Excessive intake of sugar has been linked to a huge variety of health problems, many of them a consequence of the obesity that’s also linked to excessive sugar. That’s led many people to switch to drinks with artificial sweeteners that aren’t metabolized by the body. A new study is now suggesting that these sweeteners are associated with their own health risks, namely stroke and dementia. But the study doesn’t get into causality, and there’s enough oddities in the data to suggest that it’s not time to purge your fridge just yet.

The study, run by a collaboration of Boston-based researchers, relied on a cohort of individuals that had been recruited starting in 1971. On average, every four years since, the participants have completed follow-up surveys and had their health checked out. Over 5,000 people are in this cohort, and they provide a rich source of epidemiological data.

The authors started out intending to look at whether sugar-rich drinks increased the risk of strokes and dementia. So they eliminated a lot of people from this cohort because they’d previously experienced these or related issues. That reduced the study population considerably: under 3,000 for stroke, and under 1,500 for dementia.