Both Heavy Drinking and Abstinence Could Raise Risk of Dementia, Study Suggests

Both abstaining from alcohol and drinking excessively have been linked in a study to the risk of developing dementia.

The research comes as scientists attempt to find a cause, treatment and cure for dementia: the umbrella term for neurodegenerative diseases—the most common of which is Alzheimer's. Some 5.7 million Americans currently have Alzheimer's disease, and this figure is expected to rise to 14 million by 2050.

Past studies have indicated that drinking in moderation could lower the risk of dementia, while not drinking alcohol and drinking heavily could have the opposite effect. But the reason why isn't exactly clear.

So an international team of researchers assessed data collected on 9,000 British civil servants between 1985 to 1993, who were who were aged between 35 and 55 at the start of the study. Of the total participants, 387 were eventually diagnosed with dementia, at an average age of 76.

An international team of researchers have investigated whether drinking alcohol in middle age can raise an individual's risk of developing dementia. Getty Images

Dr. Servine Sabia of the department of epidemiology and public health at the French National Institute of Health and Medical Research (Inserm) and co-author of the study told Newsweek: "Most previous studies on the association between alcohol consumption and risk of dementia are based on elderly populations where drinking habits may have been modified at older ages.

"Given the long latent phase of dementia it is important to consider how alcohol consumption over adulthood shapes the risk of dementia."

Read more: Skinny Fat Body Type Linked to Dementia Risk in Study

The data suggested not drinking alcohol in midlife or drinking more than 14 units per week carried a higher chance of dementia compared with those who drank between one to 14 units. And every seven units an individual went above the 14 unit threshold was linked with a 17 percent increased risk of dementia from the baseline.

However, Sabia cautioned the results should not motivate people who do not drink to start.

"These findings should be considered along with other results that show a detrimental effect of alcohol consumption on mortality, neuropsychiatric disorders, cirrhosis of the liver and cancer. In addition, we cannot exclude the possibility that persons abstaining from alcohol in midlife may have been previous drinkers."

She also stressed that, as the study was observational, it does not definitely prove that drinking alcohol or abstaining changes a person's risk of developing dementia.

"However, given the detrimental effect of alcohol for several health outcomes, people who drink in an excessive manner should be encouraged to reduce their alcohol consumption," she said.

Dr. Doug Brown, chief policy and research officer at Alzheimer's Society, who was not involved in the research, said: "By finding evidence that drinking lots of alcohol, and also drinking no alcohol at all both increase dementia risk, this study supports other work that continues to question whether drinking up to the equivalent of six glasses of wine per week might have a protective effect against dementia."

But he agreed that the observational nature of the study means more trials are needed to explore whether this is actually the case.

"While this study does throw up questions about alcohol and dementia, there could be other risk factors at play. What we do know is that excessive drinking is a proven cause of liver disease and cancers. We recommend that people enjoy a drink responsibly, but don't overdo it."

Dr. Sara Imarisio, head of research at charity Alzheimer's Research UK who did not work on the paper, said: "Past studies of alcohol and dementia risk have tended to record how much people drink at a single point in time, but the strength of this study is that the researchers have been able to track changes in people's drinking over a number of years during midlife.

"As this study only looked at people's drinking in midlife, we don't know about their drinking habits earlier in adulthood, and it is possible that this may contribute to their later life dementia risk. People who completely abstain from alcohol may have a history of heavy drinking and this can make it difficult to interpret the links between drinking and health. Future research will need to examine drinking habits across a whole lifetime, and this will help to shed more light on the relationship between alcohol and dementia."

A healthy lifestyle that includes cutting down on excessive drinking and boost overall health and reduce the risk of dementia, she said.

"A good motto tends to be, what is good for your heart is good for your brain," she concluded. "Not smoking, eating a healthy balanced diet, staying mentally and physically active and keeping blood pressure and cholesterol in check are all ways to support healthy brain aging."