Sir, – "Life expectancy to drop by a year due to alcohol consumption, says OECD" (News, May 20th). Good. Modern medicine adds years to our lives. If that adds a few on, and alcohol takes one off, so what? So what if I don't live to be a hundred and die at 99? The only thing I'll miss out on is a cheque from the President, and anyway, by then inflation will make it worth about €2 in today's money. I won't even be able to buy a pint! – Yours, etc,
PETER SHAUGHNESSY,
Dublin 8.
Sir, – Natalie Grover reports that British researchers have found that even moderate drinking is linked to lower brain grey-matter density ("'No safe amount': All alcohol consumption 'harmful to the brain'", News, May 19th).
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To set this finding in a wider context, the same effect has also been observed in users of many other legal and illegal psychoactive substances including caffeine, which is the most commonly used psychostimulant worldwide, consumed in coffee, tea, energy drinks and minerals.
The interaction of caffeine and sleep on brain grey matter was researched by a team led by Dr Carolin Reichert and Prof Christian Cajochen of the University of Basel. Their study was funded by the Swiss National Science Foundation and the findings were published online in the journal Cerebral Cortex on February 15th, 2021.
Reichert and Cajochen found that regular caffeine intake significantly reduces grey matter volume. However, they also found that after 10 days of caffeine abstinence, grey matter volume significantly rebounds.
Yu-Shiuan Lin, a member of the research team, told Megan Brooks of Medscape Medical News (March 3rd, 2021) that they “don’t have clear evidence . . . indicating any functional consequences of the reduced grey matter” and nor do they know “if such restorable plasticity . . . entails gains or harms”.
When Dr Flavio Frohlich, director of the Carolina Centre for Neurostimulation at the University of North Carolina was asked by Medscape Medical News for a reaction to Reichert’s team’s findings, he noted that grey matter volume “can be quite dynamic”. He also commented that the study’s findings are “of interest for the planning of follow-up studies”.
From that perspective the British team’s findings on alcohol and grey matter may prove less than black and white. Rather, they should be seen as part of an unfolding discourse, the next stage of which may involve the dynamic between psychoactive drugs and brain plasticity. – Yours, etc,
Dr DERMOT STOKES,
Dublin 4.