A new study challenging the much debated health benefits claimed for moderate drinking has been published in the Lancet, adding to the evidence that positive health outcomes amongst low level drinkers are less likely to be due to a direct effect of alcohol.
The research, indicating no protective effect of moderate consumption against stroke, follows a large scale study published last year indicating there was no overall beneficial effect of moderate drinking on mortality risk when considering all conditions, despite lower levels of cardiovascular disease among those drinking at low levels. It states 'the apparently protective effects of moderate alcohol intake against stroke are largely non-causal', and that alcohol consumption 'uniformly increases blood pressure and stroke risk'.
Previous research has been largely unable to determine to what extent alcohol versus other factors, such as socio-economic status, prior drinking patterns or health conditions, may be explaining observed differences in moderate versus abstaining populations, often known as the j-curve. The latest study however utilised genetic differences found amongst some East Asian populations where a common gene variant leads to people typically drinking significantly less, enabling a more causal interpretation of the link between stroke and alcohol consumption. A systematic review also published in the Lancet last year explored issues with existing research, concluding the level of consumption that minimises health loss is zero.
Based on data from 500,000 Chinese people over 10 years, the latest study found drinking one to two small alcoholic drinks every day (100g /12.5 units per week) increased stroke risk by 10-15% and by 35% if drinking four drinks per day. Prof David Spiegelhalter, Winton professor for the public understanding of risk, at the University of Cambridge, said it was a very 'impressive study' and that 'I have always been reasonably convinced that moderate alcohol consumption was protective for cardiovascular disease, but now I am having my doubts'.
Dr Stephen Burgess, from the University of Cambridge, said the research 'strongly suggests that there is no cardiovascular benefit of light drinking and that risk of stroke increases even with moderate light alcohol consumption', adding that the 'risk of stroke increases proportionally with the amount of alcohol consumed.' However, the study authors identify further questions including remaining uncertainty over the relationship with low consumption and heart attacks. Widespread media reporting of the study appeared fairly responsible - see Guardian, BBC and The Independent reports.
'No safe level' messages - a growing case?
The latest study adds further weight to the evidence that any level of alcohol consumption increases overall risk, and thus any protective or positive effects seen are likely to be explained by other differences in moderate drinking populations, rather than an effect of alcohol itself. As such some groups have increasingly favoured a 'no safe level' over a low risk message, particularly concerning cancer risks. However, not all within the public health community agree, largely owing to the small degree of risk when drinking within the recommended guidelines of 14 units a week, calculated as equivalent to 1% increased risk of dying of an alcohol-related condition over a lifetime.
Debates over communication regarding alcohol-related risks and consumption levels therefore continues, with many arguing that approaches geared towards enabling the public to determine or appraise their own acceptable risk as key. Indeed, important questions remain over the extent to which guideline messages may influence behaviour. Whilst few disagree with the need to promote and enable informed decision-making, how or who should be communicating such messages continues as a high profile alcohol policy issue. Last year Public Health England (PHE) faced criticism for its decision to partner with industry funded Drinkaware for the 'drink free days' campaign.
Cigarettes & alcohol
Also of relevance to risk communication debates, another recent study compared the estimated cancer risk of drinking one bottle of wine a week (10 units) as 'equivalent' to smoking ten cigarettes a week for women or five for men - see BBC news report.
The BMC press release said the study 'aims to draw the public’s attention to the fact that just moderate levels of drinking, e.g. one bottle of wine per week can put people at risk of cancer, particularly breast cancer'. the study states if 1,000 non-smoking men and 1,000 non-smoking women each drank one bottle of wine a week, around 10 extra men and 14 extra women could develop cancer during their lives compared to abstaining.
Dr Theresa Hydes, one of the study's authors, said: 'We must be absolutely clear that this study is not saying that drinking alcohol in moderation is in any way equivalent to smoking. Our finds relate to lifetime risk across the population. At an individual level, cancer risk represented by drinking or smoking will vary and for many individuals, the impact of ten units of alcohol (one bottle of wine) or five to ten cigarettes may be very different.'
Where next for public messaging?
Last month NHS Scotland launched a new 'count 14' campaign to promote awareness of the recommended guidelines, prompting calls for similar efforts to be adopted in England. This coincided with a series of academic responses raised over various issues relating to such policy decisions, including the accumulating evidence that 'consuming less alcohol, either in total or on a per occasion basis, would probably improve health for most drinkers', regardless of how drinkers themselves may respond to such a message. Meanwhile, the absence of any over-arching national alcohol strategy for England leaves the future for these, and many other related issues, somewhat uncertain.
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