Image caption Could taking an aspirin a day slow brain power decline?

An aspirin a day may slow brain decline in elderly women at high risk of cardiovascular disease, research finds.

Around 500 at risk women, between the ages of 70 to 92, were tracked for five years - their mental capacity was tested at the start and end of the study.

Those taking aspirin for the entire period saw their test scores fall much less than those who had not.

The Swedish study is reported in the journal BMJ Open.

Dr Silke Kern, one of paper's authors, said: "Unlike other countries - Sweden is unique, it is not routine to treat women at high risk of heart disease and stroke with aspirin. This meant we had a good group for comparison."

The women were tested using a mini mental state exam (MMSE) - this tests intellectual capacity and includes orientation questions like, "what is today's date?", "where are we today?" and visual-spatial tests like drawing two interlinking pentagons.

No self-medication

But the report found that while aspirin may slow changes in cognitive ability in women at high risk of a heart attack or stroke, it made no difference to the rate at which the women developed dementia - which was also examined for by a neuropsychiatrist.

Dr Simon Ridley, head of research at Alzheimer's Research UK, said: "The results provide interesting insight into the importance of cardiovascular health on cognition, but we would urge people not to self-medicate with aspirin to try to stave off dementia.

"The study reports no benefit from aspirin on overall dementia rates in the group, and previous trials investigating the potential of drugs like aspirin for dementia have been negative."

Dr Kern added: "We don't know the long term risks of taking routine aspirin. For examples ulcers and serious bleeds may outweigh the benefits we have seen. More work is needed. We will be following up the women in this study again in five years."