Alcohol consumption is a part of many cultures around the globe. Roughly 7% of the world’s inhabitants stay with an alcohol use dysfunction and roughly 3.7% of the world’s inhabitants stay with alcohol dependence (WHO 2024), and it is a rising worldwide downside.
Alcohol is broadly recognised as a threat issue for quite a lot of ailments and is related to mortality and morbidity around the globe. Disproportionately, this impacts youthful individuals (WHO 2024), nonetheless there may be rising proof for the position of alcohol use within the growth of dementia, a illness with a substantial burden on healthcare methods, caring networks and high quality of life in previous age (Alzheimer’s Society 2024). Earlier research have pointed to the elevated threat of dementia in individuals who have the next consumption of alcohol, even when that is rare (Adams, 2018; Crabbe, 2018; Koch et al 2019). The position of alcohol isn’t solely of explicit significance due to its ubiquitous nature in many individuals’s lives, but in addition represents a modifiable risk factor. Subsequently, understanding the position which it performs within the growth of dementia can assist develop methods to handle it.
The paper reviewed right here by Jeon et al (2023) sought to stratify the dangers within the context of how individuals’s ingesting habits modified over the length of the examine and what could be inferred from the adjustments in dementia threat, relative to ingesting habits.
We all know that alcohol is the primary modifiable threat issue for dementia, however how do adjustments in alcohol consumption have an effect on the incidence of dementia?
Strategies
The paper was a large-scale retrospective cohort examine utilizing the Korean Nationwide Well being Insurance coverage Service (NHIS) database and adopted adults aged 40 years and older from 2009 to 2018. Evaluation of the outcomes happened in December 2021. Individuals underwent two well being examinations, one in 2009 and one in 2011, which have been provided as a part of the free biennial cardiovascular well being screening supplied by the NHIS. The ultimate 3,933,382 contributors have been chosen from an unique group of 4,961,817, with exclusion standards of earlier analysis of dementia, most cancers, heart problems, or loss of life inside one 12 months of their second examination. Medical data for contributors that lacked key variables, together with info on alcohol consumption, have been additionally excluded. The first consequence was newly identified dementia: both Alzheimer’s illness, vascular dementia or different kind. The cohort was assessed from one 12 months after the second well being examination, persevering with till dementia analysis, loss of life or the top of the examine in 2018.
Data referring to alcohol consumption was gained through contributors finishing self-reported questionnaires, which documented frequency and amount of alcohol consumed. Whole weekly alcohol consumption was approximated by changing the alcohol content material of drinks to grams of alcohol and multiplied by frequency. Individuals have been then put into certainly one of 4 teams referring to their alcohol consumption – none (0g per day), delicate (<15g per day), average (15-29.9g per day), or heavy (>30g per day) – and additional put into teams referring to the change of their alcohol consumption from 2009 to 2011 (sustained non-drinkers, quitters, reducers, sustainers and increasers).
Outcomes
The paper presents the crude outcomes alongside two fashions which think about more and more extra co-morbidities and present extra nuanced and clinically informative outcomes. The second mannequin supplies the outcomes that are referred to within the paper and exhibits a statistically important sample of delicate alcohol consumption in 2011 being related to a lowered incidence of all-cause dementia, relative to both being a non-drinker or having average alcohol consumption in 2009.
The diploma of biographical details about contributors permits for fascinating patterns to be recognized. For instance, the authors word that in contrast with individuals who continued to drink, individuals who stopped ingesting alcohol tended to be older, feminine, non-smokers, be extra engaged in common train, and have decrease incomes.
Delicate alcohol consumption was related to a lowered incidence of dementia relative to being a non-drinker or having average alcohol consumption.
Conclusions
The authors word {that a} J-shaped (or U-shaped) affiliation between alcohol consumption and threat of all-cause dementia was current of their outcomes, which is a phenomenon that has been famous in earlier analysis (Sabia et al 2018). Though the outcomes are per earlier research, the precise mechanism of how mild-alcohol consumption could be related to a lowered incidence of dementia stays unclear. The examine feedback on hypothesis that there could also be promotion of prosurvival pathways and a discount in neuroinflammation with delicate alcohol consumption, nonetheless the authors additionally word there may be persevering with debate on “quite a few different [negative] outcomes [associated with alcohol consumption]”. There may be dialogue of the “sick quitter” phenomenon, during which an individual stops a hazardous exercise resulting from well being points. On this case, an individual may cease ingesting alcohol resulting from alcohol-related comorbid sickness, however the influence on the particular person’s threat of dementia stays, even after stopping. Given the myriad associations between alcohol use and long-term well being points this appears an inexpensive consideration, and the authors acknowledge this as a possible bias.
The shortage of a transparent cause for the U-shaped incidence of dementia is especially necessary because the direct neurotoxic impact of alcohol is properly described in different analysis and acknowledged by the authors in their very own conclusions. While these outcomes are thought frightening and add additional weight to the details about the affiliation between alcohol and dementia, it isn’t so simple as suggesting that delicate alcohol consumption is inherently protecting in opposition to the chance of dementia or that abstinence will increase the chance.
