Monday, August 14, 2017
Moderate Alcohol consumption may cause decline in brain health
A new study concludes that even moderate alcohol consumption is linked to a raised risk of faster decline in brain health and mental function. Compared with people who did not drink, people who drank moderately showed three times higher risk of brain decline.
The researchers also found that, compared with abstinence, light drinking (defined as no more than 7 units per week) - offered no protective effect against brain decline.
The researchers explained that a link between heavy drinking and adverse brain health - including dementia and degeneration of brain tissue - has already been well established. However, fewer studies have examined the relationship between moderate drinking and brain health, and their evidence was largely inconsistent.
The researchers say that their findings support the United Kingdom's recent tightening of guidance on alcohol and question the limits given in the United States guidelines. Individuals will make their own judgments as to risks they are willing to accept from alcohol, whether to drink alcohol and how much and how often to drink. These guidelines should help people to make informed choices.
Three independent groups of experts met over a 2½ year period to consider the evidence on the health effects of alcohol; and whether this could form the basis of new advice to the public
The UK Chief Medical Officers considered and accepted the advice of the expert group and agreed on 3 main recommendations:
• A weekly guideline on regular drinking;
• Advice on single episodes of drinking; and
• A guideline on pregnancy and drinking.
New weekly guideline [this applies for people who drink regularly or frequently i.e. most weeks]. The Chief Medical Officers’ guideline for both men and women is that:
• You are safest not to drink regularly more than 14 units per week, to keep health risks from drinking alcohol to a low level.
• If you do drink as much as 14 units per week, it is best to spread this evenly over 3 days or more. If you have one or two heavy drinking sessions, you increase your risks of death from long-term illnesses and from accidents and injuries.
• The risk of developing a range of illnesses (including, for example, cancers of the mouth, throat, and breast) increases with any amount you drink on a regular basis.
• • If you wish to cut down the amount you’re drinking, a good way to help achieve this is to have several drink-free days each week.
The image below shows what is a standard unit:
The newest evidence (available since the previous guidelines were published in 1995) suggests:
• Benefits for heart health of drinking alcohol are less and apply to a smaller group of the population than previously thought.
o The only group with potential to have an overall significant reduction in risk of death in the UK is women over the age of 55 (especially if drinking around 5 units a week or less)
• There are adverse effects from drinking alcohol on a range of cancers
o This was not fully understood in 1995 – and these risks start from any level of regular drinking and then rise with the amounts of alcohol being drunk
On single drinking episodes [this applies for drinking on any single occasion). The Chief Medical Officers advise men and women who wish to keep their short-term health risks from a single drinking occasion to a low level that they can reduce these risks by:
• Limiting the total amount of alcohol, you drink on any occasion
• Drinking more slowly, drinking with food, and alternating with water
• Avoiding risky places and activities, making sure you have people you know around
• Ensuring you can get home safely
Some groups of people are likely to be affected more by alcohol and should be more careful of their level of drinking on any one occasion:
• Young adults
• Older people
• Those with low body weight
• Those with other health problems
• Those on medicines or other drugs
As well as the risk of accident and injury, drinking alcohol regularly is linked to long-term risks such as heart disease, cancer, liver disease, and epilepsy.
The researchers say in their study that “Our findings support the recent reduction in UK safe limits and call into question the current US guidelines, which suggest that up to 24.5 units a week is safe for men, as we found increased odds of hippocampal atrophy at just 14-21 units a week, and we found no support for a protective effect of light consumption on brain structure. Alcohol might represent a modifiable risk factor for cognitive impairment, and primary prevention interventions targeted to later life could be too late.”
What is already known on the issue of drinking
• Heavy drinking is associated with Korsakoff’s syndrome, dementia, and widespread brain atrophy
• While smaller amounts of alcohol have been linked to protection against cognitive impairment, few studies have examined the effects of moderate alcohol on the brain
• Previous studies have methodological limitations especially regarding the lack of prospective alcohol data, have been conflicting, and have failed to provide a convincing neural correlate
What this study adds
• Compared with abstinence, moderate alcohol intake is associated with increased risk of adverse brain outcomes and steeper cognitive decline in lexical fluency
• The hippocampus is particularly vulnerable, which has not been previously linked negatively with moderate alcohol use
• No protective effect was found for small amounts of alcohol over abstinence, and previous reports claiming a protective effect of light drinking might have been subject to confounding by associations between increased alcohol and higher social class or IQ