Experts pour cold water on global alcohol study

Leading scientists have questioned the results of the world’s first study which reports report alcohol risk by geographical region, age, sex, and year.

The study, which was published in The Lancet, found young people face higher health risks from alcohol consumption than older adults.

It went so far to say that those under 40 should not drink alcohol. As such it suggests that global alcohol consumption recommendations should be based on age and location, with the strictest guidelines targeted toward males between ages 15 and 39, who are at the greatest risk of harmful alcohol consumption worldwide.

The research also indicates that people aged 40 and older without underlying health conditions may see some benefits from small alcohol consumption (between one and two standard drinks per day, including a reduced risk in cardiovascular disease, stroke, and diabetes.

Using estimates of alcohol use in 204 countries, researchers calculated that 1.34 billion people consumed harmful amounts in 2020. In every region, the largest segment of the population drinking unsafe amounts of alcohol were males aged 15–39 and for this age group, drinking alcohol does not provide any health benefits and presents many health risks, with 60% of alcohol-related injuries occurring among people in this age group, including motor vehicle accidents, suicides, and homicides.

“Our message is simple: young people should not drink, but older people may benefit from drinking small amounts. While it may not be realistic to think young adults will abstain from drinking, we do think it’s important to communicate the latest evidence so that everyone can make informed decisions about their health,” says senior author Dr. Emmanuela Gakidou, professor of Health Metrics Sciences at the Institute for Health Metrics and Evaluation (IHME) at the University of Washington’s School of Medicine.

The report was welcomed by leading UK scientists. Prof Kevin McConway, Emeritus Professor of Applied Statistics, The Open University, said there needed to vbe care taken in undestandig what the results mean for individual nations.

“Because of the variation between regions, we do need to take some care in interpreting the figures given in the press release in the UK context, or indeed the context of other specific countries. For instance, the press release says that “For individuals over 65 years in 2020, the risks of health loss from alcohol consumption were reached after consuming a little more than three standard drinks per day.” In the terms used in the research paper, the global average NDE (Non-drinker equivalence) was a bit over three of the standard drinks used in this research per day. But that’s a global average, and the figures vary by region. For the Western Europe region, which includes the UK, the NDE daily level seems to be slightly less. (I can’t give exact figures for the over 65s taken together, since they are not given in the paper, but the numbers for narrower age groups are in Figure 3 in the paper.). But for some other regions, notably Central Asia and Eastern Europe, the NDEs for older people are considerably higher than the global averages.

“Another thing to be careful of in interpreting the numbers in the paper and the press release, is that the ‘standard drink’, referred to in this research, is bigger than a UK standard alcohol unit. The standard drink in this research is 10 grams of pure alcohol (ethanol). A UK alcohol unit is defined in volume terms (10ml of pure alcohol), and corresponds to 8 grams of pure alcohol. So a standard drink’ in the terms of this research is 1.25 UK units.”

He added “ It is true that the way that risk varies with alcohol consumption is different at different ages, and it’s also true that more individuals in young age groups are drinking more than the non-drinker equivalent than for older age groups. But the personal risk seems not to be higher at younger ages. This new research does not give figures for the number of deaths attributable to alcohol consumption at different ages, but the global overall picture is not hugely different from what was in the 2018 report. There, globally, it was estimated that there were (in 2016) about 150,000 deaths of people aged 15-29 attributable to alcohol, compared to about 900,000 deaths of people aged 60-74. Overall, the risk from alcohol is considerably higher for the older age group, but the way the risk varies with alcohol consumption is different at different ages.

Dr Colin Angus, Senior Research Fellow, Sheffield Alcohol Research Group, University of Sheffield, said there were concerns over the report’s conclusions:

“The idea behind this paper is sound – estimating how the relationship between alcohol consumption and risk varies between countries depending on their demographic composition, patterns of alcohol consumption and the prevalence of a wide range of alcohol-related health conditions is a valuable research goal and the analysis itself appears to be well-conducted,” he explained. “However there are a number of serious problems in the way the authors have interpreted their results. The most significant issue is in the headline interpretation that younger age groups should have lower drinking guidelines, which is not supported in any way by the study itself. The analyses presented in this study focus only on relative risk within age groups, but say nothing whatsoever about absolute risk. Younger people are, on average, much less likely to become ill or die “from any cause” than their older counterparts. Assessing how we should set drinking guidelines or prioritise interventions to minimise the total harm of alcohol requires an assessment of absolute, not relative risk. The GBD’s own figures suggest that there are over 14 times as many alcohol-attributable deaths in the UK among 70-74 year-olds than 20-24 year olds, which rather contradicts the assertion in this new study that we should focus on the drinking of younger age groups. There may be valid reasons to target younger drinkers for public health interventions, but those arguments are not presented in this study.”

Dr Tony Rao, Visiting Clinical Research Fellow, Institute of Psychiatry, Psychology and Neuroscience, King’s College London (IoPPN), also said the devil was in the detail and that the report needed to be carefully examined.

“Although the press release summarises the main findings of the study, the conclusions quoted by the senior author that ‘older people may benefit from drinking small amounts’ is inaccurate and does not take into account the shortcomings in the way that the data was measured and interpreted,” he said. “This study focussed on cardiovascular disease, which is known to be more common in older people.”

Rao added: “The work does not fit with existing evidence, particularly for alcohol related harm in older people in the UK. The proportion of over-65s in the UK drinking alcohol over the previous 12 months has increased by 11% over the past 30 years – 4 times higher than in Western Europe. For over-55s in England, rates of alcohol related deaths and alcohol specific admissions have risen more sharply than other age group over the past 15 years. As a risk factor for Disability Adjusted Life Years (DALYs) – the measure used in the current study – alcohol had risen most sharply in people aged 55 and over the past 30 years.

“There are major flaws in this study, two of which stand out. Firstly, there are numerous references to the lower risk of cardiovascular disease compared with non-drinkers with small amounts of alcohol consumption. The authors also point out that this disease burden is more common in older populations compared with younger ones – where alcohol-related injuries predominate. It does therefore not compare like with like, where different thresholds for harm may be present for different disorders. The second flaw is the use of relative risk as measure of outcome and interpretation. Relative risk does not give an indication of absolute risk, from which a more precise estimate of how many more people are affected by ill health from drinking can be calculated.”

He concluded: “The elephant in the room with this study is the interpretation of risk based on outcomes for cardiovascular disease – particularly in older people. We know that any purported health benefits from alcohol on the heart and circulation are balanced out by the increased risk from other conditions such as cancer, liver disease and mental disorders such as depression and dementia. The study also fails to consider why using non-drinkers as a comparison group may be misleading. This group also includes those who have stopped drinking from poor health and those who choose not to drink because of poor health.

“If we are to simply draw the conclusion that older people should continue or start drinking small amounts because it protects against diseased affecting heart and circulation – which still remains controversial – other lifestyle changes or the use of drugs targeted at individual cardiovascular disorders seems like a less harmful way of improving health and wellbeing.”