Alcohol - Low to Moderate

Dozens of observational studies and many meta-analyses and systematic reviews report inconsistent conclusions on whether moderate levels of alcohol consumption prevent or promote cognitive decline. Our search identified:

• Multiple meta-analyses and systematic reviews on observational studies
• 0 randomized controlled trials
• Multiple observational studies

Although many observational studies have examined whether drinking low to moderate amounts of alcohol is associated with a reduced risk of developing Alzheimer’s disease, vascular dementia, or age-related cognitive decline, they reached no consensus [1; 2; 3; 4; 5; 6]. Most of these studies suffer from a number of confounding factors, particularly with respect to the characteristics of the non-drinking comparator population. In general, a large percentage of non-drinkers have a higher baseline risk for dementia due to sex, socioeconomic status, lifestyle factors, education, dietary habits, and/or health status [7]. Wine drinkers, as opposed to beer or spirit drinkers, have been more likely to show reduced dementia risk, which some have attributed to potential cardiovascular effects. However, individuals who regularly have a glass of wine tend to also have high socioeconomic status and engage in other brain healthy behaviors [6]. In the short-term, alcohol is well-known to impair cognitive function, and heavy drinking is an established risk factor for cognitive decline [8]. Recent well-designed studies that track people over time have found that even moderate levels of alcohol consumption, such as one to two drinks per day, is associated with adverse brain changes consistent with accelerated brain aging [9; 10; 11; 12].

APOE4 CARRIERS:

APOE4 has been found to impact a variety of lifestyle-related dementia risk factors. APOE4 carriers who drink high amounts of alcohol appear to be at greater risk for dementia than APOE4 carriers who drink rarely or never [13; 14; 15]. APOE4 carriers may also be at greater risk from the brain health side effects of moderate alcohol consumption than those who do not have the APOE4 variant [16; 17; 18].

For Dementia Patients

There is no evidence that alcohol use can slow the progression of cognitive decline in patients with Alzheimer's disease or dementia. Given that alcohol can acutely impair cognitive function and interacts dangerously with many medications, patients with dementia should probably abstain.

According to the World Health Organization, there is no safe level of alcohol consumption [19]. Heavy drinking is associated with a number of potential side effects including high blood pressure, obesity, stroke, cardiovascular disease, liver disease, certain forms of cancer, and Alzheimer's disease [4; 20; 21]. However, individual susceptibility to the negative effects of alcohol varies across people such that it is not possible to identify a uniformly safe level of consumption. In studies looking at brain changes, drinking the equivalent of two drinks or less per week was not associated with harm [11], and this level is also considered low risk in the 2023 Canadian guidelines [22].

NOTE: This is not a comprehensive safety evaluation or complete list of potentially harmful drug interactions. It is important to discuss safety issues with your physician before taking any new supplement or medication.

The guidelines regarding alcohol consumption vary in different countries. In the United States, moderate alcohol intake is defined as one drink per day for women and two drinks per day for men [23]. These are similar to the guidelines in Europe [24] but exceeds the Canadian recommended guidelines for low-risk consumption of no more than one to two drinks per week [22]. A standard drink in the United states is equivalent to roughly 14 grams of alcohol, which is found in 12 ounces of regular beer (~5% alcohol), 5 ounces of wine (~12% alcohol), and about 1.5 ounces of distilled spirits (~40% alcohol). Since high levels of alcohol are acutely toxic to the brain, the safest way to consume it is in small doses over an extended period of time, such as no more than one glass of wine with dinner consumed over the course of an hour or two.

General information on how to define different types of drinking can be found at the Centers for Disease Control, and the National Institute on Alcohol Abuse and Alcoholism.

Information on alcohol’s effects on the body can be found at the National Institute on Alcohol Abuse and Alcoholism.

Check for drug-alcohol and supplement-alcohol interactions on Drugs.com.

