Study monitored more than 4,000 people for ten years
People who enjoy diet drinks daily are significantly increasing their chances of suffering a stroke or dementia , research suggests.
Scientists found those having one or more artificially sweetened drinks a day were almost three times more at risk than those consuming fewer than one a week.
The findings were based on data from more than 4,300 people.
Matthew Pase, of Boston University School of Medicine, said: “Our study shows a need to put more research into this area, given how often people drink artificially sweetened beverages.
“Although we did not find an association between stroke and dementia and the consumption of sugary drinks, this certainly does not mean they are a healthy option.”
The research, published in journal Stroke, is based on a heart health study involving residents in Framingham, Massachusetts.
Scientists have issued warning over diet drinks
All participants reported on their food and drink intake at three separate points during the 1990s. They were monitored for 10 years, with 97 cases of stroke among over-45s and 81 cases of dementia in over-60s. Results were adjusted for other risk factors like age, gender, exercise and smoking.
Dr Pase added: “We recommend that people drink water on a regular basis instead of sugary or artificially sweetened beverages.”
Meanwhile, NHS England will ban hospital shops from stocking sugary drinks next year unless retailers voluntarily take action to cut their sales.
Cans and bottles of sugary soft drinks will be targeted, as well as sugary drinks made in NHS cafes and canteens such as coffees with sugar syrup.
Other drinks that will be hit by the move are those with added sugar, including fruit juices with extra sugar, and sugary milk drinks, depending on their total milk content.
NHS England said such drinks would be banned unless further voluntary action is taken to cut sales.
Firms that have agreed to reduce sugary drinks to 10% or less of total drink sales in their hospital shops include WH Smith, Marks & Spencer, Greggs and Subway.
Medirest, which supplies NHS hospitals with ready meals and brings in chains such as Costa, is also on board, as is ISS, which supplies food for patients, staff and visitors, and the Royal Voluntary Service, which runs some hospital shops.
NHS England chief executive Simon Stevens said: "A spoonful of sugar may help the medicine go down but spoonfuls of added sugar day-in, day-out mean serious health problems.