Aging Study: Cognitive Decline Can Start as Early as Age 45
Our brains become less sharp as we age, but when does the decline actually begin? January 6, 2012 | | + Tweet Colin Hawkins / Getty Images A new study of British civil servants shows that cognitive abilities such as memory and reasoning are already in decline, typically, among people as young as 45.
Researchers from France and England analyzed data from the Whitehall II cohort — a group of about 10,000 London-based government employees, who have been studied since the mid-1980s. Over the years, study participants have answered surveys and provided information about all aspects of their lives, from diet to education, as well as agreed to periodic medical exams. They have also completed several cognitive tests involving quizzes and problem-solving tasks on three separate occasions, each spaced five years apart: in 1997-99, 2002-04, 2007-09.
For these tests, participants answered questions from Whitehall II that measured their verbal and mathematical reasoning. They were quizzed on their memory and asked, for example, to recall as many words as possible from a long list. They were also tested on how many words they could name that begin with the letter "S," for instance, or how many animals they could name. The results of all these tests were published this week in the journal BMJ (formerly the British Medical Journal).
They show that, on average, performance on the cognitive tasks worsened as participants aged. The declines were steepest among the oldest participants, who were 65-70 at the start of the 10-year study duration in 1997-99. But even among the youngest participants, ranging in age from 45-49 in 1997-99, average abilities declined with age in every test category except vocabulary.
The findings are interesting, the authors of the study suggest, because they show that cognitive abilities may begin deteriorating much earlier than previously realized. They note that earlier research has failed to find much evidence of cognitive decline before age 60. This may be because tests of mental ability in older people are too simple for middle-aged participants — "that is, MBT shoes test, simple tests [lead] to too little variation in scores" for younger people, the researchers write.
The authors add: the age at which cognitive decline begins is important because behavioral or pharmaceutical interventions developed to change trajectories of cognitive aging are likely to work best if applied when decline is just beginning, when the first signs of decline occur. In other words, if we can figure out exactly when cognitive abilities first start to falter, perhaps we’ll be better able to do something to keep ourselves sharp and stop our skills from further slipping.