Are We Diagnosing Dementia All Wrong? Part 1

Hello everybody, you have tuned in to The Truth,

Lies, and Alzheimer's Show with me. I'm Lisa Skinner, your host.

I have a special two-part episode prepared for everybody

today. So, thanks for being here, and thanks for taking time

out of your busy schedule to watch this important

information. I appreciate all of you. So, the topic today for

parts one and part two, which will air a week from two weeks

from Sunday, are we diagnosing dementia? all wrong. This is the

question I'm going to answer in this two-part series, and it's

based on something that was brought to my attention decades

ago. So I was actually made aware of what's called the nun

study of aging and Alzheimer's disease many years ago, and the

findings of this study completely baffled me then, and

they actually still baffled me now. So I did a lot of research

to see if there was any updated information on the findings in

that study, which I will share with you in a minute, and yeah,

I found updated information, so it's much more current than when

the study findings were actually released, and I'm hoping that

what I have discovered will answer some of the more obvious

questions that certainly have lingered with me, and you know,

maybe help with the confusion. So, what the Nunn study is, is

it's an iconic longitudinal study of aging and dementia on a

cohort, a group of 678 Catholic nuns from the School Sisters of

Notre Dame. Now these participants consented to

undergoing annual neuropsychological assessments,

allowing researchers access to convent archives and medical

records after post mortem, or after they passed away, they

donated their brains for study, so highlights of the none study

the uniform lifestyles of the participants, and that's why

they chose the nones. It minimized potential other

influencing factors of the findings of the study. Early

life cognitive ability influence late life cognitive outcomes.

Some of the participants with Alzheimer's disease pathology

did not exhibit dementia. That's one of the things that baffles

me. And then neuropathological comorbidities, in other words,

other medical conditions that they may have had throughout the

study were common and increased their risk of dementia. So, the

beginning in an autopsy study published in 1907 Alois

Alzheimer's first describe the amyloid beta plaques and

neurofibrillary tangles that would come to define Alzheimer's

disease. Then, in 1986 Dr. David Snowden began a pilot study with

these school sisters of Notre Dame to investigate the

relationship between education and age-related disorders. That

was actually his objective. He found out so much more in this

study. The Catholic Sisters of the Congregation, Dr. Snowden

was able to leverage an environment similar to one that

the sisters had shared for most of their adult lives to

carefully examine the lifestyle factors that influenced their

late life physical and cognitive function without many of the

dissimilar factors that plague other similar studies of more

heterogeneous populations, because their lifestyles were so

similar. The results at the start of the study, all

participants were between the age. Of 75 and 102 years old,

the average being 83 years old, and all had similar backgrounds.

All of them were born before 1917 All of them joined the

school around the same time. Their communal living

arrangements provided all the sisters with the same or similar

housing, income, nutrition, and access to health care.

Furthermore, members of the school had similar reproductive

and marital histories, social and support networks, smoking

history, and alcohol intake, these are all important factors

in getting the most accurate results of studies like this.

You don't have to factor out all the dissimilarities between the

the people that are participating in these types of

studies, the education of the nun study participants ranged

from grade school to having doctorate degrees, but 85%

attained at least a bachelor's degree, and 89% of the nuns were

teachers at some point in their careers, about 678 of the total

participants. Now, the participants were also

predominantly Caucasian, and there were no significant

differences found between participants and

non-participants of the school's organization in demographic

data, including country of birth, age, race, or annual

mortality rate, writing, emotions, lifestyle, and

cognition were one of the major findings from this nun study,

and how the participants' lifestyle and education may

actually deter Alzheimer's symptoms.

