Simple Brain Training Cuts Dementia Risk by 25%

A short, accessible brain training program could significantly reduce the risk of dementia, according to a recently published study, the conclusions of which are however viewed with caution by part of the scientific community. The research, conducted over two decades, suggests that exercises targeting reaction speed could have a real impact on cognitive health in old age.

In recent years, the market for "brain training" apps and games has exploded, many of which promise to slow cognitive decline or even prevent dementia. However, few rigorous, long-term scientific studies have been able to demonstrate the real effectiveness of such interventions. The new study, published in the journal Alzheimer's and Dementia: Translational Research & Clinical Research, is notable precisely for its length and scope. Initiated in the late 1990s, the project included more than 2,800 participants over the age of 65, randomly assigned to several cognitive training groups or a control group.

Participants initially attended one-hour training sessions, twice a week, for five weeks. Then, after one year and after three years, they participated in booster sessions. In total, the actual training time did not exceed 24 hours. The exercises targeted three areas: memory, reasoning and information processing speed. Of these, only speed training produced notable long-term results.

• Speed training, the most effective

After assessments carried out at five, ten and twenty years, the researchers found that the participants who followed the speed training - consisting, for example, in quickly identifying images of cars and road signs displayed on a screen - recorded the best results. "Speed training seemed to be the most beneficial,” said Marilyn Albert, a co-author of the study and a researcher at Johns Hopkins University in Baltimore. After two decades, people who followed this type of exercise and the booster sessions had a 25 percent lower risk of developing dementia. According to the researcher, the positive effects could be explained by an improvement in brain connectivity. "We assume that the training had an impact on the way different regions of the brain communicate with each other,” explained Marilyn Albert.

• Caution in interpreting the results

Despite the authors' enthusiasm, other specialists point out the limitations of the study. Rachel Richardson, a researcher at the Cochrane Collaboration, pointed out that although the result is statistically significant, the real effect may be more modest than the 25 percent percentage suggests, given the margins of error. Baptiste Laurent, an expert in medical statistics at University College London, cautioned that a positive result in a subgroup does not, in itself, constitute definitive proof of the overall effectiveness of the method.

• Potentially major impact on health systems

Even so, the study authors consider the findings "extremely important.” According to their estimates, a 25% reduction in the risk of dementia in the American population could generate savings of about $100 billion for the US health system. Discovering the exact mechanisms underlying the effectiveness of speed training could pave the way for the development of even more effective cognitive exercises in the future. According to the World Health Organization (WHO), dementia currently affects an estimated 57 million people globally and is the seventh leading cause of death in the world.