Drinking up to a pint-and-a-half of beer a day may reduce the risk of death for people in the early stages of Alzheimer’s, a study has found, although it is possible that the survivors are simply more sociable.

The study, published by the online British Medical Journal Open, drew on a three-year-long Danish study of 330 people living with Alzheimer’s or early stage dementia.

Nearly three-quarters of the people drank one or fewer units of alcohol a day, but those who drank two to three units had a 77 per cent lower risk of death compared with those who drank least.

Cautiously interpreting the findings, the authors said there is “a potential correlation” between consumption of two to three units of alcohol per day and a lower risk of death among some Alzheimer’s patients.

The results were found to be reliable even after age, gender, general health, smoking, and whether the subject lived alone or with a carer were taken into account.

Researchers offered a number of possible explanations, including perhaps that those who drink moderately “have a richer social network which has been linked to improved quality, and possibly length, of life”.