The study, which recorded the drinking habits of 9,000 London civil servants between the ages of 35 and 55 from 1985 to 1993, revealed that abstinence in midlife was associated with a 45% higher risk of dementia compared with people who drank between one and 14 units of alcohol per week.
With people who drank more than 14 units a week, the dementia risk increased by 17% with every additional seven units per week.
Guidance from the UK chief medical officer states that men and women should drink no more than 14 units of alcohol each week – the equivalent of around six pints of beer.
'Lifetime study needed'
However, the report did not take into account the drinking habits of the participants before middle age, and its authors concluded the underlying mechanisms that lead to developing dementia for heavy drinkers and those abstaining were probably different.
Dr Sara Imarisio, head of research at Alzheimer's Research UK, said: "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.”
The Society of Independent Brewers (SIBA) welcomed the research and championed the positive impact of moderate drinking on physical and mental wellbeing.
James Calder, head of public affairs at SIBA, said; “It is great to see a piece of research make headlines which backs up the 40 years of evidence on the positive effects of moderate alcohol consumption.
“Not only does moderate, sensible consumption of alcohol reduce the incidence of dementia compared to teetotallers, there is evidence it also has beneficial effects in guarding against Type 2 diabetes, heart disease, stroke, macular degeneration, and many other conditions.
“The social effect and positive benefits to mental health of having a beer with your friends and family in the pub also cannot be overlooked. That’s why SIBA and brewers across the country are backing the Long Live the Local campaign, which aims to cut beer tax and protect that vital national institution – the UK pub.”