Learn how drinking too much alcohol can damage the brain and increase a person's risk of developing dementia.
Does alcohol increase the risk of dementia?
There is enough evidence to show that excessive alcohol consumption increases a person’s risk of developing dementia.
Drinking alcohol in moderation has not been conclusively linked to an increased risk of dementia. If you already drink alcohol within the recommended guidelines, you do not need to stop on the grounds of reducing the risk of dementia.
Despite some claims, drinking alcohol in moderation has not been shown to offer significant protection against developing dementia. So if you do not currently drink alcohol, you should not start as a way to reduce dementia risk.
How to reduce the risk of dementia
A lifelong approach to good health is the best way to lower your risk of dementia.
There are some lifestyle behaviours with enough evidence to show that changing them will reduce your risk of dementia.
Reduce your risk of dementia
How alcohol can damage the brain
Drinking alcohol is linked to reduced volume of the brain's white matter, which helps to transmit signals between different brain regions. This can lead to issues with the way the brain functions. Alcohol consumption above recommended limits (of 14 units per week) over a long period of time may shrink the parts of the brain involved in memory. Drinking more than 28 units per week can lead to a sharper decline in thinking skills as people get older.
Long-term heavy drinking can also result in a lack of vitamin B1 (thiamine) and Wernicke-Korsakoff syndrome which affects short-term memory.
Alcohol-related brain damage (ARBD) is a brain disorder which covers several different conditions including Wernicke-Korsakoff syndrome and alcohol-related dementia. It is caused by regularly drinking too much alcohol over several years.
Guidelines for moderate drinking
Moderate alcohol consumption is normally defined as 1-14 units of alcohol per week for women and 1-21 units a week for men. If you regularly drink much more than this, you are increasing your risk of damage to your brain and other organs, and so increasing your risk of dementia.
Current NHS guidelines state that both men and women should limit their intake to 14 units a week. A unit is dependent on the amount of pure alcohol in a given volume and can be calculated for specific drinks.
Units are based on typical alcohol by volume (ABV) content. However, this does vary. If you’re buying a bottle or can, it’s helpful to check the ABV content on the label.
The NHS basic guideline for units of alcohol is as follows:
- A typical glass (175ml) of (12% ABV) wine: 2 units.
- A large glass of (250ml) of (12% ABV) wine: 3 units.
- A pint of lower (3.6% ABV) alcohol beer or cider: 2 units.
- A pint of higher (5.2% ABV) alcohol beer or cider: 3 units.
- A single shot (25ml ABV) of spirits such as whisky, gin or vodka (40%): 1 unit.
If you regularly drink alcohol, try to do so in moderation and within recommended limits.
- Set yourself a weekly alcohol limit and keep track of how much you’re drinking.
- Have several alcohol-free days each week.
- Try low-alcohol or alcohol-free drinks, or smaller sizes of drinks.
- Try to alternate between alcoholic and non-alcoholic drinks like cola, water or juice.
- Let your friends and family know that you're cutting down and how they can support you. This can make it easier to drink less, especially at social events.
- Take advantage of particular dates and events to motivate you. For example, you could make a New Year’s resolution to drink less.
Several high-profile reviews looked at the research into alcohol and dementia risk. They all found that people who drank heavily or engaged in binge drinking were more likely to develop dementia than those who drank only moderate amounts.
These reviews were the World Alzheimer’s Report 2014, National Institute for Health and Care Excellence (NICE) Guidance and the Lancet Commission 2018. Each combined multiple research studies to reach a consensus on alcohol consumption and the development of dementia.
It is clear that excessive drinking increases a person’s risk of dementia compared with not drinking at all. However, from the evidence collected to date, it is not possible to determine what effect drinking within the NHS-recommended alcohol guidelines has on a person's risk of dementia.
NICE Guidelines recommend that alcohol consumption be reduced as much as possible, particularly in mid-life, to minimize the risk of developing age-related conditions such as frailty and dementia.
There is conflicting evidence about the benefit of drinking in moderation. A small number of studies suggest that individuals who drank in moderation were less likely to develop dementia than those who consumed no alcohol. However other studies suggests that there is no benefit to drinking alcohol.
The studies that claim that alcohol reduces dementia risk compare drinkers with non-drinkers. These often group lifetime non-drinkers with people who have given up alcohol before the time asked about in the study.
People who give up alcohol may have health problems that cause them to stop. This may mean they have an increased dementia risk to lifetime non-drinkers. Combining both into the same group makes the non-drinking group seem like they had a higher risk of dementia than if lifetime non-drinkers were considered separately.
There are some protective effects that alcohol may have on the brain, like thinning the blood and increasing levels of healthy cholesterol in the body. These effects have been suggested to help lower the risk of developing dementia. However, drinking even in moderation has also been associated with a reduction in brain volume. Drinking alcohol may be related to other health conditions.
