While there is almost no doubt that excessive alcohol use is invariably harmful to health and communities, I believe the study cited1 by Dr Ladouceur in his editorial in the October issue2 does not provide enough evidence to counter the mountain of high-quality evidence that suggests drinking alcohol in moderation is overall beneficial for health. Low alcohol consumption does improve all-cause mortality, diabetes, and cardiovascular disease despite it being a known carcinogen in higher doses.3–5
Although the Whitehall II study does appear to show a correlation between moderate alcohol use and changes on neuroimaging, the cognitive decline outcomes were not consistent.1 However, I believe the main flaw with the study was that magnetic resonance imaging was only performed once during the study. This is effectively a snapshot at one moment in these patients’ lives where self-reported alcohol use was described as moderate. The authors admit that the moderate-to-light drinkers in the study could possibly have been heavier drinkers in the past or even at the time of the study. The Rosenthal effect (the idea that being a study participant makes one behave differently because one is being studied) might have decreased self-reported alcohol use. No amount of statistical wizardry can account for these subtleties of human behaviour.
The so-called J-shaped mortality curve has been discussed in the medical literature for decades and, time after time, large-scale prospective cohort studies and meta-analyses have shown that there is mortality protection from low-dose alcohol consumption. It could be argued that if low-dose alcohol were a pharmaceutical drug, such as thrombolytic agents for acute myocardial infarction, it would be considered unethical to perform further studies.4 Like all drugs, there are contraindications and adverse effects but at the right dose and in the right population, some will benefit.
We often ask our patients to adopt a Mediterranean diet but perhaps we should encourage them to adopt the Mediterranean lifestyle, too. As anyone who has visited Italy would know, this includes a healthy relationship with alcohol where it is enjoyed in moderation, something that we in Canada and the United Kingdom need to practise.
Footnotes
Competing interests
None declared
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