Teetotalism in midlife makes you more likely to develop dementia? What the research actually says

The estimable Tony Rao of Kings College London gets to the truth. “In this study, abstainers with higher levels of illnesses such as heart disease, diabetes and obesity were those at highest risk of dementia. It may be that having a physical illness is the reason that these people abstained from alcohol. Drinking may just be a red herring,” he writes, adding that the study did not include  people who drank heavily under age 35 or above 55.