Mental decline 'seen in middle-age'
Mental function can begin to decline as early as age 45, according to new research.
The brain's capacity for memory, reasoning and comprehension begins to wane much earlier than previously thought, it suggests. While 60 has been cited as the age people experience a difference in their thinking abilities, the new study found decline could actually hit the middle-aged.
Researchers from the Centre for Research in Epidemiology and Population Health in France and University College London in the UK studied more than 7,000 people over a 10-year period. Published online in the British Medical Journal, their research focused on civil servants aged between 45 and 70 at the start of cognitive testing in 1997 to 1999.
Cognitive function was measured three times over 10 years to assess memory, vocabulary, hearing and visual comprehension skills. Tasks included recalling in writing as many words beginning with the letter S as possible and as many animal names as could be thought of.
All cognitive scores, except vocabulary, declined among all age groups during the study, and there was evidence of faster decline among older people.
In men, there was a 3.6% drop in reasoning after 10 years among those who were aged 45 to 49 at the start of the study and 9.6% among those aged 65 to 70. In women, the decline was 3.6% and 7.4% in the same age groups respectively.
The authors concluded: "Cognitive decline is already evident in middle age (age 45-49)." They added: "Poor cognitive status is perhaps the single most disabling condition in old age."
The researchers said diseases such as dementia were now thought to be the result of long-term changes over at least 20 to 30 years. There is enough evidence already to show the importance of healthy lifestyles and good heart health in impacting on the later risk of dementia.
Dr Anne Corbett, research manager at the Alzheimer's Society, said: "This large, important study adds vital information to the debate over when cognitive decline begins. However, the study does not tell us whether any of these people went on to develop dementia, nor how feasible it would be for GPs to detect these early changes.
"More research is now needed to help us fully understand how measurable changes in the brain can help us improve diagnosis of dementia. An early diagnosis is essential as it can provide access to support and potential treatments which can vastly improve people's quality of life."