Alzheimer’s disease is the most common type of dementia in the world ; between 50 and 70% of all cases. This makes it a well-studied ailment, but there are still many unknowns about treatment, causes and prevention.
Alzheimer’s is a neurodegenerative disease, which causes damage and death of neurons and their connections, which leads to a progressive deterioration of the biological functions of the body. Regarding its origin, we know that there are two proteins involved: neurofibrillary tangles and beta-amyloid protein plaques . These proteins are deposited within the neuron until damage occurs and they die.
There are also genetic causes (several genes have been identified, such as PSEN1 and PSEN2) that cause Alzheimer’s. In these cases, we speak of familial or hereditary Alzheimer’s. Most of these inherited genetic mutations show the first symptoms before the age of 60, and they only explain 1 to 5% of all cases.
There are many lines of research working to elucidate more clearly the causes of Alzheimer’s : how these harmful proteins develop and how they are deposited in neurons.
Once this introduction is made, let’s move on to explain the content that concerns this article.
Aluminum and Alzheimer’s
Recent research had already measured a high aluminum content in the brain tissue of patients with familial Alzheimer’s disease . Now, a new study published in the Journal of Alzheimer’s Disease has sought to delve into the role that this mineral has in the production or deposit of these harmful proteins, causing Alzheimer’s.
The hypothesis the study wanted to test was that human exposure to aluminum is related to the etiology (studying the cause) of Alzheimer’s disease.
An important point: this study was carried out only in patients with familial or hereditary Alzheimer’s (that is, those cases in which there is an implicated gene) Therefore, we cannot say that the results are valid in cases of sporadic Alzheimer’s, the one whose causes are unknown.
Let’s see, now, what were their conclusions.
Method
The researchers obtained brain tissue from a donor cohort with inherited Alzheimer’s disease. They then measured the aluminum content of these tissues and compared the data with healthy brain tissues.
Aluminum deposition in a senile plaque in the temporal cortex of a donor with inherited Alzheimer’s disease. / Journal of Alzheimer’s Disease.
Results
The scientists did indeed find “significantly higher” levels , as cited in the study, of aluminum in Alzheimer’s brains than in control tissues from donors without neurological impairment.
How is aluminum detected in a brain? The researchers used aluminum-specific fluorescence microscopy alongside other images that, in turn, revealed the presence of beta-amyloid proteins.
” We have managed to demonstrate a very high degree of co-localization of these two risk factors (aluminum and beta-amyloid proteins) in brain tissue in familial or hereditary Alzheimer’s disease, ” the researchers report in the publication.
Let’s remember: familial Alzheimer’s accounts for only 1 to 5% of cases of this type of dementia.
Aluminum and beta-amyloid proteins co-located in the senile plaques of neurons. Aluminum was also found separately from beta-amyloid proteins in intracellular compartments.
Conclution
Research has identified a possibly unique association thus far between high aluminum content in the brain and beta-amyloid proteins, which allows us to postulate that the genetic predispositions that define familial Alzheimer’s disease underlie this relationship.
This study brings us closer to a better approximation of the causes of hereditary Alzheimer’s, which could allow us to work along lines of prevention and treatment.
The relationship of aluminum observed in this research, as we mentioned, is valid for cases of hereditary Alzheimer’s , which occurs early (symptoms before 60 or 65 years) and with two or more family history of this disease.
There could also be genes involved in causing late or sporadic Alzheimer’s, but its clear cause remains an unsolved puzzle.
Reference:
Mold, Matthew. Aluminum and Amyloid-β in Familial Alzheimer’s Diseas e. Journal of Alzheimer’s Disease, vol. Pre-press, no. Pre-press, pp. 1-9, 2019. Doi: 10.3233 / JAD-191140
