Cognitive Decline Begins in Mid-Life9 years ago
Posted on Jan 19, 2012, 6 a.m.
Large-scale prospective study reveals that on all cognitive measures except vocabulary, linear declines start as early as age 45.
Whereas global life expectancy is on the rise, the maintenance of cognitive health becomes a public health priority, since poor cognitive status is considered a major disabling condition in old age. Previous studies have established an inverse association between age and cognitive performance, with most studies suggesting little cognitive decline occurs before the age of 60. Archana Singh-Manoux, from Inserm (France), and colleagues completed a large-scale prospective study conducted over a 10-year period, utilizing data from the Whitehall II cohort study involving 10,308 men and women, ages 45 to 70 years the start of the study. Over the 10-year study time frame, each subject was evaluated for memory, vocabulary, reasoning and verbal fluency on three separate occasions. The results showed 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. For example, during the period studied, reasoning scores decreased by 3.6 % for men aged between 45 and 49, and 9.6 % for those aged between 65 and 70. The corresponding figures for women stood at 3.6% and 7.4% respectively. The study authors conclude that: "Cognitive decline is already evident in middle age (age 45-49).”
Archana Singh-Manoux, Mika Kivimaki, M Maria Glymour, Alexis Elbaz, Claudine Berr, Klaus P Ebmeier, et al. “Timing of onset of cognitive decline: results from Whitehall II prospective cohort study.” BMJ 2012;344:d7622, 5 January 2012.