According to a US study, our mental powers peak around age 22. After a short period of relative stability, a marked decline is first seen around age 27.
Professor Timothy Salthouse of Virginia University has done a seven-year study with 2,000 healthy subjects aged between 18 and 60.
The mental powers of the participants were tested using puzzles, recalling words and details of stories en recognizing patterns in letters and symbols. These tests are already in use by doctors to detect dementia.
In an article in
Neurobiology of Aging Professor Salthouse reports that in 9 tests of 12, top performance was achieved at age 22, on average, whereas the first marked decline happened at 27 in tests of brain speed, reasoning and the ability to solve visual puzzles.
Memory, on the other hand, stayed intact until people were 37 years old, on average.
These declines in abilities, however, were not so obvious in other fields where the abilities are based on accumulated knowledge, for example tests of general information or vocabulary. Results on these tests actually increased until the subjects were 60 years old.
According to the
BBC, Rebecca Wood of the Alzheimer's Research Trust agrees with the findings and says:
"This research suggests that the natural decline of some of our mental abilities as we age starts much earlier than some of us might expect - in our 20s and 30s.
"Understanding more about how healthy brains decline could help us understand what goes wrong in serious diseases like Alzheimer's.
"Alzheimer's is not a natural part of getting old; it is a physical disease that kills brain cells, affecting tens of thousands of under 65 too.
"Much more research is urgently needed if we are to offer hope to the 700,000 people in the UK who live with dementia, a currently incurable condition."
