How to Reduce Your Risk of Alzheimer’s Dementia

Stress and anxiety have been linked to possible risk of dementia for a number of
years now. Animal and some human studies have examined brain areas affected
by chronic anxiety, fear and stress, using neuroimaging and stress and fear
conditioning with animals. We now know that there is a “see-saw” relationship
between the amygdala and the prefrontal cortex (PFC) in which an overactive
amygdala (due to fear, anxiety and chronic stress), is associated with an
underactive PFC (thinking areas of the brain that regulate emotional responses).
Further, chronic stress can cause the hippocampus to atrophy. Since that brain
area is important to long-term memory there is an obvious relationship with
dementia and chronic stress.

While this relationship has been known, clinical practice has not placed much
focus on preventing chronic stress in order to reduce the risk of dementia. An
October 2020 presentation by Dr. David Bennett at the National Academy of
Neuropsychology (NAN) may change that. Dr. Bennett is the Director of Rush
Alzheimer’s Disease Center at Rusk University Medical Center in Chicago. Dr.
Bennett spoke about early results of 2 very important longitudinal studies
involving participants of religious orders, called the Religious Orders Study and
the Rush Memory and Aging Project. The Religious Orders Study participants are
1500 older nuns, priests, and brothers without known dementia from across the
US who have agreed to annual clinical evaluation and to brain donation. The
project began in 1993; approximately 375 have developed dementia. Over 600
have developed MCI and over 825 brain autopsies have been performed to date.
The Rush Memory and Aging Project began in 1997 and include 2,200 residents
from the Chicago area who agreed to annual clinical evaluation and to donate
their bodies on death. Of that group to date, 375 developed dementia, 625 have
MCI and 925 autopsies have been performed.

Findings from 2 such large studies are immense and will be coming forward for
many years; however, Dr. Bennett’s talk provided a glimpse into prevention that
neatly fits the subject matter of this column. There is a continuum of cognitive
aging from cognitive decline to MCI to dementia. The brain pathology that relates
to changes in cognition are increasingly clear as the research continues around
the world. However, the Rush studies have made a discovery that will allow
people to better maintain cognitive health in old age.

Much of late life cognitive decline is not due to common neurodegenerative
pathologies (brain atrophy, infarctions, NP, NFT, NIA-Reagan, PHFtau temp, and
amyloid, etc.); only 41 % of the variance is explained. In other words, most brains
of elderly people show common neurodegenerative pathologies even though they
do not always have the same degree of cognitive decline (MCI to dementia). The
question became what else contributes to cognitive decline? All participants
were adjusted for age at baseline and for sex. The following variables were
studied: education, early life instruction in foreign language and music, emotional
neglect in childhood, depression, purpose in life, social isolation, social activity,
social networks (number of children, relatives, friends they saw each month and
felt close enough to talk about private matters or call upon for help), tendency to
avoid harm, avoid new situations, chronic distress, anxiety, size of one’s life
space (from 1 bedroom to travel outside of town), and diet. Those that stood out
as lowering the risk of dementia are well summed up in Dr. Bennett’s final
recommendations on how to build a better brain as we age. (Bennett DA.
Scientific American. Special Collector’s Edition. 2017; Summer: 85-91.)

1. Pick your parents well! Make sure you get good genes, a good education, a
   second language and music lessons. Avoid emotional neglect.
2. Engage in regular cognitive and physical activity.
3. Strengthen and maintain social ties.
4. Get out and explore new things.
5. Chillax and be happy.
6. Avoid people who are downers, especially close family members!
7. Be conscientious and diligent.
8. Spend time engaged in activities that are meaningful and goal-directed.
9. Be heart-healthy: what’s good for the heart is good for the brain.
10. Eat a MIND diet, (Mediterranean-DASH Intervention for Neurodegenerative
    Delay diet) with fresh fruit and vegetables and fish.
11. Be lucky!