Tackling crosswords and puzzles can help 80-year-olds to retain the brain-power of a 70-year-old and even delay dementia, researchers believe.
A study looking at the benefits of brain training found nearly three-quarters of those who took part displayed cognitive benefits a decade on.
This is the first study of its kind to show how a little training goes a long way.
The 10-year US study involved 2,800 participants, with an average age of 74. Participants were split into groups: some received brain training focusing on processing speed, others on memory and others on reasoning ability. A fourth group did not get any training.
All four groups were given 10 sessions lasting 60 to 70 minutes over five or six weeks and nothing else for the next decade.
Results showed that around 60pc of those who participated in the brain drills said they had less difficulty with day-to-day activities such as shopping, compared to 49pc of those who did not have the training.
George Rebok, an expert on ageing and a professor at Johns Hopkins University in Baltimore, said: "Ten years after the training, the effects were durable for the reasoning and the speed training."
The report is published in the 'Journal of the American Geriatrics Society'. (© Daily Telegraph, London)