Chronic heavy drinking leads to serious risk of dementia, study warns

This article was taken from: https://www.theguardian.com/society/2018/feb/20/chronic-heavy-drinking-leads-to-serious-risk-of-dementia-study-warns

By Sarah BoseleyHealth editor

Questions also raised for moderate drinkers of alcohol about their social habit

Heavy drinkers are putting themselves at risk of dementia, according to the largest study of its kind ever conducted.

Research published in the Lancet Public Health journal provides powerful evidence that people who drink enough to end up in hospital are putting themselves at serious risk of vascular dementia and Alzheimer’s disease. It will also raise questions for moderate drinkers about the possible long-term consequences of their social habit.

The study, which used the French National Hospital Discharge database, looked at more than a million people diagnosed with dementia between 2008 and 2013.

More than a third – 38% of the 57,000 cases of early-onset dementia – were directly alcohol-related and 18% had an additional diagnosis of alcohol use disorders. Overall, alcohol use disorders were associated with a three times greater risk of all types of dementia.

Dr Sara Imarisio, head of research at Alzheimer’s Research UK, said: “As this study only looked at the people who had been admitted to hospital due to chronic heavy drinking, it doesn’t reveal the full extent of the link between alcohol use and dementia risk. Previous research has indicated that even moderate drinking may have a negative impact on brain health and people shouldn’t be under the impression that only drinking to the point of hospitalisation carries a risk.”

Experts said the new research should change attitudes. “What is most surprising about this paper is that it has taken us so long to recognise that alcohol misuse and dependence are such potent risk factors for the development of dementia,” said Robert Howard, professor of old age psychiatry at University College London.

“We have long known that alcohol is directly neurotoxic, thiamine deficiency in alcoholics devastates memory, alcohol-related conditions such as cirrhosis and epilepsy can damage the brain and that vascular brain damage is accelerated by alcohol. Surprisingly, we’ve not traditionally considered alcohol and its misuse as an important risk factor for dementia and we were clearly wrong not to have done so.”

The study was not set up to look at the effects of moderate drinking on people’s dementia risk. But the lead author, Dr Michaël Schwarzinger of the Translational Health Economics Network in France, warned that the research showed damage done to the brain by alcohol is never repaired. Heavy drinkers who had given up alcohol for a time did not reduce their dementia risk, even though they were less likely to die early. “It is very striking that for people who were heavy drinkers and had at least a period of abstinence, the level of risk of dementia is about the same,” he told the Guardian.

That is in line with imaging studies that have shown even moderate drinking has a permanent effect. A study published in the British Medical Journal last yearfound that those who drank 14-21 units a week had three times the normal odds of damage to that part of the brain concerned with memory. Guidance in the UK is not to drink more than 14 units a week.

Advice on alcohol and dementia has been confusing. Some studies have suggested that one or two units a day – perhaps a small glass of wine – could be protective. But Schwarzinger said they were small studies and he personally would question whether that can be so.

“Alcohol is a devastating problem, whatever the organ. Now we can add the brain to the list of liver, kidney and heart,” he said.

“A variety of measures are needed, such as reducing availability, increasing taxation, and banning advertising and marketing of alcohol, alongside early detection and treatment of alcohol use disorders.”

Prof Clive Ballard of the University of Exeter Medical School, UK, writing a commentary for the journal, said: “Their study is immensely important and highlights the potential of alcohol use disorders, and possibly alcohol consumption, as modifiable risk factors for dementia prevention … In our view, this evidence is robust and we should move forward with clear public health messages about the relationship between both alcohol use disorders and alcohol consumption, respectively, and dementia.”

Dr James Nicholls, director of policy and research development at AlcoholResearch UK, said the concerns raised by the study were very serious. “If heavy alcohol use increases the risk of dementia then there are enormous social and economic implications,” he said. “We must recognise that good quality, widely accessible alcohol treatment has important long-term benefits, including reducing the levels of dementia in society. And we must invest in these services, reversing the trend of recent years.”