In Defence of Liberty

Driven by data; ridden with liberty.

On Alcohol Guidance

alcohol-guidance-kimerydavis

The new guidance for drinking alcohol has been issued. (Edited: kimerydavis)

New guidelines for alcohol consumption state that men and women do not consume more than 14 units of alcohol each week, as recommended by the Chief Medical Officer [1]. This differs from the previous guidance issued in 1995, through a reduction in the upper threshold, the equal amounts between the sexes and the conclusion that “there is no justification for drinking for health reasons” [2].

The epidemiological evidence of alcohol effects on morbidity and mortality were analysed in a report commissioned by Public Health England, and conducted by the Sheffield Alcohol Research Group, based at the University of Sheffield. The Sheffield reports considers two methods for determining acceptable thresholds of risk from drinking alcohol: Canada and Australia.

The Canadian method was based around research from epidemiology which suggested that low levels of drinking provided a ‘protective effect’, as the mortality rates from light consumers of alcohol was lower than for teetotallers, that is, not drinking. The threshold chosen was when the relative risk from drinking became equal to those who abstained from alcohol. The Australian method was to discover the level of drinking, if undertaken by the entire population, would mean 1% of annual deaths would be attributable to alcohol. The Canadian method considered relative risks, whereas the Australian method was centred around absolute risks.

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This is the implied guidances on the basis of different approaches. (Source: DoH)

Whilst the two methods result in similar results for women, they differ widely for men. It should be noted that the evidence for distinct mortality rates for men and women from drinking alcohol remains crystalline, but the Department of Health has chosen the simplicity of a single number: 14 units per week. This gender equality is unusual in Europe.

alcohol-guidance-bbc

Health officials typically set different standards for men and women. (Source: BBC/DoH)

“Low risk”

This guidance is termed as the “low risk threshold”, rather than ‘safe’ drinking, because:

15. The analysis of the evidence of levels of alcohol consumption for a number of different health harms reviewed by the group, including the evidence on cancer risks, make it apparent that there is no level of regular drinking that is completely without risks to health in the long term.

The idea that small amounts of alcohol might be beneficial was dismissed as an “old wives’ tale” by Sally Davies, the Chief Medical Officer [3].

A 1994 paper in the British Medical Journal [4], led by Sir Richard Doll, found that for British male doctors “small amounts of alcohol are associated with a lower risk of death from ischaemic heart disease, and from several other causes”. Alcohol dosing and mortality became the subject of much research, with a 2006 meta-analysis of 34 prospective studies [5] then robustly concluding “low levels of alcohol intake (1-2 drinks per day for women and 2-4 drinks per day for men) are inversely associated with total mortality in both men and women”.

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This is from a 2006 meta-analysis. (Source: JAMA Internal Medicine)

There are diseases for which abstinence from alcohol is the best policy to minimise risks, such as various types of cancer [6].

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The relative risk rises along with alcohol consumption. (Source: NIH)

The Canadian Model

However, the all-cause mortality risk being lower for light drinkers than for teetotallers was confirmed by the Sheffield report. For men drinking an average of seven units per week, over three to seven days, a small, overall protective effect is observed. For women, drinking seven units per week, on average, induces a similar effect.

alcohol-guidance

From their own estimations, the Sheffield report low consumption of alcohol provides an “overall protective effect”. (Source: DoH)

There is no activity in this world that is completely safe, or totally divorced from risks. The question is: compared to what? The Canadian model assumes the point of comparison for harms arising from drinking alcohol is against never drinking alcohol.

Consuming alcohol, for some diseases like ischaemic heart disease, induces reduced mortality at low and moderate levels of drinking, before it becomes indisputably harmful at higher levels. For other diseases, the minimum risk of death is from those who do not drink at all. Overall, these effects mean that people who moderately drink alcohol actually have a reduced mortality rate, when compared against those who abstain from alcohol.

Ideally, medical advice should be focused on ensuring heavy drinkers taper themselves down to moderate consumption.

References

[1] Department of Health, 2016. Alcohol Guidelines Review — Report from the Guidelines development group to the UK Chief Medical Officers. Available from: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/489797/CMO_Alcohol_Report.pdf [Accessed: 13th January 2016]

[2] BBC, 2016. New alcohol guidelines: what you need to know. Available from: http://www.bbc.co.uk/news/uk-35252650 [Accessed: 13th January 2016]

[3] Watson, L., 2016. Drink tea instead of wine, health chief says. Telegraph. Available from: http://www.telegraph.co.uk/news/health/news/12088748/A-glass-of-red-wine-a-day-being-good-for-you-is-just-an-old-wives-tale-health-chief-says.html [Accessed: 13th January 2016]

[4] Doll, R., Peto, R., Hall, E., Wheatley, K., and Gray, R., 1994. Mortality in relation to consumption of alcohol: 13 years’ observations on male British doctors. BMJ. Available from: http://www.bmj.com/content/309/6959/911 [Accessed: 13th January 2016]

[5] Di Castelnuovo, A., Constanzo, S., Bagnardi, V., Donati, M., Iacoviello, L., and de Gaetano, G., 2006. Alcohol Dosing and Total Mortality in Men and Women. JAMA Internal Medicine. Available from: http://archinte.jamanetwork.com/article.aspx?articleid=769554 [Accessed: 13th January 2016]

[6] Bagnardi, V., Blangiardo, M., La Vecchia, C., and Carrao, G., Year Unknown. Alcohol Consumption and the Risk of Cancer: A Meta-Analysis. Available from: http://pubs.niaaa.nih.gov/publications/arh25-4/263-270.htm [Accessed: 13th January 2016]

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This entry was posted on January 15, 2016 by in National Politics and tagged , , .
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