[A version of this item appears in: Dementia: the Latest Evidence Newsletter (RWHT), Volume 2 Issue 6, January 2012].
Research at University College London indicates that the brain starts to deteriorate as early as 45 years of age. Researchers assessed the memory, vocabulary and comprehension skills of 5,198 men and 2,192 women (who were all UK civil servants) aged between 45 and 70, over 10 years. They discovered a 3.6% decline in mental reasoning in women and men aged 45-49.
Previous research had suggested that significant cognitive decline does not begin before the age of 60, but this study shows that it often begins in middle age. Cognitive scores were found to decline in all areas of mental ability except vocabulary, and there was a faster decline in older people. There was a 9.6% decline in mental reasoning in men aged 65-70 and a 7.4% decline for women of the same age. Men and women aged 45-49 showed a 3.6% decline.
This has more than just academic significance, because dementia treatments and preventative life-style choices are more likely to be effective if started during the earlier stages of mental impairment. Regarding some of the modifiable risk factors for dementia, such as obesity, hypertension, and hypercholesterolaemia, it may be that the mid-life levels are more important than those occurring at older ages.
Brain function can start declining ‘as early as age 45’. London: BBC Health News, January 6th 2012.
Singh-Manoux, A. Kivimaki, M. [and] Glymour, MM. [et al] (2012). Timing of onset of cognitive decline: results from Whitehall II prospective cohort study. BMJ January 5th 2012; 344: d7622.
Do our brains decline from middle age? London: NHS Choices, January 6th 2012.