Researchers have long thought that cognition — the means of acquiring and processing information about ourselves and our surroundings, which includes memory and other functions we take for granted — starts gradually declining when individuals reach their late 70s.
Poor cognition is regarded as one of the most disabling conditions affecting the elderly and is typically associated with other age-related health problems, such as dementia.
Scientific literature has typically concluded that little evidence of cognitive decline before the age of 60 existed, although that opinion was not universally accepted by experts. There were reportedly frequent debates as to the age when cognition began diminishing.
A new study, published in the British Medical Journal, finds that cognitive decline begins at 45.
Because there have been few studies examining data regarding age-related decline gathered over several years, this is exactly the information researchers from Inserm and the University College London wanted to gather and analyze. They looked at men and women who were between the ages of 45 and 70 at the beginning of the study and tested their memory, vocabulary, reasoning, and verbal fluency three times during a 10-year period.
“The results show that cognitive performance (apart from the vocabulary tests) declines with age and more rapidly so as the individual’s age increases. The decline is significant in each age group,” according to the researchers’ analysis. The participants’ reasoning scores decreased by 3.6% for those men between the ages of 45 and 49, and 9.6% for those between the ages of 65 and 70. Among women, the corresponding figures were 3.6% and 7.4%.
The study’s authors say these findings have significant consequences. “Determining the age at which cognitive decline begins is important since behavioral or pharmacological interventions designed to change cognitive aging trajectories are likely to be more effective if they are applied from the onset of decline,” stated researcher Archana Singh-Manoux.
In other words, if physicians are aware of when problems with memory or speech processing might be likely to start, then they can prescribe effective therapies to address a patient’s specific age-related cognitive problems as early as possible.
“As life expectancy continues to increase,” Singh-Manoux added, “understanding the correlation between cognitive decline and age is one of the challenges of the 21st Century.”
Scientific American’s Christie Nicholson wrote that:
Research shows that active lifestyles, both mentally and physically, slow down brain aging. Scientists thus feel it’s important to know when mental decline typically starts so that people who are getting older — and that’s all of us — can be encouraged to get active sooner rather than later. And have a decent chance to find those car keys.