Participants who had an education level of a bachelor's

degree or higher were less likely to develop Alzheimer's

disease later in life. They also lived longer than some of their

colleagues who did not have at least a bachelor's degree

education. Furthermore, the participants' word choice and

vocabulary also correlated to the development of Alzheimer's

disease, and among the documents reviewed were autobiographical

essays that were written by the nuns upon joining the

sisterhood, and then upon review it was found that an essay's

lack of linguistic density, that's the term they use, for

example, the complexity of the used the words they used in

their writings, the vivacity, the fluency - these all actually

functioned as a significant predictor of its author's risk

for developing Alzheimer's disease in an in their older

years. Now the study also found that the sisters who wrote

positively in their personal journals were much more likely

to live longer than their counterparts. Three indicators

of long life were found when coding the sisters'

autobiographies, they were the number of positive sentences,

the number of positive words, and the variety of positive

emotions that they conveyed and used. The less positivity in

writing ended up correlating with greater mortality. Well,

there were many variables in this study that was unable to

glean from their autobiographies of the sisters, such as

long-term hopefulness or bleakness in one's personality,

their optimism towards life, their pessimism, their

ambitions, and other variables. And then the average age of the

nuns who began writing their autobiographies was 22 years

old. Now some of the participants who used more

advanced words in their autobiographies had less

symptoms of Alzheimer's in their older years. Roughly 80% of the

nuns whose writing was measured as lacking in linguistic density

did go on to develop Alzheimer's disease in their older years,

and meanwhile of those. Whose writing was not lacking, only

10% later developed the disease. This was found when researchers

examined neuropathology after the nuns passed away, confirming

that most of those who had a low idea density did have

Alzheimer's disease, and most of those with high density did not.

Snowden found that exercise was inversely correlated with

development of Alzheimer's disease. We've talked about on

many of Truth, Lies, and Alzheimer's episodes showing

that participants who engaged in some sort of daily exercise were

more likely to retain their cognitive abilities during their

aging process. Participants who started exercising later in life

were more likely to retain cognitive abilities even if they

had not exercised before, that's optimistic and very encouraging.

So conclusions and further research now overall in these

findings of the Nunn study, it indicated multiple factors

concerning expression of Alzheimer's traits. The data

primarily stated that age and disease do not always guarantee

impaired cognitive ability, and that traits in early, mid, and

later life do have strong relationships with the risk of

Alzheimer's disease, as well as the mental and cognitive

disabilities of old age. Another finding is that in postmortem

MRI research, they have also used the autopsy data to

determine that there is a relationship. Now, I found this

really amazing. There is a relationship between the number

of teeth that an individual has at death with how likely they

were to have had dementia. Those with fewer teeth were more

likely to have dementia while they were living, and because,

and also a lot of them who were showing no signs of dementia,

but may have had plaques and tangles that were definitely in

their brains upon autopsy had built up a much stronger

cognitive reserve due to their educational level, so the study

proved that the brain can exhibit severe physical signs of

Alzheimer's disease, such as plaques and tangles, without the

individual ever displaying dementia symptoms. High

education and active mental engagement build reserve. We

also call this neuroplasticity, early linguistic ability. So the

researchers analyzed the autobiographical essays that the

nuns wrote in their youth around 17 to 22 years old, they found

that those with the idea density and grammatical complexity in

early adulthood were strongly linked to a lower risk of

developing Alzheimer's disease decades later. In terms of

vascular health, the postmortem results, or after-death results,

revealed that small, often clinically silent strokes that

some of them were experiencing in life dramatically compounded

the damage of Alzheimer's disease, making vascular health,

which is controlling blood pressure and preventing obesity,

a major factor in staving off dementia.

The non nuns who expressed more positive emotions and had higher

levels of optimism in their early life. The writings tended

to live significantly longer. So, the nun study fundamentally

changed how the medical community views Alzheimer's by

highlighting that the disease does have roots stretching all

the way back to early life education and linguistic habits.

It sparked global research into building cognitive. Reserve and

maintaining blood vessel health as ways to protect the aging

brain. So, here are the key findings about memory and aging.

