This morning has seen alarming headlines about an alleged connection between artificial sweeteners and dementia. This follows the publication of a study in the United States.

The Framingham Heart Study involved 4,300 people and was published in Stroke, the journal of the American Heart Association.

Headlines have suggested a tripling of the risk of dementia for people who consume at least one artificially sweetened drink a day. Examples include the Daily Mail and a more nuanced article in the Independent.

Dr Liz Coulthard, consultant senior lecturer in dementia at the Bristol Brain Centre (University of Bristol and North Bristol NHS Trust), said, "Although interesting, this paper does not tell us that artificially sweetened drinks cause stroke or dementia. The statistical relationship between artificially sweetened drinks and dementia disappears when the analysis controls for diabetes. This makes it more likely that there is a group of people who both use artificially sweetened drinks and are at higher risk of dementia, presumably because they have a risk factor, such as diabetes, for which a low sugar diet has been recommended. 

While the stroke effect remains even after diabetes has been taken into account, we should bear in mind that this is just one study with relatively small subgroups of participants. There is still strong evidence that high sugar intake is bad for general health. Nevertheless, it is good to question our assumptions about replacing sugar and future research could clarify the relationship between artificially sweetened drinks and neurological disease.