Headlines Tout “Contagious Alzheimer’s” Finding – But What’s the Real Story?
In the past week, you may have seen a few news headlines that talked about the idea that Alzheimer’s disease may be contagious. I’ve seen headlines like ”Alzheimer’s Disease Contagious Like Mad Cow,” “Some Cases of Alzheimer’s May Be Transmitted,” and “Can You ‘Catch’ Alzheimer’s Disease?” Those all sound pretty scary, like something out of a sci-fi movie about a looming global Alzheimer’s pandemic. But when you look at the finding that spawned these sensational headlines, you may be comforted to know that the research does not show anything quite so dire.
The study involved injecting human brain tissue into mice, a condition which researchers admitted was highly artificial. The summary version of the study is that researchers took proteins from the brain of humans with Alzheimer’s and put them into the brains of healthy mice. The mice then developed Alzheimer’s. The conclusion, that injecting diseased brain tissue into a healthy brain causes disease, led to this notion that the mice “caught” the disease from the human tissue. But how often do you inject tissue from one brain into another, outside of an experiment? And do I need to point out that this was a case of inter-species brain tissue injection, an even more unlikely scenario? If you decode what the paper actually reports, it’s even less scary. The paper, entitled De novo induction of amyloid-ß deposition in vivo, looks at just one associated (not causal) factor of AD, which is amyloid-β proteins.
The researchers who were interviewed mentioned that there was a resemblance to Mad Cow disease from the standpoint of how the proteins in the brain were affected, but they did not imply a similarity in how it was transmitted. Unfortunately some journalists have chosen to interpret this by making dramatic statements like “Imagine having to deal with an elderly loved one wearing a moon suit? Terrible.” In my opinion, this type of reporting is incredibly irresponsible. As with so many journalistic distillations of complex scientific findings, headlines like these don’t get at the real story, choosing instead to extrapolate from the actual finding to craft a more sensational story.
I do not wish to denigrate the significance of this preliminary finding, because I believe it could help us get closer to understanding the underlying mechanisms of AD. However, I am deeply troubled by the misrepresentation of the reporting in these articles. Could aspects of Alzheimer’s be infectious under certain but limited circumstances involving tissue transplantation? Maybe. Should you be scared to give grandma a hug because you’re going to “catch” AD from her? No. While these kinds of studies are crucial to our growing understanding of AD, representing them inaccurately with sensationalized headlines is fear-mongering at its worst.
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Posted: Alzheimer's disease, Research studies


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December 16th, 2011 at 1:29 pm
Really enjoyed the article. One more thing I’m sure could be important to all the readers is if you could please explain the main difference between dementia and Alzheimer’s Disease.
December 16th, 2011 at 2:02 pm
Thanks for your fascinating article. Something else I wanted to mention is that there are several dementia stages and dementia types and it is especially essential to get diagnosed early to find out precisely what kind of dementia you’re suffering from and how far along the dementia has developed.
December 23rd, 2011 at 4:26 pm
I was just Googling this topic.
I live with my grandmother who has Alzheimer’s, as well as a recent diagnosis of high blood sugar.
I had used the lancet on her finger, trying to get a drop of blood for the routine blood sugar test. Afterwards, I went to change the lancet tip, and dropped it on the floor. As I reached for it, I poked my own finger with it, enough to draw slight blood.
At first, I thought nothing of it, as I had never heard of things like Alzeimer’s being contagious. But I decided to Google it, for my own peace of mind.
Big mistake.
Thank you for your article.
January 6th, 2012 at 11:17 am
@Michael G – glad to have put your mind at rest.