Half of Americans use a drink linked to dementia on any given day. Both sugary and artificially sweetened 'diet' drinks are linked to dementia by two new studies. People who drink sugary beverages tend to have poorer memories, smaller brains and a smaller hippocampus (an area vital for learning and memory). Diet sodas, though, don't seem much safer. A follow-up study found that people who drink diet sodas are three times more likely to develop dementia and stroke, compared to those who drink none. Both studies show associations, so it doesn't prove cause and effect. Professor Sudha Seshadri, who led the research, said: "These studies are not the be-all and end-all, but it's strong data and a very strong suggestion. It looks like there is not very much of an upside to having sugary drinks, and substituting the sugar with artificial sweeteners doesn't seem to help. Maybe good old-fashioned water is something we need to get used to." Excess sugar intake has long been linked to obesity,