The statistics on Alzheimer’s disease are overwhelming. More than 5
million Americans are living with Alzheimer’s disease. One in eight
older Americans has the condition, and Alzheimer’s is the sixth leading
cause of death in the United States.
But there is another little-known stat that is equally, if not more,
startling. Among cognitively normal people over the age of 75, about
one-third has sufficient amyloid plaques and neurofibrillary tangles to meet the criteria for Alzheimer’s disease.
These plaques and tangles are especially prominent in those who have
Alzheimer’s and contribute to the degradation of neurons in the brain.
But they also develop in many elderly people, even those who do not have
Alzheimer’s.
It’s these cases — referred to as asymptomatic Alzheimer’s disease
(ASYMAD) — that researchers find particularly fascinating. People with
ASYMAD have all the physical characteristics that could lead to the
progression of Alzheimer’s disease, but have managed to avoid it. If
researchers figure out how, then that could lead the way to better, more
effective prevention and treatment measures for Alzheimer’s, which are
both sorely lacking right now.
Negativity Hurts the Brain
A team of researchers recently hypothesized that certain personality
traits contribute to the cognitive resilience of ASYMAD. They compared
the personality traits of those who subsequently developed clinical
dementia with those who subsequently died cognitively normal, but with
plaques and tangles indicative of Alzheimer’s discovered at autopsy.
And the results of this study may just want to make you turn that
frown upside down, especially if you want to protect your brain.
The subjects in this study were also participants in the Baltimore
Longitudinal Study of Aging, a study of physical and psychological
aging. All agreed to have an autopsy of the brain following their death.
Researchers analyzed data obtained from 111 of the participants who
completed personality tests at least once before the onset of cognitive
decline, and who underwent autopsies after
death.
Personality traits were measured using a 240-item questionnaire that
looked at 30 facets of personality, six for each of the five major
dimensions of personality: neuroticism, extraversion, openness,
conscientiousness and agreeableness.
As for neuropathology, participants were divided into three groups
based on their cognitive health in their last year of life and their
autopsy results:
1. Normal: Patients had no history of cognitive decline and autopsies
showed no amyloid beta plaques or other signs of Alzheimer’s.
2. ASYMAD: Patients had no history of cognitive decline, but the autopsies showed amyloid beta plaques in the brain.
3. AD: Patients received clinical diagnosis of dementia and/or
Alzheimer’s disease while alive, and autopsies revealed amyloid beta
plaques and other signs indicative of Alzheimer’s.
Looking at the results of the autopsies and the personality
questionnaires, researchers discovered that those who had greater
emotional resilience and conscientiousness had lower risk of developing
dementia, even if their autopsies revealed plaques or other signs of
Alzheimer’s.
More specifically, ASYMAD patients scored lower on their personality
questionnaires on negative traits like neuroticism, vulnerability to
stress, anxiety and depression, compared with controls and to those who
actually developed Alzheimer’s disease.
In addition, low scores on conscientiousness were strongly associated with the development of clinical dementia.
Researchers believe those who are more emotionally stable and
conscientious may have greater resilience because they are generally
healthier and engage in behaviors that reduce the risk of dementia —
like exercising and abstaining from tobacco use. In addition,
emotionally stable people tend to have better metabolic and inflammatory
risk profiles and are less likely to have depression — all of which
have been linked to dementia.
Also, they found that personality might be related to the severity of
disease. Specifically, high neuroticism and low agreeableness were
linked to more advanced spread of tangles. And skepticism, cynicism and
being manipulative/deceptive were the characteristics associated with
the most severe amyloid plaques and tangles.
This new knowledge of how personality traits affect the development
of dementia allows us to see just how much of a role attitude plays in
our overall health.
The more negative your overall demeanor, the more it will affect your
health, possibly leading to cognitive decline and Alzheimer’s disease.
Conversely, even if you are at physically high risk of Alzheimer’s,
having a positive attitude toward life could delay or stop the
progression of the disease. All the more reason to spend as much time as
you can smiling, laughing and appreciating all the little things in
your life.
Sources:
Terracciano A et al. Personality and resilience to Alzheimer’s
disease neuropathology: a prospective autopsy study. Neurobiol Aging.
2012 Oct 2. pii: S0197-4580(12)00430-7. doi:
10.1016/j.neurobiolaging.2012.08.008. [Epub ahead of print.]
Saczynski JS et al. Depressive symptoms and the risk of dementia: the Framingham Heart Study. Neurology. 2010 Jul 6;75(1):35-4
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