I almost couldnt believe this but my wife said it had to be something that was medically transmitted or a blood transfusion, and she wasn't far off...

"First-ever study finds that Alzheimer's Disease can be transmitted between people.

In a major discovery, scientists have presented the first evidence of Alzheimer's disease transmission in living individuals. A recent paper published in Nature Medicine sheds light on a remarkable case where Alzheimer's appears to have been medically acquired through the transmission of the amyloid-beta protein.

Typically considered a sporadic condition of late adult life or an inherited condition resulting from faulty genes, Alzheimer's disease has long remained a complex puzzle for researchers. However, this new study brings to the forefront a unique scenario, where the disease was seemingly transmitted through medical treatment.

The individuals in question had all received a type of human growth hormone known as cadaver-derived human growth hormone (c-hGH) during their childhood. This hormone was derived from pituitary glands harvested from deceased individuals and was employed to treat various causes of short stature. Remarkably, c-hGH was administered to at least 1,848 people in the UK between 1959 and 1985.

Unfortunately, c-hGH was withdrawn from use in 1985 due to the realization that some batches were contaminated with prions, infectious proteins known to cause Creutzfeldt-Jakob disease (CJD). Consequently, synthetic growth hormone, devoid of the risk of transmitting CJD, replaced c-hGH in medical practice.

Previous research by these scientists had already established a link between c-hGH treatment and the premature development of amyloid-beta protein deposits in the brains of some patients diagnosed with iatrogenic CJD.

Furthermore, in a 2018 study, they demonstrated that archived samples of c-hGH were indeed contaminated with amyloid-beta protein and could transmit amyloid-beta pathology to laboratory mice when injected.

Building upon these findings, the researchers hypothesized that individuals exposed to contaminated c-hGH who did not succumb to CJD might eventually develop Alzheimer's disease.

This latest paper details the cases of eight individuals who had received c-hGH treatment during their childhood, often spanning several years. Five of these individuals exhibited symptoms of dementia, either with a confirmed Alzheimer's diagnosis or meeting the diagnostic criteria for the disease. The onset of neurological symptoms occurred surprisingly early, with the patients ranging in age from 38 to 55 when they first experienced symptoms.

Biomarker analyses further supported the diagnoses of Alzheimer's disease in two patients and hinted at Alzheimer's in another individual. An autopsy analysis confirmed Alzheimer's pathology in yet another patient. The unusually young age at which these patients developed symptoms strongly suggests that this was not the typical late-onset sporadic Alzheimer's.

Genetic testing ruled out inherited Alzheimer's disease in the five patients who provided samples. Since c-hGH treatment is no longer in use, there is no risk of new transmissions through this method. Moreover, there have been no reported cases of Alzheimer's disease acquired through any other medical or surgical procedures, nor any indication that amyloid-beta can be transmitted during routine medical or social care.

However, the researchers emphasize the importance of reviewing safety measures to prevent the accidental transmission of amyloid-beta through other medical or surgical procedures that have previously been linked to CJD transmission.

Professor John Collinge, the lead author of the research and Director of the UCL Institute of Prion Diseases, clarified, "There is no suggestion whatsoever that Alzheimer's disease can be transmitted between individuals during activities of daily life or routine medical care." He added that these cases were linked to a specific and discontinued medical treatment involving contaminated materials.

Professor Jonathan Schott, a co-author and Chief Medical Officer at Alzheimer's Research UK, echoed the sentiment that while these cases are highly unusual, they offer valuable insights into disease mechanisms that could be instrumental in understanding and treating Alzheimer's disease in the future.

Dr. Gargi Banerjee, the first author of the study, highlighted, "We have found that it is possible for amyloid-beta pathology to be transmitted and contribute to the development of Alzheimer's disease." However, she emphasized that this transmission occurred only after repeated treatments with contaminated material, reiterating that Alzheimer's disease cannot be acquired through close contact or routine care provision.

The discovery of Alzheimer's transmission through c-hGH treatment underscores the intricate nature of this debilitating disease, paving the way for further research and a deeper understanding of its causes and potential treatment strategies.

Who has Alzheimer?s Disease? In 2020, as many as 5.8 million Americans were living with Alzheimer?s disease. Younger people may get Alzheimer?s disease, but it is less common. The number of people living with the disease doubles every 5 years beyond age 65. This number is projected to nearly triple to 14 million people by 2060. Symptoms of the disease can first appear after age 60, and the risk increases with age. What is known about Alzheimer?s Disease?

Scientists do not yet fully understand what causes Alzheimer?s disease. There likely is not a single cause but rather several factors that can affect each person differently...."..https://www.msn.com/en-us/health/other/first-ever-study-finds-that-alzheimer-s-disease-can-be-transmitted-between-people/ar-AA1qwI0G

That's one good point.
Sure hope it's true.

Is it possible that the reason mostly older people get it is that they have had longer time to be exposed to some unknown factors?

Sounds about right. Not only are they exposed longer, but it's very likely that those "unknown factors" have greatly multiplied in the last decades, as the disease is striking ever younger people