May 16th 2023
Excessive alcohol use can cause damage to the brain which can lead to the development of dementia. To reduce this risk, it is recommended to follow guidelines around safe levels of alcohol consumption or to engage in treatment for alcohol use disorder if you are concerned about the quantity you consume.
Alcohol use disorder is characterized by excessive and prolonged alcohol consumption, an inability to stop drinking, and impairments in social, professional, and personal functioning due to alcohol use .
There is a great deal of research that shows that heavy and prolonged alcohol use causes brain damage, which leads to a significant increase in the risk of developing dementia. The risk is increased with heavy alcohol consumption for prolonged periods of time, so it is highest in those with alcohol use disorder .
Individuals who are not diagnosed with alcohol use disorder, but regularly engage in heavy drinking, of more than 3-4 drinks per day, or binge drinking episodes, in which they consume more than 4-5 drinks in a short period of time, are also at a significantly increased risk of developing dementia .
Additionally, those with alcohol use disorder or who engage in heavy alcohol use are more likely to make poorer health-related choices, such as neglecting to consume appropriate nutrition or engage in exercise, thus increasing their dementia risk due to reduced general wellbeing. Similarly, the risk of stroke and accidental head injury is increased in these groups, which can also lead to dementia .
Heavy alcohol use can also cause alcohol-related brain damage (ARBD), such as alcohol-related ‘dementia’ and Wernicke-Korsakoff syndrome, which cause similar symptoms to dementia, such as short-term memory loss, inability to learn new information, mood changes, and mobility issues .
However, unlike dementia, it is possible to improve or recover from these conditions with appropriate treatment and abstaining from alcohol use, thereby improving cognitive function, and reducing the risk of dementia .
Studies show that around 10% of people with dementia have ARBD, which can cause the occurrence of cognitive impairments at a younger age, thus contributing to an increased risk of young-onset dementia .
Prolonged and heavy alcohol use causes brain cell death, which can cause certain areas of the brain to shrink. For example, research has found that heavy drinkers have a reduced volume of white matter. This damage leads to poorer communication between areas of the brain and impaired cognitive function. If this is untreated, it can lead to mild cognitive impairment or various types of dementia, such as Alzheimer’s disease .
Long-term heavy alcohol use also causes reduced levels of thiamine (vitamin B1), which is necessary for proper brain functioning. This can lead to Wernicke-Korsakoff syndrome, which begins with Wernicke’s encephalopathy, a swelling of the brain. If left untreated, Wernicke’s encephalophathy leads to Korsakoff syndrome, which results in symptoms similar to those of dementia .
Various studies have been conducted to ascertain the effects of alcohol use on the development of dementia. Although excessive and prolonged alcohol consumption significantly increases the risk of dementia, there are variable opinions about the impact of mild to moderate alcohol consumption .
For example, there are several studies that suggest mild to moderate alcohol use (1-14 units per week) can even lower the risk of dementia. Some research also indicates that a complete abstinence from alcohol can increase the risk of dementia compared to mild to moderate use .
However, these studies vary in their results due to the differences in the regularity of assessments, definitions of consumption amounts, length of the studies, and changes in consumption throughout lifetimes. As such, it is not clear if mild to moderate alcohol use can decrease the risk of dementia, although it is widely accepted that this level of alcohol use does not increase the risk .
It is important to note that although mild to moderate use of alcohol may have no impact on the development of dementia, research does suggest that any use of alcohol can contribute to an increased risks of other health conditions, such as cancer and harmful behaviors .
Different countries have slightly differing guidelines on safe alcohol consumption, but it is generally considered that up to 14 units per week is a safe quantity. Anything above 14 units per week has been found to increase the risk of dementia, alcohol-related brain damage, cancer, cardiovascular disease, and stroke .
Some guidelines state that males can safely drink a slightly larger amount than females, equating to 2 drinks per day or 21 units per week for males, and 1 drink per day, or 14 units per week for females .
One unit equates to 10ml or 8g of pure alcohol. For example, a standard glass of wine (175ml), a pint of beer, and a double shot of a spirit (50ml) each equate to 2 units, although this may vary depending on the strength of the alcohol .
Although guidelines state that up to 14 units per week is safe, this should be spread out over at least 3-4 days, rather than being consumed all at once, as this would be considered a binge drinking episode, which is also very harmful. For example, even if no alcohol is consumed for several days or weeks, and then many units are consumed on one occasion, this can still increase health risks .
It is not safe to drink alcohol if you are under the legal drinking age, pregnant, taking medications that can interact with alcohol, or are recovering from an alcohol or substance use disorder .
If you consume a mild to moderate amount of alcohol, there is no evidence to suggest that you are at an increased risk of developing dementia. However, there may be other associated health risks, so you may wish to consider reducing your alcohol intake .
If you consume a large amount of alcohol, regularly engage in binge drinking, or have an alcohol use disorder, you may wish to seek professional advice on how to reduce or stop your drinking. Professional support can particularly helpful if you are noticing impairments that may be related to your alcohol use, such as memory loss, changes in mood, or mobility issues, or it is negatively impacting your social or professional life.
Recovering from alcohol use disorder can be challenging and what works for one person may not work well for another, so you may wish to try different treatment options .
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