An analysis of more than a million dementia patients has found that chronic heavy drinking puts you at serious risk of developing Alzheimer’s disease. In fact, alcohol use disorders were found to be the biggest avoidable risk factor in the onset of dementia.

There are several types of dementia – a decline in mental ability that impacts daily life – but Alzheimer’s is the most common cause. It affects up to 50 million people worldwide and is the leading cause of disability among those over 60.

But when it comes to the link between dementia and drinking, previous research has had mixed results. While some studies claim that moderate drinking damages the brain, others have suggested that having the odd glass of red wine can actually protect against cognitive decline.

However, the researchers behind this latest research, published in The Lancet Public Health, point out that these studies have methodological issues that likely affected the results.

The new study is the largest of its kind, looking at over a million people with dementia admitted to hospital in France between 2008 and 2013. The researchers found that more than a third – 38 percent – of cases of early-onset dementia were directly related to alcohol. Meanwhile, 18 percent of these cases were accompanied by a diagnosis of an alcohol use disorder.

According to the study, “alcohol use disorders were the strongest modifiable risk factor for dementia onset” for both men and women. What’s more, alcohol use disorders were found to contribute to “all other risk factors for dementia onset”, such as diabetes, high blood pressure, and depression, emphasizing the significant role that alcohol can play in raising dementia risk and the importance of tackling alcohol abuse.

However, unlike many previous studies, this research only looked at the effects of very heavy drinking, focusing on people who had been admitted to hospital due to their alcohol habits. Therefore, it is important to note that lower levels of drinking likely don’t carry the same risk.

“This study in no way suggests that moderate alcohol intake could cause early-onset dementia,” said Doug Brown from the Alzheimer’s Society in a statement.

It is no secret that large quantities of alcohol can damage the brain, often in an irreversible way, so perhaps the results aren't too surprising.

“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,” said University College London’s Robert Howard, a professor of old age psychiatry.

“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.”

While for moderate drinkers the study is no cause for alarm, what it does highlight is the importance of keeping your alcohol consumption within the recommended limits of 14 units per week. That's seven pints of lager or seven 175-milliliter glasses of wine.

According to Sara Imarisio of Alzheimer’s UK; “Although there is no sure-fire way to completely prevent dementia, the best current evidence indicates that as well as only drinking in moderation, staying physically and mentally active, eating a healthy balanced diet, not smoking, and keeping weight, cholesterol and blood pressure in check are all good ways to support a healthy brain as we age.”

By Rachel Baxter

21 FEB 2018, 12:13

Original Article: http://www.iflscience.com/health-and-medicine/heavy-drinking-is-the-biggest-avoidable-risk-factor-in-the-onset-of-dementia/