When the researchers probed deeper into the association, drinking 40g of ethanol per day — the equivalent to five units — was linked with a lower risk of dementia compared to those who had never had a tipple.
There are limitations to the study that need flagging. The researchers said their data was robust and shows the impact of alcohol drinking on dementia rates worldwide.
However, they noted that alcohol intake was self-reported by participants — who are prone to under-estimate their drinking.
And the type of alcohol consumed was not logged. Some studies have found that only certain drinks — such as wine — may protect against dementia.