Nav: Home

Elderly may face increased dementia risk after a disaster

October 24, 2016

Boston, MA - Elderly people who were uprooted from damaged or destroyed homes and who lost touch with their neighbors after the 2011 tsunami in Japan were more likely to experience increased symptoms of dementia than those who were able to stay in their homes, according to a new study from Harvard T.H. Chan School of Public Health. The study was the first to look at dementia as a potential health risk in the aftermath of a disaster.

The study will appear online October 24, 2016 in an Early Edition of the Proceedings of the National Academy of Sciences journal (PNAS).

"In the aftermath of disasters, most people focus on mental health issues like PTSD," said Hiroyuki Hikichi, research fellow at Harvard Chan School and lead author of the study. "But our study suggests that cognitive decline is also an important issue. It appears that relocation to a temporary shelter after a disaster may have the unintended effect of separating people not just from their homes but from their neighbors--and both may speed up cognitive decline among vulnerable people."

The Harvard Chan researchers, working with colleagues in Japan, were able to conduct a "natural experiment" among a group of elderly residents of the coastal city of Iwanuma, located about 80 kilometers west of the earthquake epicenter, where nearly half the land area was inundated by the tsunami. Seven months before the disaster, elderly residents of Iwanuma had been surveyed about their health as part of an ongoing study of aging called the Japan Gerontological Evaluation Study (JAGES). Two-and-a-half years after the tsunami, the researchers conducted a follow-up survey among the same group.

Out of 3,566 survivors of the tsunami disaster aged 65 or older--some who were able to remain in their homes and some who were forced out--38.0% said they lost relatives and/or friends and 58.9% reported property damage. In the pre-tsunami survey, 4.1% of respondents had been assessed with dementia symptoms; after the tsunami, the percentage jumped to 11.5%. The prevalence of stroke increased, from 2.8% to 6.5%, as did the prevalence of hypertension (54.0% to 57.2%). The percentage of people who reported not interacting with their neighbors--not even with greetings--nearly doubled, from 1.5% to 2.9%.

Those who wound up in temporary housing after their houses were either destroyed or sustained major damage had the highest levels of cognitive decline. There was a strong dose-response association: People whose houses were more severely damaged experienced more cognitive decline. Depression and declines in informal social interactions with friends and neighbors appeared to play a role in the link.

By contrast, loss of relatives and/or friends did not seem to impact cognitive abilities.
-end-
Other Harvard Chan School authors included S V Subramanian and Ichiro Kawachi, senior author of the study.

Funding for the study came from the National Institutes of Health (R01 AG042463); Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (KAKENHI 23243070, KAKENHI 22390400, and KAKENHI 24390469); a Health Labour Sciences Research Grant from the Japanese Ministry of Health, Labour and Welfare (H24-Choju-Wakate-009); and a grant from the Strategic Research Foundation Grant-Aided Project for Private Universities from the Japanese Ministry of Education, Culture, Sports, Science and Technology (S0991035).

"Increased risk of dementia in the aftermath of the 2011 Great East Japan Earthquake and Tsunami," Hiroyuki Hikichi, Jun Aida, Katsunori Kondo, Toru Tsuboya, Yusuke Matsuyama, S.V. Subramanian, and Ichiro Kawachi, PNAS, online October 24, 2016, doi: 10.1073/pnas.1607793113

Visit the Harvard Chan School website for the latest news, press releases, and multimedia offerings.

Harvard T.H. Chan School of Public Health brings together dedicated experts from many disciplines to educate new generations of global health leaders and produce powerful ideas that improve the lives and health of people everywhere. As a community of leading scientists, educators, and students, we work together to take innovative ideas from the laboratory to people's lives--not only making scientific breakthroughs, but also working to change individual behaviors, public policies, and health care practices. Each year, more than 400 faculty members at Harvard Chan School teach 1,000-plus full-time students from around the world and train thousands more through online and executive education courses. Founded in 1913 as the Harvard-MIT School of Health Officers, the School is recognized as America's oldest professional training program in public health.

Harvard T.H. Chan School of Public Health

Related Dementia Articles:

Flies the key to studying the causes of dementia
A research team from the University of Plymouth, University of Southampton and the Alexander Fleming Biomedical Sciences Research Center, Vari, Greece, have studied two structurally-similar proteins in the adult brain and have found that they play distinct roles in the development of dementia.
Stroke prevention may also reduce dementia
Ontario's stroke prevention strategy appears to have had an unexpected, beneficial side effect: a reduction also in the incidence of dementia among older seniors.
Dementia: The right to rehabilitation
Rehabilitation is important for people with dementia as it is for people with physical disabilities, according to a leading dementia expert.
One in 4 elderly Australian women have dementia
At least a quarter of Australian women over 70 will develop dementia according to University of Queensland researchers.
Rural dementia -- we need to talk
Research carried out by Plymouth University into the experience of dementia in farming and farming families, and its impact on their businesses and home lives, has identified four areas of concern which need to be addressed if dementia in the countryside is to be managed.
Women with dementia receive less medical attention
Women with dementia have fewer visits to the GP, receive less health monitoring and take more potentially harmful medication than men with dementia, new UCL research reveals.
Dementia on the downslide, especially among people with more education
In a hopeful sign for the health of the nation's brains, the percentage of American seniors with dementia is dropping, a new study finds.
New study suggests rethink of dementia causes
University of Adelaide researchers have developed a new theory for the causes of dementia and other neurodegenerative diseases, involving an out-of-control immune system.
Bleeding stroke associated with onset of dementia
Bleeding within the brain, or intracerebral hemorrhage, was associated with a high risk of developing dementia post stroke, according to research presented at the American Stroke Association's International Stroke Conference 2016.
Dementia: New insights into causes of loss of orientation
The University of Exeter Medical School led two studies, each of which moves us a step closer to understanding the onset of dementia, and potentially to paving the way for future therapies.

Related Dementia Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Bias And Perception
How does bias distort our thinking, our listening, our beliefs... and even our search results? How can we fight it? This hour, TED speakers explore ideas about the unconscious biases that shape us. Guests include writer and broadcaster Yassmin Abdel-Magied, climatologist J. Marshall Shepherd, journalist Andreas Ekström, and experimental psychologist Tony Salvador.
Now Playing: Science for the People

#514 Arctic Energy (Rebroadcast)
This week we're looking at how alternative energy works in the arctic. We speak to Louie Azzolini and Linda Todd from the Arctic Energy Alliance, a non-profit helping communities reduce their energy usage and transition to more affordable and sustainable forms of energy. And the lessons they're learning along the way can help those of us further south.