1. Beydoun MA, Beydoun HA, Gamaldo AA et al. (2014) Epidemiologic studies of modifiable factors associated with cognition and dementia: systematic review and meta-analysis. BMC Public Health 14, 643
2. Cao L, Tan L, Wang HF et al. (2015) Dietary Patterns and Risk of Dementia: a Systematic Review and Meta-Analysis of Cohort Studies. Mol Neurobiol.
3. Peters R (2012) Blood pressure, smoking and alcohol use, association with vascular dementia. Experimental gerontology 47, 865-872.
4. Lafortune L, Martin S, Kelly S et al. (2016) Behavioural Risk Factors in Mid-Life Associated with Successful Ageing, Disability, Dementia and Frailty in Later Life: A Rapid Systematic Review. PloS one 11, e0144405.
5. Rehm J, Hasan OSM, Black SE et al. (2019) Alcohol use and dementia: a systematic scoping review. Alzheimer's Research & Therapy 11, 1.
6. Mewton L, Visontay R, Hoy N et al. (2023) The relationship between alcohol use and dementia in adults aged more than 60 years: a combined analysis of prospective, individual-participant data from 15 international studies. Addiction (Abingdon, England) 118, 412-424.
7. Rehm J, Irving H, Ye Y et al. (2008) Are lifetime abstainers the best control group in alcohol epidemiology? On the stability and validity of reported lifetime abstention. American journal of epidemiology 168, 866-871.
8. Livingston G, Huntley J, Sommerlad A et al. (2020) Dementia prevention, intervention, and care: 2020 report of the Lancet Commission. The Lancet 396, 413-446.
9. Sabia S, Fayosse A, Dumurgier J et al. (2018) Alcohol consumption and risk of dementia: 23 year follow-up of Whitehall II cohort study. BMJ 362, k2927.
10. Topiwala A, Allan CL, Valkanova V et al. (2017) Moderate alcohol consumption as risk factor for adverse brain outcomes and cognitive decline: longitudinal cohort study. BMJ 357, j2353.
11. Topiwala A, Ebmeier KP, Maullin-Sapey T et al. (2022) Alcohol consumption and MRI markers of brain structure and function: Cohort study of 25,378 UK Biobank participants. NeuroImage: Clinical 35, 103066.
12. Daviet R, Aydogan G, Jagannathan K et al. (2022) Associations between alcohol consumption and gray and white matter volumes in the UK Biobank. Nature communications 13, 1175
13. Harwood DG, Kalechstein A, Barker WW et al. (2010) The effect of alcohol and tobacco consumption, and apolipoprotein E genotype, on the age of onset in Alzheimer's disease. International journal of geriatric psychiatry 25, 511-518.
14. Bleich S, Wilhelm J, Graesel E et al. (2003) Apolipoprotein E epsilon 4 is associated with hippocampal volume reduction in females with alcoholism. J Neural Transm (Vienna) 110, 401-411.
15. Anttila T, Helkala EL, Viitanen M et al. (2004) Alcohol drinking in middle age and subsequent risk of mild cognitive impairment and dementia in old age: a prospective population based study. BMJ 329, 539.
16. Downer B, Zanjani F, Fardo DW (2014) The relationship between midlife and late life alcohol consumption, APOE e4 and the decline in learning and memory among older adults. Alcohol Alcohol 49, 17-22.
17. Virtaa JJ, Jarvenpaa T, Heikkila K et al. (2010) Midlife alcohol consumption and later risk of cognitive impairment: a twin follow-up study. Journal of Alzheimer's disease : JAD 22, 939-948.
18. Kivipelto M, Rovio S, Ngandu T et al. (2008) Apolipoprotein E epsilon4 magnifies lifestyle risks for dementia: a population-based study. Journal of cellular and molecular medicine 12, 2762-2771.
19. Anderson BO, Berdzuli N, Ilbawi A et al. (2023) Health and cancer risks associated with low levels of alcohol consumption. The Lancet Public Health 8, e6-e7https://doi.org/10.1016/S2468-2667(22)00317-6.
20. Turati F, Galeone C, Rota M et al. (2014) Alcohol and liver cancer: a systematic review and meta-analysis of prospective studies. Ann Oncol 25, 1526-1535.
21. Sayon-Orea C, Martinez-Gonzalez MA, Bes-Rastrollo M (2011) Alcohol consumption and body weight: a systematic review. Nutrition reviews 69, 419-431.
22. Canadian Centre on Substance Use and Addiction (2023) Canada’s Guidance on Alcohol and Health: Final Report.
23. CDC (2022) Dietary Guidelines for Alcohol.
24. European Commission (2022) National low-risk drinking recommendations (or drinking guidelines) and standard units.