Research analysis: Measuring the impact of Dry January
Despite a substantial increase in participation in the one-month challenge to go ‘alcohol free’, a study published in Drug and Alcohol Dependence found no corresponding reduction in alcohol consumption across England. Natalie Davies takes a look at the research, and asks what the implications are for Dry January, which now reportedly attracts over 100,000 participants each year.
Dry January is an annual campaign from Alcohol Change UK encouraging people to take a month-long break from alcohol. After eating and often drinking to excess over Christmas and the New Year, January has become associated with taking stock of one’s health and breaking up with unhealthy habits.
When Dry January was launched in 2013, an estimated 4,000 people took part. By 2018, that figure had grown to 40,000, and has continued to rise. Approximately 80,000 signed up in 2019, over 100,000 people participated in 2020, and 130,000 people in 2021. A study conducted by Philippa Case and colleagues investigated whether this growth in participation in Dry January has been associated with reduced alcohol consumption in England. As this study used data from 2015 to 2018 the focus is on the 40,000 from 2018 and it does not include those later, higher, figures for participation.
There are many ways to measure the impact of Dry January, but alcohol consumption across England is probably the most useful way to understand whether Dry January could reduce population-level alcohol-related harm. However, as explored below, the focus on consumption alone may also lead to a limited appraisal of Dry January’s value as an intervention.
‘No impact on alcohol consumption in England’
The headline of the study was that Dry January made no discernible impact on population-level alcohol consumption between 2015 and 2018. There was no significant difference in average weekly alcohol consumption between January and non-January months. There was also no significant difference in average weekly alcohol consumption between 2015 and 2018 as participation in Dry January increased.
Original paper: Has the increased participation in the national campaign ‘Dry January’ been associated with cutting down alcohol consumption in England? By Philippa Case and colleagues. Published in Drug and Alcohol Dependence (2021).
These findings indicate that Dry January might not be an effective ‘public health intervention’ – in other words, something that could protect or improve the health, well-being and safety of the entire population. Yet, it might be premature or even unfair to expect it to take on this role. In the last year of the study, an estimated 40,000 people signed up to participate in Dry January via the Alcohol Change UK app and daily emails. This represented a ten-fold increase in the number of participants from 2013 and a considerable growth in awareness of and engagement with Dry January. However, 40,000 is still a very small proportion of the general population.
The total population of England in mid-2018 was estimated to be 55.9 million, of whom 35.0 million were ‘working age’ (aged 16 to 64 years) and 10.2 million were aged over 65. NHS Digital, report that 21% of the adult population regularly drink at levels that increase their risk of ill health. If we assume that the total adult population in 2018 was roughly 45.2 million, the proportion of the population who might have stood to benefit from an alcohol intervention was roughly 9.5 million – meaning that around 0.4% of those who could benefit from Dry January, participated in it.
So, did it help ‘at-risk’ drinkers?
Among ‘at-risk’ drinkers in the study – people scoring five or more on the AUDIT-C screening questionnaire – there were significantly greater odds that a ‘detox’ (such as Dry January) motivated recent attempts to reduce alcohol consumption in January compared with non-January months. The authors could not attribute these quit attempts directly to Dry January, but their data did suggest that this group of people were more motivated (but not necessarily more able) to curb alcohol consumption in January than in other months of the year.
An article on the Alcohol Change UK website cautions that “Dry January isn’t suitable for people at the highest risk of severe harm as a result of alcohol”; it is not intended to be a replacement for treatment. It may, however, be relevant to the broader category of people at risk of alcohol-related harm due to patterns of heavy or frequent drinking. Articulating the appeal of Dry January, the charity says:
“A month without alcohol such as Dry January teaches people that they don’t *need* alcohol for anything they thought they needed it for. They learn how to relax, socialise, unwind, destress and treat themselves without a drink. That realisation is a powerful thing. It means that for the rest of the year having a drink can be a choice – not a default.”
Conversely, Dry January (and other similar campaigns such as Dryathlon and Go Sober for October) might be less appealing to, and potentially have less of an impact on, the portion of the drinking population that does not have this relationship with alcohol.
The appeal of, and rationale for, Dry January
A 2020 study of 4,232 adults who participated in Dry January published in Psychology & Health reported that participants saved money (63%), experienced improved sleep (56%), had more energy (52%), and had better health (50%). Furthermore, they found that participation in the challenge was associated with significant increases in well-being and positive self-beliefs.
Due to the design of this study, the authors could not say that any of these positive changes were caused by Dry January. The study does, however, enable a closer reading of the potential benefits of Dry January, which may be missed with a study that looks at the whole population.
Research has also pointed to the potential physiological benefits of a short period of abstinence from alcohol. For example, among people drinking above national guidelines (over 14 units per week at the time or writing), one study found that a one-month break from drinking was associated with improvements in insulin resistance, blood pressure, and body weight.
If sustained over a longer period of time, such improvements may help to protect people against chronic lifestyle-related health conditions such as diabetes and heart disease. However, the concern or criticism with an intervention such as Dry January is that any positive effects may be short-lived if participants return to their earlier drinking levels.
It is possible, however, that Dry January contributes to a broader cultural change through encouraging conversations around alcohol. And, it is possible that through this cultural shift, rather than by changing the drinking patterns of individual participants, Dry January has the potential to make a population-level impact.
Writing in the featured study, the authors themselves noted:
“…It is possible that the campaign (and other similar campaigns) may have had a broader systems effect by changing culture and affecting long-term and overall consumption, which we have not been able to evaluate here. Future research might explore how these initiatives have impacted alcohol reduction activities more broadly via increased acceptability of abstinence or might take a complex systems perspective (1 2) to explore how the broader system in which campaigns such as Dry January take place may interact with any changes driven by such campaigns.”
Dry January is still a relatively new type of intervention, and it is certainly worth keeping an eye on the literature that emerges over the next few years to better get a grasp on its ability to reduce alcohol-related harm both directly and indirectly.
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