While it's true that people who did not drink, or who had the occasional glass, were also found to be more likely to develop dementia, we cannot say that alcohol protects against dementia. We do not know how much they drank when they were younger. These higher-risk people may have stopped drinking because of health worries, or possibly because some had concerns about their alcohol use when they were younger. Also, it's worth noting that those who did not drink alcohol and did not have cardiovascular disease or diabetes were not at increased risk of dementia.