Taking medication to lower blood pressure reduces a person's risk of developing cognitive impairment and dementia, new Irish research has found.

Researchers at NUI Galway analysed 14 trials involving over 96,000 people. They found that when blood pressure was lowered after taking blood pressure (antihypertensive) medications, the risk of developing cognitive impairment was reduced by 7% over a four-year period, while the risk of developing dementia was also reduced by 7%.

"When you consider how common dementia is in the population (50 million people worldwide), effective treatment and control of hypertension (high blood pressure) would have a major impact on preventing dementia.

"Our findings emphasise the need for more effective screening, prevention, and treatment of hypertension, which remains suboptimal in Ireland," commented the study's joint first author, Dr Conor Judge.

He pointed to The Irish Longitudinal Study on Ageing (TILDA), an ongoing study of people over the age of 50 in Ireland, which has shown that two in three people over the age of 50 here have high blood pressure.

"Of these, half are unaware of the diagnosis, and one-third are not on treatment. This is a major care gap," he noted.

This latest study set out to estimate how much the risk of dementia can be reduced by taking medications to lower blood pressure if you have been diagnosed with high blood pressure.

Lowering blood pressure reduces the risk of stroke and heart disease and according to the researchers, the prevention of dementia can now be added to that list.

They emphasised that currently, there are no available therapies that directly prevent dementia, so this study highlights the importance of blood pressure in the risk of dementia.

According to Dr Michelle Canavan, a consultant geriatrician at Galway University Hospital, and senior author of the paper, the prevention of dementia "is a major health priority".

"We know from previous research that a major concern of older people is developing dementia. The message from this study is simple - get your blood pressure checked. If it is high, it can be readily treated with lifestyle changes and medications.

"We would hope that our study will heighten awareness of the importance of controlling blood pressure to maintain brain health, combined with a healthy lifestyle," she said.

Details of these findings are published in the Journal of the American Medical Association (JAMA).