A study conducted by the George Institute for Global Health and the University of New South Wales (UNSW) suggests that lowering blood pressure in later life can cut the risk of dementia.

Dementia is a syndrome in which there is a deterioration in cognitive function beyond what might be expected from the usual consequences of biological aging.

Currently, more than 55 million people live with dementia worldwide, and there are nearly 10 million new cases ­every year, according to the World Health Organization.

The study revealed on Wednesday is based on an analysis of five double-blind placebo-controlled randomized trials that used different blood pressure-­lowering treatments and followed patients until the development of dementia. The trials involved a total of 28,008 individuals from 20 countries and regions with an average age of 69 and a history of high blood pressure. The mid-range of follow-up was just over four years.

"We found there was a significant effect of treatment in lowering the odds of dementia associated with a sustained reduction in blood pressure in this older population," said Ruth Peters, associate professor at UNSW Sydney and program lead for dementia in the George Institute's Global Brain Health Initiative.

"Our results imply a broadly linear relationship between blood pressure reduction and lower risk of dementia, regardless of which type of treatment was used."

She noted that it still remains unknown whether additional blood pressure lowering in people who already have it well-controlled or starting treatment earlier in life would reduce the long-term risk of dementia.

Given the large number of people suffering from dementia worldwide and the lack of major breakthroughs in treatment, the researchers thought reducing the risk of developing the disease would be a welcoming step forward.

They also hoped the results of the study would help in designing relevant public health measures.