Individuals might cease consuming alcohol resulting from alcohol-related comorbid sicknesses; nonetheless, their threat of creating dementia might persist.
Strengths and limitations
This paper has two primary strengths; firstly the scale of the inhabitants used and secondly wanting on the influence of adjustments to alcohol consumption, which has not been properly described beforehand. Utilizing the NHIS, the examine authors have been in a position to seize information from practically 4 million individuals, which fits an extended option to minimising the problems of spurious outcomes being amplified (as they may be in smaller research). It’s value noting that a big pattern dimension doesn’t essentially modify an underlying bias, though it’ll result in narrower confidence intervals and consequently a consequence nearer to the inhabitants common. Prior research usually seemed on the influence of a constant degree of alcohol consumption relative to the chance to well being. Getting access to the NHIS and the repeated nature of the well being screenings allowed the authors to take a look at the influence of adjusting alcohol consumption.
The authors concede that contributors have been self-selecting as not everybody would attend a well being screening, and those who did so have been extra prone to be taking higher care of their general well being. Additionally they acknowledge that the consumption of alcohol was self-reported, which leaves the outcomes open to consumption being underestimated. While imperfect, different research point out that quantity-frequency measurements are doubtless to supply dependable measures in population-based surveys (McKenna et al 2018). Additionally they remark that kind (and subsequently presumably, alcohol content material) of drinks weren’t recorded, though earlier research recommend that there should not convincing arguments for one kind of alcohol to be much less dangerous than one other (Mäkelä et al 2011). The authors additionally touch upon the diploma to which genetics might influence the applicability of those outcomes to different ethnic teams, resulting from distinction in alcohol metabolism and the unmeasured cofounder of genetic threat elements such because the APOE genes.
It’s also necessary to notice that this examine was a retrospective cohort examine. This was an inexpensive alternative as the end result measure was comparatively frequent and a considerable amount of details about the cohort members was obtainable to assist with figuring out cofounding elements. Nonetheless, the observational nature of the examine implies that correlation solely, relatively than causality, could be inferred from the outcomes.
Alcohol consumption was self-reported on this examine; it’s attainable that folks underreported the degrees of alcohol they have been consuming.
Implications for apply
Alcohol consumption has been recognised as a modifiable threat issue for various ailments for a few years (Koch et al 2019) and given the degrees of consumption around the globe, stays a subject of curiosity for a lot of nations. It’s also a subject reported on within the mainstream press each as a profit and a hurt (Guardian 2022). This paper helps add extra info across the matter of alcohol consumption as a threat issue for dementia. This info might be utilized in help of discussions with older adults relating to the dangers of average alcohol use and the advantages of discount, when full cessation could also be undesired or unachievable. It might, nonetheless, additional confuse the understanding of the dangers of alcohol consumption by most people, relying on how it’s reported within the mainstream press.
Cautious interpretation of those outcomes is required to make sure that apply is greatest knowledgeable.
Assertion of pursuits
Dr Kube-Clare has no undisclosed pursuits.
Hyperlinks
Major paper
Jeon KH, Han Okay, Jeong SM, Park J, Yoo JE, Yoo J, Lee J, Kim S, Shin DW. Changes in Alcohol Consumption and Risk of Dementia in a Nationwide Cohort in South Korea. JAMA Netw Open. 2023 Feb 1;6(2):e2254771. doi: 10.1001/jamanetworkopen.2022.54771. PMID: 36745453.
Different references
Adams, S. Reasonable and heavy alcohol consumption: what influence on later life mind and cognition? Alcohol consumption: what impact on later life brain and cognition? The Psychological Elf, April 2018.
Alzheimer’s Society, The economic impact of dementia. (Accessed November 2024)
Crabbe, M. Alcohol is the number one modifiable risk factor for dementia. The Psychological Elf, April 2018.
Guardian 14th July 2022 “Alcohol is never good for people under 40, global study finds”
Koch M, Fitzpatrick AL, Rapp SR, et al. Alcohol Consumption and Risk of Dementia and Cognitive Decline Among Older Adults With or Without Mild Cognitive Impairment. JAMA Netw Open. 2019;2(9):e1910319. doi:10.1001/jamanetworkopen.2019.10319
McKenna, H., Treanor, C., O’Reilly, D. et al. Evaluation of the psychometric properties of self-reported measures of alcohol consumption: a COSMIN systematic review. Subst Abuse Deal with Prev Coverage 13, 6 (2018). https://doi.org/10.1186/s13011-018-0143-8
Mäkelä P, Hellman M, Kerr W, Room R. A bottle of beer, a glass of wine or a shot of whiskey? Can the rate of alcohol-induced harm be affected by altering the population’s beverage choices? Contemp Drug Probl. 2011 Winter;38(4):599-619. doi: 10.1177/009145091103800408. PMID: 24431477; PMCID: PMC3888958.
Sabia S, Fayosse A, Dumurgier J, Dugravot A, Akbaraly T, Britton A et al. Alcohol consumption and risk of dementia: 23 year follow-up of Whitehall II cohort study BMJ 2018; 362 :k2927 doi:10.1136/bmj.k2927
WHO 2024, Alcohol Fact Sheet, (accessed November 2024)
