Alcohol is a neurotoxin which means it kills nerve cells. Some of these cells are in our brain, and so alcohol kills these too. This is not good news once we already have dementia – we want to preserve as many brain cells as possible. Even without a dementia diagnosis, excessive alcohol has a range of effects on cognition, from mild to severe. The very severe form is known as Korsakoff’s Syndrome and occurs when a heavy drinker with inadequate nutrition becomes deficient in thiamine (vitamin B1) In this condition, short term memory is extremely poor and the person is extremely disabled.
Most drinkers eat well enough but can still develop cognitive problems attributable to over-use of alcohol. These include loss of memory, difficulties with new learning, poor judgement and planning. We are not entirely sure how common alcohol-related brain damage is. However, 10%-12% of people with cognitive impairment have been heavy drinkers. For people under 65, it is the 4th most common cause of dementia; about 22% of younger onset dementias are alcohol-related.
In the past, we expected alcohol intake to drop off as people aged. However, the Baby Boomer generation has high rates of hazardous drinking and we can expect an increase in alcohol-related cognitive impairment as the Boomers transition into old age.
So how much can we drink? Studies suggest that if a man has more than 35 standard drinks, or a woman 28 each week for 5 years they are at risk of brain damage. Subsequent research indicates that even 21 drinks/weeks may be dangerous. (The Ministry of Health recommends a maximum of 10 drinks per week for women and 15 for men).
A standard drink is 100 ml wine, 30 ml spirits and 330 ml beer – not very much! Binge drinking, defined as exceeding five drinks at one session, is more damaging than steady, regular intake; acute intoxication and then withdrawal seems particularly bad for brain cells. However, these studies and recommendations apply to younger people. As we age our brains become more delicate and we do not metabolise alcohol (that is, break it down and dispose of it from the body) as fast, so alcohol is more harmful and the safe drinking level for older people is less than noted above.
Older people are also often taking medication that interacts with alcohol, increasing its effects e.g. causing over-sedation, or interfering with its metabolism, thus aggravating the negative consequences. People with brain damage of any type such as stroke, head injury or dementia have vulnerable brains that make them very susceptible to alcohol’s effects and easily intoxicated on small amounts. Alcohol does not just affect the nervous system but damages many other parts of the body e.g. the liver, stomach, pancreas, heart and blood vessels and is often the cause of falls and incontinence.
However, the good news for people with alcohol-related cognitive impairment is that with abstinence brain function can improve. The is one of the few “reversible” causes of dementia. The longer someone stays off alcohol, the better the cognitive recovery.
There are many ways to stop or reduce drinking. These start with an awareness of the benefits of drinking less (improved sleep, mood, thinking, weight loss, for example) and keeping track of how many drinks we actually have. Practical self-help suggestions are available from family practices, written literature and various websites.
There are support and counselling services in most towns and they are usually easy to find. Older people do well in formal treatment programmes and there is no substance to the belief that older people are harder to treat. And there is no shame in acknowledging when we drink too much and seeking help.
Finally, we have all heard that a little wine is good for your brain, that light to moderate alcohol consumption may cut down your chances of getting Alzheimer’s disease. (The jury is still out on this one). The suggestion is that half to two standard drinks a day could be beneficial, and since these levels of alcohol intake don’t appear to cause damage, we can enjoy it, making sure of course, that the number of drinks doesn’t creep up.