Are We Diagnosing Dementia All Wrong? Part 1 | What the Nun Study Revealed About Alzheimer’s

Are you caring for a loved one with dementia? You don't have to figure this out all on your own. Welcome to Truth, Lies Alzheimer's, the show that helps you reimagine a new relationship with your loved one, a relationship a little more free of stress and anxiety. Join host Lisa Skinner and her 30+ years of experience as she guides you on a new path to a better relationship with those you care for. Here's Lisa.

Hello everybody, you have tuned in to the Truth, Lies 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 schedules to watch this important information. I appreciate all of you. So the topic today for Parts 1 and Part 2, which will air a week from— 2 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 baffle 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, uh, 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 Nun 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 postmortem, or after they passed away. They donated their brains for study. So highlights of the Nun Study: the uniform lifestyles of the participants, and that's why they chose the nuns. It minimized potential other influencing factors of the findings of the study. Early life cognitive ability influenced late life cognitive outcome. Comes, 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 first described 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 ages of 75 and 102 years old, the average being 83 years old, and all had similar backgrounds. All of 'em were born before 1917. All of 'em 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 healthcare. 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 range 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 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 use of the words they used in their writings, the vivacity, the fluency, these all actually functioned as a significant predictor of its authors' risk for developing Alzheimer's disease in, 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. While 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 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 Nun 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 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 bodies 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 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 one of 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, others 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 appeared 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 linked 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 1 of Are We Diagnosing Dementia All Wrong? So we will be airing part 2 in about 2 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 Nun 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 2 weeks for part 2 of Are We Diagnosing Dementia All Wrong? I'm Lisa Skinner, your host. Of the Truth, Lies Alzheimer's show, and hope you all have a great rest of your week, and I'll see you next time. Bye-bye.

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