An interesting seminar was hosted by the Portman Group on ‘The effects of heavy drinking on brain function, cognition and psychomotor performance’ in May.
Professor Theodora Duka, an experimental psychologist reported on her studies involving 500 18 - 32 year old students and staff from Sussex , UK. Her research defined bingeing as actual drunkeness followed by sober periods.
According to Duka, the frontal lobe part of the brain is not fully developed until your early twenties, making age of onset of drinking and important factor. Her studies found that binge drinkers showed less strategic thinking than moderate drinkers in carrying out mental tasks and that females are affected more severley than males. Thuka also cited a study by Randall et al 2004 which found that moderate drinkers demonstrated better planning than non-drinkers.
Townshend and Duka 2005 conclude that although it is not yet proved, whilst comparing moderate drinkers verus binge drinkers that females are more susceptible to cognitive damage and that the younger the age of onset of binge drinking the greater the effect. The study however only looked at short term cognitive effects of drinking through students carrying out a series of mental tasks.
Dr Adele McKinney of the University of Belfast looked at the immedite effects of hangover on 48 students at 9 am, 11 am and 1pm respectively and compared their motor performance against those who had abstained from drinking for 24 hours.The students drank a mean of 11 units between 10pm and 2pm and had not eaten during that period (until breakfast at 8pm, allowing no caffeine). Her studies found that ‘free recall’ recovers by 11 am in drinkers but their motor performance remains poorer. Those with hangover were particularly distracted by stress - white noise was used in this incidence.
Professor Joris Verster of Utrecht University looked at the affect of over 21 units of 12g of alcohol on 46 -50 year olds. 10% of the Dutch popultion (14% men and 6% women)drink at these levels. Former studies by Verster have proved the effect of increasing BAC levels on driving through anaylsis of the ‘swerve factor’ or deviation from a straight road.
Verster demonstrated how heavy and dependent drinkers have smaller brains, less grey focal matter and larger ventricals than moderate, light or non drinkers. Again his studies showed that moderate drinkers (5-20 units a week) perform best in cognitive recognition than heavy drinkers or abstainers.
Verster also looked at the genetic contribution of having an alcoholic relative on cognitive function by use of ECG, MRI scans, behavioural and cognitive tests. His results showed there was increased synchronisation of meta and gamma bands with heavy drinking (which are involved with memory and learning). Functional brain activity is impaired by heavy drinking although no differences were found through the behavioural tasks. This may have been because they were too easy.
Interestingly, amongst males consuming up to 20 units a week (defined as moderate drinking), there was a positive increase in white brain matter, although no change was seen in females consuming up to 15 drinks a week. Conversely there is a decrease in grey focal matter as drinking increases. Verster cannot account for gender differences, it could be due to metabolic differences, lower mean alcohol consumption, different patterns of drinking and or beverage choice.
Verset concluded that there is no doubt that persistent heavy drinking irrespective of genetic input is linked to cognitive impairment in older drinkers.