1. Health
You can opt-out at any time. Please refer to our privacy policy for contact information.

Life Expectancy in Alzheimer's Disease and Dementia

Gender, Age, Care and Longevity

By

Updated July 11, 2014

Alzheimer's disease and other illness involving dementia are considered understudied. There are 24 million people in the world with Alzheimer's disease or other forms of dementia, and this number is growing rapidly. This number is expected to triple to 81 million by 2040.

Alzheimer’s Disease, Dementia and Life Expectancy

Researchers followed 13,000 people over the age of 65 from 1991 to 2005 to better understand diseases of dementia. Over that time, 438 people in the study developed Alzheimer's disease or another form of dementia. 81% of those developing dementia died before the study was completed.

Age and Gender Main Factors for Alzheimer’s Disease and Dementia Longevity

The main factors that determined how long a person in the study lived after being diagnosed with Alzheimer's disease or another form of dementia were age, gender and level of disability. Here are the main findings:
  • Women lived an average of 4.6 years after diagnosis, men lived 4.1 years.
  • People diagnosed when under age 70 lived 10.7 years compared to 3.8 years for people over 90 when diagnosed.
  • Patients who were frail at the time of diagnosis did not live as long, even after adjusting for age.
  • Overall, the average survival time for someone in the study diagnosed with Alzheimer's disease or dementia was 4.5 years.

Why Do Alzheimer’s Disease and Dementia Shorten Life?

The average 65-year-old can expect to live 18.5 years longer – almost double the amount after being diagnosed with Alzheimer’s disease or dementia. The study did not examine the reasons for this shorter life expectancy. In the group that was diagnosed after age 90, one would expect shorter life expectancies simply due to their advanced age. The loss of life expectancy in the younger group could be attributed to lifestyle changes casused by dementia such as no longer exercising or eating well, but that doesn’t explain everything. It could also be that early onset Alzheimer’s disease and dementia take a different course than the later onset types. So, from the research, we know the average life expectancies, but we don’t know why.

How To Help Someone With Dementia

While you can't change factors such as age at diagnosis or gender, the study did show that the level of care that a person receives impacts life expectancy. Be sure that you explore options when it comes to creating a care plan for a loved one diagnosed with Alzheimer's disease and take advantage of any support groups or other resources that may help.

Preventing Alzheimer’s Disease and Dementia

There have been many studies looking into the use of puzzles and other forms of “mental fitness” to help delay or prevent Alzheimer’s disease and dementia. A famous study of nuns showed that the individuals most curious and engaged mentally in the world had less Alzheimer’s disease and dementia. Try these top ways to exercise your brain.

Source:

Xie J, Brayne C, Matthews FE; and the Medical Research Council Cognitive Function and Ageing Study collaborators. Survival times in people with dementia: analysis from population based cohort study with 14 year follow-up. BMJ. 2008 Jan 10.

©2014 About.com. All rights reserved.

We comply with the HONcode standard
for trustworthy health
information: verify here.