Dementia rates in the U.S. falling: higher education one cause

Dementia is known as an almost inevitable disease of ageing. However a study published this week in JAMA Internal Medicine has found that dementia rates in the United States have reduced. (1) One reason for this, say the researchers, is down to education.

The team found that education exposure may slow down the onset of dementia, with the study finding that the prevalence of dementia dropped from 11.6% to 8.8% from 2000 to 2012 in those studied. These findings are very welcome in an ageing population.

Link between 'higher level' of education and 'cognitive reserve'?

The study examined over 21,000 adults over 65 and compared the onset of dementia with time spent in education. Adjustments were made for the level of individual risk of developing dementia posed by risk factors such as cardiovascular disease and diabetes. It was found that those who spent more years in education were significantly less likely to have developed dementia. The study also linked a general increase in education with protection overall.

It has been suggested that this 'higher level' of education leads to a larger 'cognitive reserve', where earlier exposure to learning creates more and stronger brain connections.

As the process of dementia progresses, it takes longer for a significant effect on brain structure to manifest as an impairment. The brain is more robust to change and can cope better with losing function but still working over all. Essentially the brain was able to weather more damage and stay standing.

The study did not conclude that dementia itself can be prevented totally, but delayed and the rate of progression slowed. The study reflects the conclusions of multiple studies over recent years, including those in the UK. (3)

Silent factors in dementia protection

The authors of the study did remark that although all efforts were made to account for the role of pre-existent risk factors, not all social and behavioural variation could be accounted for in their conclusions. There may be silent extra factors involved in protecting against dementia, but the study showed strong evidence for the individual role of education. The study suggests that early life education is indeed protective in at least delaying dementia.

Dementia risks and types

Dementia is the name given to a group of 'degenerative' diseases affecting the brain. The most well-known type is Alzheimer's disease, where abnormal levels of deposits of bodily protein cause local inflammation and brain destruction. Vascular dementia is the result of small clots in the brain adding up over the years. Other dementia types include dementia with Lewy bodies. The connecting theme between all of them is progressive brain destruction and co-existent cognitive impairment.

An individual's risk of disease increases with age, blood pressure, diabetes and a positive family history. The end result is usually fatal if given enough time.Given our ageing population, dementia is set to become a significant concern for both people affected by it and their loved ones.


Any opinions above are the author's alone and may not represent those of the NHS. Any comment is based on the best available evidence at the time of writing. All data is based on externally validated studies unless expressed otherwise. Novel data is representative of sample surveyed. Online recommendation is no substitute for seeing your own doctor and should not be taken as medical advice.

Sources

1) Langa KM et al (2016) A comparison of the Prevalence of dementia in the United States in 2000 and 2012 Jama epub 21/11/2016

2) http://www.npr.org/sections/health-shots/2016/11/21/502872563/dementia-risk-declines-and-education-may-be-one-reason-why

3) https://www.theguardian.com/society/2016/apr/19/drop-in-dementia-rates-suggests-disease-can-be-prevented-researchers-say

4) Simon, C et al (2016) 'Oxford Handbook of General Practice' 4th Edition, Oxford University Press, Oxford

5) Lindsay KW et al, (1993) 'Neurology and Neurosurgery Illustrated' 2nd Edition, Churchill Livingstone, London