A new study suggests that a high blood pressure drug has the potential to slow down Alzheimers disease by improving the flow of blood to parts of the brain linked to memory.

Researchers at Radboud University in the Netherlands noted that the drug nilvadipine increased blood flow to the brains memory and learning centre among people with Alzheimers without affecting other parts of the brain.

The findings are published in the journal Hypertension and suggest that the known decrease in cerebral blood flow in patients with Alzheimers can be reversed in some regions.

An important question is whether this observed increase in cerebral blood flow translates to clinical benefits, said the researchers.

Previous research suggests that blood flow to the brain declines in early Alzheimers disease. Nilvadipine is a calcium channel blocker used to treat high blood pressure.

Researchers set out to ascertain whether nilvadipine could help treat Alzheimers disease by comparing the use of nilvadipine and a placebo among people with mild to moderate Alzheimers disease.

Overall, 44 participants were randomly assigned to receive either nilvadipine or a placebo for six months. Neither researchers nor the participants knew who received the drug or the placebo that was evenly divided among the two groups.

Blood flow to specific regions of the brain was measured at study initiation and six months thereafter using a unique magnetic resonance imaging (MRI) technique.

It was noted that blood flow to the hippocampus -- the brains memory and learning centre -- increased by 20 per cent among the nilvadipine group compared to the placebo group. Blood flow to other regions of the brain was unchanged in both the groups.

"This high blood pressure treatment is promising as it doesnt appear to decrease blood flow to the brain, which could cause more harm than benefit," said Jurgen Claassen, associate professor at Radboud University Medical Center.

"While no medical treatment is without risk, getting treatment for high blood pressure could be important to maintain brain health in patients with Alzheimers disease," Claassen stated.

However, researchers note that sample sizes were too small and follow-up time too short to reliably study the effects of this cerebral blood flow increase on structural brain measures and cognitive measures.

Study participants were screened between 2013 and 2015 as part of a larger research project comparing nilvadipine to placebo among more than 500 people with mild to moderate Alzheimers disease.

In that larger project, effects on cerebral blood flow were not measured. Overall, no clinical benefit was noted with use of nilvadipine. However, a subgroup of patients with only mild symptoms of disease did show benefit, with a slower decline in memory.

Previous studies have hinted that high blood pressure treatment could reduce the risk of developing dementia. The researchers think that beneficial effects on brain blood flow could explain part of this effect. (PTI)