Exploring links between hearing loss, dementia and the ‘cognitive reserve’ — plus the role of hearing aids

How does your hear­ing affect demen­tia risk? (Alzheimer’s Research UK):

With around 1 mil­lion peo­ple affect­ed by demen­tia in the UK, and 12 mil­lion peo­ple esti­mat­ed to have a type of hear­ing loss, it’s nev­er been more impor­tant to under­stand this link.

One way that hear­ing loss and demen­tia could be linked is through our blood system.

Cer­tain types of demen­tia, par­tic­u­lar­ly vas­cu­lar demen­tia, are caused when there is less blood flow reach­ing the brain. This can dam­age our brain cells. Recent stud­ies have also shown that the parts of our brain that process sounds (our audi­to­ry sys­tem) have many blood ves­sels and are vul­ner­a­ble to damage.

Dr Nico­las Michal­s­ki is work­ing to under­stand this link at Insti­tut Pas­teur in France, thanks to fund­ing from Alzheimer’s Research UK. He’s inves­ti­gat­ing how changes in the blood sup­ply to the brain is linked to hear­ing prob­lems and in turn, whether this could dementia…

Anoth­er area of research is look­ing at whether hear­ing loss indi­rect­ly affects demen­tia risk by mak­ing it hard­er for peo­ple to stay con­nect­ed. Social iso­la­tion is anoth­er known risk fac­tor for dementia.

We know that reg­u­lar men­tal activ­i­ty and social con­nec­tion can help to build a person’s ‘cog­ni­tive reserve’. This is the brain’s abil­i­ty to cope when it’s faced with chal­lenges, like disease.

News in Context:

Study: Hear­ing aids may help old­er adults delay demen­tia, depres­sion, anx­i­ety, and falls:

“Old­er adults who get a hear­ing aid for a new­ly diag­nosed hear­ing loss have a low­er risk of being diag­nosed with demen­tia, depres­sion or anx­i­ety in the fol­low­ing three years, and a low­er risk of suf­fer­ing fall-relat­ed injuries, than those who leave their hear­ing loss uncor­rect­ed, a new study finds.

Hear­ing aids, by reduc­ing cog­ni­tive load, can improve brain func­tion in per­sons with hear­ing loss:

“Most peo­ple will expe­ri­ence hear­ing loss in their life­time … Think about some­body who is still work­ing and they’re not wear­ing hear­ing aids and they are spend­ing so much of their brain­pow­er just try­ing to focus on lis­ten­ing. They may not be able to per­form their job as well. Or if they can, they’re exhaust­ed because they are work­ing so much hard­er. They are more tired at the end of the day and it’s a lot more tax­ing. It affects their qual­i­ty of life.”

35% of world­wide demen­tia cas­es could be pre­vent­ed by mod­i­fy­ing these 9 mod­i­fi­able risk fac­tors. The nine mod­i­fi­able risk fac­tors include:

Ear­ly life — Edu­ca­tion to a max­i­mum of age 15

Mid-life — Hyper­ten­sion; Obe­si­ty; Hear­ing loss

Lat­er life — Depres­sion; Dia­betes; Phys­i­cal inac­tiv­i­ty; Smok­ing; Low social contact