Cognitive training could arm the brain against the effects of dementia Gary Burchell/Getty Images Cognitive “speed training” can reduce the risk of a dementia diagnosis by 25 per cent – that’s according to results from the world’s first randomised controlled trial of any intervention against the condition. “There was a lot of scepticism about whether or not brain training interventions were beneficial, and to me, [our study] answers the question that they are,” says Marilyn Albert at Johns Hopkins University School of Medicine in Baltimore, Maryland. Brain training has generated controversy for years. Early enthusiasm waned after several brain-training companies that had promised protection against cognitive decline were found to be overstating their benefits. In 2014, almost 70 scientists signed an open letter saying that there was no conclusive evidence that brain training produced changes that had real-world relevance or promoted brain health. Months later, another open letter signed by more than 100 scientists countered their arguments. Now, a 20-year study of 2832 people aged 65 and older suggests specific exercises may offer benefits. The …