Brain-Training Exercise Could Reduce Dementia Risk by 25 Percent

A straightforward brain-training activity may lower people’s likelihood of developing dementia by 25 percent, according to a study published on Monday, although independent researchers urged caution over the interpretation of its findings.

A huge range of brain-training games and apps claim to prevent cognitive decline, but there has been limited high-quality, long-term evidence demonstrating that they work.

The new research was a randomised controlled trial - regarded as the gold standard in medical research - that began recruiting participants in the late 1990s.

More than 2,800 adults aged 65 and over were randomly allocated to one of three forms of brain training - speed, memory or reasoning - while others were assigned to a control group.

Participants initially completed one-hour training sessions twice weekly for five weeks. They then received four booster sessions after one year and again after three years. Altogether, the training involved less than 24 hours.

At follow-ups conducted after five, 10 and, most recently, 20 years, speed training consistently proved "disproportionately beneficial", Marilyn Albert, a study co-author at Johns Hopkins University in the United States, told AFP.

Speed training and dementia risk

After 20 years, Medicare records indicated that participants who completed the speed-training activity and booster sessions had a 25-percent lower risk of developing dementia, the study found.

Neither of the other two training approaches produced a statistically significant difference.

"For the first time, this is a gold-standard study that's given us an idea of what we can do to reduce risk for developing dementia," Albert said.

However, Rachel Richardson, a Cochrane Collaboration researcher who was not involved in the research, warned that "while statistically significant, the result may not be as impressive" as a 25-percent reduction.

She told the Science Media Centre that this was partly because the margins of error "range from a reduction of 41 percent to one of only five percent".

Richardson also noted that people with conditions including impaired eyesight or hearing were excluded from the study, meaning its participants may not have been fully representative.

Baptiste Leurent, a medical statistics specialist at University College London, said the research had "substantial limitations".

"Although one subgroup analysis produced a significant result, this single finding is not generally regarded as strong enough evidence to demonstrate the intervention's effectiveness," he said.

"Further research is still needed to determine whether cognitive training can reduce the risk of dementia."

‘Connectivity in the brain’

The speed-training task requires participants to click on cars and road signs appearing in different parts of a computer screen.

Albert said the team did not know why this particular activity seemed to be more effective.

"We assume that this training affected something about connectivity in the brain," she said.

Identifying the precise reason why speed training worked could enable researchers to create a new and more effective exercise in future, Albert said.

She added that the results applied only to this particular task and did not suggest anything meaningful about other brain-training games.

Potential impact of dementia reduction

Albert stressed that the finding was "extraordinarily important", saying that reducing dementia among 25 percent of the US population could save $100 billion in patient care.

According to the World Health Organization, dementia affects 57 million people and is the seventh leading cause of death worldwide.

The study appeared in the journal Alzheimer's and Dementia: Translational Research & Clinical Research.

© Agence France-Presse