Many of the nuns remained mentally sharp well into old

age, even as their body showed aging signs, the cognitive

decline varied widely among the sisters. Some stayed mentally

alert much longer than average. The role of early life factors

showed that people who had higher early life education and

verbal ability tended to show better memory and thinking

skills, also later in their lives. Also, a strong vocabulary

and reading level in youth were linked to clearer thinking in

their older age, that brain health and in the aging process,

where some brains showed Alzheimer's type changes again

upon autopsy, they found plaques and tangles in some of the

sisters who had not shown any symptoms of dementia from

Alzheimer's disease, or what are the other brain diseases that

causes dementia, and conversely, some of the nuns, they didn't

find any plaques and tangles, but they were symptomatic and

showed mild to severe signs of Alzheimer's disease and related

dementia, so without any corresponding memory problems

during their life, and this suggests that other factors

definitely influence whether those changes affect thinking

again. Other showed no plaques and tangles, and many did

display a variety of cognitive decline to some degree. So, the

study highlighted that brain aging is not determined by brain

changes alone. How one's brain organizes and uses information

also matters in terms of health and lifestyle clues. Physical

health, good social networks, and engaging mental activities

were associated with better cognitive aging, a habit of

lifelong learning and staying socially active appear

protective for thinking skills. So, what really does this mean

in simple terms? And it's very consistent with what research

has shown us, and I talk about it often in these episodes that

being mentally engaged, educated early on, and socially connected

can help you stay sharper as you age, even if your brain shows

some typical aging changes. Brain changes link to aging or

diseases don't always predict how well someone thinks or

remembers later. Lifestyles and lifelong habits play a huge

role. And then finally, here is a recently updated summary of

the key ideas that were shown about amyloid plaques, tau

tangles, and what current research is now saying about

Alzheimer's disease. One of the questions that the scientific

community is still trying to figure out, what are the main

brain changes in Alzheimer's disease. Well, they think that

the two biggest clues that they are looking for are amyloid

plaques and tau tangles. These amyloid plaques are sticky bits

that build up outside the brain cells, and the tau tangles are

twisted fibers that form inside the brain, and together with

nerve cell damage and brain cell death, these changes lead to

memory problems and trouble thinking. Another question, do

plaques actually cause Alzheimer's disease? Well, the

answer is, it's still complicated in people with

certain genetic forms of the disease. Amyloid plaques seem to

start the process in most people who get Alzheimer's disease

later in life. Plaques are a risk factor and may help kick.

Things off, but they don't explain everything, and that is

why the results of the nun study was so baffling. Why would some

have plaques and tangles and no symptoms, and vice versa? Now

the tau tangles tend to line up more closely with how bad the

symptoms are as the disease progresses, so many researchers

think Alzheimer's is not caused by one thing alone, but by

several factors working together. Question, what does

current research say about amyloid plaques, and the answer

is that these plaques often appear before symptoms even

begin to show and raise the risk of developing dementia. Some

studies suggest that smaller, soluble forms of amyloid are

especially harmful to brain connections and thinking, as

well as many of the older people have plaques, but don't show

symptoms of dementia or never develop it at all, which means

that plaques are not the whole story. What about tau tangles?

Well, tau tangles are more tightly linked to how severe

memory and thinking problems are, especially as the disease

advances. The tau seems to spread through the brain in a

pattern that follows connected brain networks. So researchers

are testing therapies aimed at stopping tau from spreading, and

so, how are doctors diagnosing and treating it now? Diagnosis,

current diagnosis, we are now able to use biomarkers like

tests in spinal fluid or blood tests, and in more sophisticated

brain scans that detect plaques and or tangles, or both, to

identify the disease earlier and track its progression.

Treatments that remove or neutralize amyloid have shown

mixed results. They may help some people if started early.

So, treatments targeting tau, inflammation, and blood vessel

health are also being studied, often in combination with

anti-amyloid approaches. The big idea is to start treatment early

and tailor it to each individual person's biology and applied

risk factors, and so that wraps up part one of our we diagnosing

dementia all wrong. So we will be airing part two in about two

weeks, so hopefully you'll catch both episodes, because this is

really, really important information, and it's, it's kind

of like a breakthrough now in what we believe and what we

understand about what causes Alzheimer's disease, and we can

thank the Nunn Study for kind of, you know, setting the tone

for realizing that it's not what we may have originally thought.

So we'll see you next week for this episode, and then in two

weeks for part two of Are We Diagnosing Dementia All Wrong.

I'm Lisa Skinner, your host of The Truth, Lies, and Alzheimer's

Show. And hope you all have a great rest of your week, and

I'll see you next time. Bye bye.