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Researchers in the Netherlands have found individuals whose brains showed signs of Alzheimer’s disease but who showed no symptoms while alive in a national brain bank.
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Some experts say this is a rare occurrence, but it can happen because the disease can take decades between the first amyloid deposits and symptoms of the disease.
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So-called resistance to Alzheimer’s symptoms can develop due to genetics or lifestyle factors, but some research suggests that cognitive-enhancement activities can help moderate those symptoms.
Researchers in the Netherlands recently made a surprising discovery after studying data from more than 2,000 brains at the Netherlands Brain Bank.
Their study – appears in Acta Neuropathologica Communications – He found that a subgroup of people had clear symptoms Dementia In the brain tissue, but they did not show any symptoms while alive.
Of course, they only identified 12 of these individuals from the brain tissue with the relevant clinical data. But it raised many questions about the disease itself and what makes a person able to cope with the disease.
Dementia directly affects more than that. 55 million people Globally, up to 70% of people have Alzheimer’s disease, which is characterized by the loss of brain cells associated with the toxic accumulation of two proteins. Amyloid And Yes.
The most common symptoms of Alzheimer’s disease are: memory loss, cognitive deficits, problems with speech, recognition, spatial awareness, reading or writing, and behavioral and behavioral changes.
As Alzheimer’s progresses slowly, these symptoms are mild at first and gradually worsen.
What causes Alzheimer’s symptoms to appear?
The occurrence of Alzheimer’s disease without symptoms is called “resilience.”
In the reverse group, researchers observed a type of brain cells called astrocytes – which they described in a. press release It appears to produce more of an antioxidant called metallothionein, which acts as “garbage collectors” in the brain.
Astrocytes can increase inflammation when they interact with microglia in the brain, but those pathways linked to Alzheimer’s appeared to be less active in the resistant group.
Researchers found that the brain cell response, which is supposed to remove any misfolded toxic proteins, was normal in the relatively stable group.
This so-called “unfolded protein response” is common in Alzheimer’s patients. And there were indications that the brain cells of the resilient individuals had more mitochondria than the cells of other Alzheimer’s patients, meaning that the power generation would have been stronger in the resilient group.
Cognitive reserve and the phenomenon of ‘resistance’
Genetics and lifestyle may play a role in this type of resistance; David Merrill, MD, Ph.Dgeriatric psychiatrist and director of the Pacific Neuroscience Institute’s Pacific Brain Health Center at Providence St. John’s Health Center in Santa Monica, CA, who was not involved in the study; Medical News Today.
“A collection of knowledge, which is the ability to withstand brain damage, plays a significant role. In addition, genetic factors, lifestyle and environmental factors can modulate the onset and severity of the disease despite the presence of symptoms,” Merrill said.
“The authors talk about changes in the function of neurons, such as astrocytes and microglia, or changes in energy-generating components of neurons, such as mitochondria,” he said.
Yuko Hara, Ph.DDirector of Aging and Alzheimer’s Prevention at the Alzheimer’s Drug Discovery Foundation (ADDF), who was not involved in the study; MNT There can be a delay of 20 to 30 years between the first signs of amyloid deposition in the brain and the symptoms.
There are ways people can develop their cognitive repertoire over time, Hara explains.
“Cognitive reserve is the brain’s ability to withstand age-related changes or the effects of diseases such as beta-amyloid, which would normally reduce cognitive function. Based on this phenomenon, the knowledge and experience people gain over a lifetime can help them better manage diseases like beta-amyloid.” There are many things you can do to increase your cognitive capacity: take classes to learn something new, read books, learn a new language, learn how to play a musical instrument, or test your brain in other ways. take on.
How common is Alzheimer’s without symptoms?
Merrill said people or spouses with Alzheimer’s disease may present for screening without symptoms, but in general, most clinic patients seek care when symptoms develop.
He explained: “It is not uncommon to have patients with Alzheimer’s disease or any other disease without symptoms. That said, the first signs [Alzheimer’s] It can mimic normal aging, so many individuals answer the question: Is what is happening normal or just beginning? [Alzheimer’s disease]?
“Rather than a single symptom event, we see a series of symptoms. In this way, it makes sense that brain donors rarely showed up without symptoms in the study, Merrill added.
“Alzheimer’s pathology is seen in asymptomatic individuals, although this is not the norm in clinical practice. It is consistent with new research showing that Alzheimer’s disease can exist without overt cognitive symptoms, possibly due to cognitive accumulation or compensatory mechanisms in the brain reported in the study.
– David Merrill, MD, Ph.D
Hara said Alzheimer’s symptoms can start early in life without the usual symptoms. She points to several interesting studies of the phenomenon.
“There are many people who have symptoms of Alzheimer’s disease without symptoms of Alzheimer’s. Beta-amyloid, a hallmark of Alzheimer’s disease, can begin to build up in the brain. Just in the 20sShe said.
“Amyloid deposition in the brain begins decades before Alzheimer’s symptoms begin. One study found that 44% of 90-year-olds have good cognitive function. He had amyloid pathologyHara said.
“There are also examples of genetic mutations that protect against Alzheimer’s disease,” she added.
However, she explained that these are rare occurrences.
“A From the 2019 study Earlier, a woman who carried a mutation in presenilin 1 (PSEN1), the genetic cause of Alzheimer’s disease, did not develop dementia in her 40s, as did other mutations. Instead, she had mild memory loss in her 70s. Researchers have confirmed that the woman has two copies of the mutation ApoE3 Christchurch’s mutation caused her to resist Alzheimer’s symptoms for 30 years despite having very high levels of beta-amyloid in her brain.
Methods to prevent Alzheimer’s disease
Although there are genetic factors that can determine a person’s risk of developing Alzheimer’s disease. The 2020 report Lancet It has been suggested that alcohol consumption, smoking, malnutrition, lack of education, lack of social contact and lack of physical activity contribute to the development of the disease.
On the other hand, some studies suggest that Lifestyle interventions Stimulating brain activity can help increase cognitive concentration or relieve certain symptoms.
For example, a study published in Neurology In the year By 2021, higher cognitive activities such as reading, playing games like checkers and puzzles, and writing letters could delay Alzheimer’s disease by 5 years in those 80 and older.
Another study, published in 2022 PNASMore time spent in cognitively passive activities, such as watching television, is associated with an increased risk of dementia, while more time spent in cognitively active activities, such as using a computer, decreases the risk of dementia.
And a study from JAMA Network OpenIn the year Published in July 2023, it found that engaging in mentally challenging activities, including journaling, playing chess and solving crossword puzzles, was associated with a lower risk of dementia among older adults.
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