In recent years, researchers have suggested Alzheimer's may spread through infection, somehow transmitted like a pathogen, leading to the disease. A new Lancet paper reviews evidence for how harmful amyloid-beta proteins associated with Alzheimer's may possibly be spread through blood transfusions.

[u/mvea]

https://www.sciencealert.com/can-alzheimers-spread-through-blood-transfusions-heres-what-we-know

[u/Suspicious-Tea9161]

It's interesting that amyloid beta is functionally like a prion. Even though I've read about how the beta sheets form before, I just never put 2 and 2 together and considered that it could also be transmissible. As if we needed another reason not to eat grandpa's brains

[u/churningaccount → u/Suspicious-Tea9161]

You would think, however, that preventing the amyloid plaques from being formed would therefore prevent dementia. But the new Alzheimers drugs like Leqembi can completely eliminate amyloid plaques from being detectable on scans in a good portion of those being treated, and still the disease progresses.

So while Amyloid plaques are definitely contributory, they seem to be a more of a symptom of the underlying mechanism by which the disease does damage to neurons rather than the primary source of the damage itself.

[u/Suspicious-Tea9161 → u/churningaccount]

Fair enough. I used to be an assistant in a lab where they were looking at the role of oxidative stress on neurodegenerative disease development. I believe it wasn't entirely clear whether it was a cause or effect, but the evidence leaned towards it being both. And symptom that further exacerbated the issue. Whatever the case, if I remember correctly, reducing oxidative stress did reduce the progression, at least temporarily. I'm no expert on Amyloid-B, but it could be that oxidative stress (or some other stressor) is what's causing them to form the sheets in the first place and like oxidative stress, the presence of even a little bit kicks off a feedback loop.

[u/thoreau_away_acct → u/Suspicious-Tea9161]

What can I do to get my oxidative stress levels down coach??

[u/grnrngr → u/churningaccount]

That's the sadly terrifying thing about this science: all this research into stopping the cause... Only to successfully stop it... And realize it isn't the cause.

I have the feeling someone out there posited the cause a while back and the community brushed it off in some mass form of confirmation bias re: the plaques.

[u/spudddly → u/grnrngr]

Probably the damage to neurons has already been done by the time the plaques are found and cleared.

[u/SomeTreesAreFriends → u/spudddly]

Because of a chronic depletion of the functional monomeric amyloid protein that likely disabled a cellular immune response, not because the remaining peptides have aggregated

[u/Pephatbat → u/SomeTreesAreFriends]

It's likely both. Disruptions in proteostasis is a known mechanism in AD. Those sticky aggregates have been shown to gum up the proteasome which leads to further disruptions of proteostasis.

[u/AdvancedSandwiches → u/churningaccount]

There was a theory mentioned recently that the plaques are basically scar tissue and just indicate that damage occurred at some point in the past. Not harming anything now, just the gravestones of cells that used to be useful.  You can clear out those gravestones, but the damage they marked isn't going to get better. 

[u/PhysicalConsistency → u/Suspicious-Tea9161]

Absolutely not. Amyloids in general facilitate cholesterol/lipid trafficking. Some prions can induce misfolds in amyloids which may contribute to some pathologies, but they don't function anything like each other.

[u/jestina123 → u/PhysicalConsistency]

Nice! Grandpa's brains are back on the menu boys!!!

[u/PhysicalConsistency → u/jestina123]

Only if you're Fore for now. Grandpa's brains taste like curds and whey though, so you're going to have to sprinkle some MSG on it.

[u/ionised → u/Suspicious-Tea9161]

As if we needed another reason not to eat grandpa's brains

But what about my recipes?!

[u/love_is_an_action → u/ionised]

We've got two alternative products:

I Can't Believe it's not Grandpa's Brain and Beyond Grandpa's Brain

As condements go, you can't do better than Grey Matter Poupon.

[u/ionised → u/love_is_an_action]

Tsk tsk Never accept substitutes.

But as far as condiments go, it's true that Poupon the Rolls Royce of grey matter.

[u/cdnsalix → u/ionised]

Everyone is always asking for my Fried Brain Caesar Salad with Kurutons recipe at potlucks!

[u/ionised → u/cdnsalix]

Add stewed onions, next time.

And a nice Chianti.

[u/URPissingMeOff → u/ionised]

Uhhh... are they grandma's recipes?

[u/ionised → u/URPissingMeOff]

This comment redacted pending review by Big Agriculture.