health. We should always remember the maxim touted by the ancient Greeks: ‘Nothing in excess!’
Derrick Aarons MD, PhD is a consultant bioethicist/family physician, a specialist in ethical issues in medicine, the life sciences and research, and is the Ethicist at the Caribbean Public Health Agency — CARPHA. (The bioethical views expressed here are not written on behalf of CARPHA)