[hajile]

Who knows. I'll give you an interesting thought.

There is NO single, conclusive test for Alzheimer's disease. The symptoms are almost identical to CJD (human mad cow) with the biggest differentiator being time from diagnosis to death. Even Amyloid-beta plaque buildup is often (though not always) noted in CJD patients [0][2]. Likewise the other Alzheimer's marker tau protein is also elevated in CJD patients [3]. I'd note that we don't actually know that CJD must progress over 1-2 years rather than a decade -- it is an observational assumption.

Between 15-30% of Alzheimer's diagnosed patients also don't have the normal Alzheimer's brain symptom (presumably amyloid buildup) either. Alzheimer's as cause of death was 17.6% in 2000, but is now 37.3% in 2020.[1] Because CJD is defined as killing quickly, it isn't even checked for in such cases (a kind of self-fulfilling prophecy if the diagnosis criteria aren't actually accurate). It doesn't help that cleanup of a contaminated area is time consuming and costly (not to mention potential negative press and panic).

This isn't a new idea, but perhaps those fears were somewhat true, but have been buried under our lack of knowledge of protein diseases.

[0] https://pubmed.ncbi.nlm.nih.gov/3092727/

[1] https://alz-journals.onlinelibrary.wiley.com/doi/full/10.100...

[2] https://pubmed.ncbi.nlm.nih.gov/12891683/

[3] https://pubmed.ncbi.nlm.nih.gov/20881758/

[incrudible]

> The symptoms are almost identical to CJD (human mad cow) with the biggest differentiator being time from diagnosis to death.

Ordinary CJD has a much lower median age of death (68 years) than Alzheimer's (88 years), but vCJD (the form that is believed to be caused by contaminated food) has a median age of death of only 28 years.

https://en.wikipedia.org/wiki/Creutzfeldt%E2%80%93Jakob_dise...

A surge in young or middle-aged dementia cases would likely not have fallen under the radar.

> Between 15-30% of Alzheimer's diagnosed patients also don't have the normal Alzheimer's brain symptom (presumably amyloid buildup) either. Alzheimer's as cause of death was 17.6% in 2000, but is now 37.3% in 2020.[1]

You have mistaken the rate of deaths (per 100,000) for the percentage. When judging this increase, one must consider that in the same timeframe, the mean age of the population has risen by 10% and life expectancy increased by more than two years.

[hajile]

> You have mistaken the rate of deaths (per 100,000) for the percentage. When judging this increase, one must consider that in the same timeframe, the mean age of the population has risen by 10% and life expectancy increased by more than two years.

Sorry, knew what I meant, but messed up what I typed. In any case, doubling the death rate per 100k is still much greater than the 10% age and 2-3% lifespan increase would indicate. Alzheimer's mortality had increased 16x between 79 and 91 (from a mere 857 to 13,768 in 1991[0]. The previous study I quoted above put the 2018 mortality at 122,019. Alzheimer's is now the 6th leading cause of death and continues to rise at a rapid rate.

> Ordinary CJD has a much lower median age of death (68 years) than Alzheimer's (88 years), but vCJD (the form that is believed to be caused by contaminated food) has a median age of death of only 28 years.

This is the crux of the problem.

We have experimental knowledge about this from kuru. The last patient displayed symptomatic kuru some 5 decades after the cannibalistic practices had stopped.

Do only young people eat meat? If all age groups eat meat at equivalent rates and infection rates in cattle are constant (believed to be around 1 in a million IIRC), then the median age should be the population median age PLUS a shift for however long it takes to become symptomatic.

Linkage is also important. How do we know that CJD and vCJD are different? We made that distinction arbitrarily and don't have evidence that "normal" CJD is not caused by external sources. Official vCJD cases are around 200 over the past 30 years, so there isn't exactly huge amounts of data to pull from either.

If CJD really did explode in the 80s-90s, then you would expect the older generation to become symptomatic at an older age than would be typical if the disease were common in the decades before.

There seems to be a connection with being vegetarian/vegan and alzheimer's but how much is due to not eating meat and how much is due to overall healthy lifestyle is hard to determine.

Something weird is going on with Alzheimer's disease and the legit explosion in cases over the last 30 years (both per capita and as cause of death in the elderly) give reason to wonder what weirdness is going on.

[0] https://www.cdc.gov/nchs/data/series/sr_20/sr20_028.pdf

[chasil]

Here is another major difference:

"We know that the β-A4 amyloid of Alzheimer’s disease also derives from a normal host protein that in diseased people accumulates in the brain, but it does not have the ability to transmit disease to a healthy person. Why this difference?"

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1114482/