
Gum disease–causing bacteria could spur Alzheimer’s - sohkamyung
https://www.sciencemag.org/news/2019/01/gum-disease-causing-bacteria-could-spur-alzheimer-s
======
dazc
I don't know what the situation is in the US but, here in the UK, we are
bombarded with ads for products that claim to prevent or treat gum disease.

Of course, since I suffered from gum disease in my youth, I know the only way
to eradicate it is mechanically, in the dentist's chair. The process removes a
layer of gum tissue which will not grow back which then means you are much
more susceptible to the problem recurring. Extensive oral hygiene thus becomes
a way of life.

Regardless of any link with alzheimer's, I would urge anyone to avoid having
to go through this and, if you have bleeding gums, go and see a dental
professional as soon as possible - expensive mouthwash may mask the problem
for a while but it certainly won't cure it.

~~~
randomacct3847
Flossing is the best preventative solution. Daily flossing with 2x/day
brushing with a Sonicare and good mouthwash have made my dental visits much
more pleasant.

~~~
itchyouch
Make flossing even more painless and easy with a waterpik.

Using the waterpik for the first time, it was like flossing for the first time
in a while. I could taste nastiness that has been brewing in between my teeth.
The crevasses are now effortlessly cleaned out.

~~~
jonnycomputer
be careful about removing the enamel.

~~~
krageon
You're not going to be removing enamel using water at pressures like these.

------
tarcyanm
I remember the hysteria regarding aluminum cookware when higher levels of
aluminum were discovered in the brains of those who had had Alzheimer's
disease. Then it turned out that the aluminum content may simply have been an
effect of the disease, not a cause (and aluminum cookware was once again
declared, for the most part, safe). Now, with this new finding, I wonder if
part of the Alzheimer's pathogenesis isn't a leaky brain-blood barrier or
something similar that allows substances that shouldn't be in the brain
through?

~~~
aaavl2821
Some labs (including the kaufer lab at Berkeley) are investigating the leaky
blood brain barrier as a cause of Alzheimer's

------
lhl
Sadly, HN doesn't have a very good way of connecting prior threads together,
but potentially of interest, previous discussions of infection-cause theories
of Alzheimers:

3mo ago: Some studies show an association between the herpes virus and
Alzheimer’s
[https://news.ycombinator.com/item?id=18265115](https://news.ycombinator.com/item?id=18265115)

6mo ago: Alzheimer's risk 10 times lower with herpes medication
[https://news.ycombinator.com/item?id=17540094](https://news.ycombinator.com/item?id=17540094)

6mo ago: Link Between Alzheimer’s and Herpes
[https://news.ycombinator.com/item?id=17521994](https://news.ycombinator.com/item?id=17521994)

7mo ago: Researchers Find Herpes Viruses in Brains Marked by Alzheimer's
Disease
[https://news.ycombinator.com/item?id=17366591](https://news.ycombinator.com/item?id=17366591)

One thing worth noting is that some specialists believe that Alzheimer's has
multiple subtypes, eg: [https://www.foundmyfitness.com/episodes/dale-
bredesen](https://www.foundmyfitness.com/episodes/dale-bredesen)

"1\. The inflammatory subtype of Alzheimer’s disease.

A type characterized by systemic inflammation, reflected in such laboratory
results as a high hs-CRP (high-sensitivity C-reactive protein), low
albumin:globulin ratio, and high cytokine levels such as interleukin-1 and
interleukin-6.

2\. The atrophic subtype of Alzheimer's disease — a reduction in support for
synaptogenesis.

A type characterized by an atrophic profile, with reduced support from
molecules such as estradiol, progesterone, brain-derived neurotrophic factor
(BDNF), nerve growth factor (NGF), testosterone, insulin, and vitamin D, often
accompanied by increased homocysteine and insulin resistance, the last feature
of which Dr. Bredesen refers to as type 1.5 or glycotoxicity.

3\. The cortical subtype of Alzheimer's disease — an environmental toxin-
related type associated with chronic Inflammatory response syndrome (CIRS)
that presents with more general cerebral atrophy and frontal-temporal-parietal
abnormalities, resulting in an emphasis on executive deficits, rather than the
more amnestic quality of hippocampal impairment."

There's also plenty linking (and potentially reversing) Alzheimers related to
insulin resistance:

Insulin Resistance and Alzheimer’s Disease: Bioenergetic Linkages (2017)
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5671587/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5671587/)

Reversal of cognitive decline in Alzheimer's disease (2016)
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4931830/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4931830/)

Effects of ketone bodies in Alzheimer's disease in relation to neural
hypometabolism, β‐amyloid toxicity, and astrocyte function (2015)
[https://onlinelibrary.wiley.com/doi/full/10.1111/jnc.13107](https://onlinelibrary.wiley.com/doi/full/10.1111/jnc.13107)

Insulin resistance and Alzheimer’s disease (2009)
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4600067/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4600067/)

~~~
g10r
Awesome thank you.

------
ncmncm
Now we have two promising candidates for the cause of Alzheimer's --
gingivalis, and herpes-family viruses.

That doesn't mean one is right and the other wrong. Maybe herpes gets in first
and lets gingivalis in, or vice versa, or some other, more interesting
interaction.

What's tragic is that effectively none of the present researchers are
virologists or bacteriologists. As consequences, (1) progress studying and
generating a useful clinical response will be radically slowed by resistance
from the old guard to the threat to their livelihood, and (2) they will all
need to find something else to do, because you can't pick up those
specializations overnight.

The herpes connection was noted twenty years ago, but is only now getting
traction. If it's right, then almost everybody who died of AS since then was
killed by the structural resistance to the idea.

The best way to accelerate progress, now, would be to find another urgent
health problem that seems to need the skillset that had previously been
brought to bear on AS, so they jump ship and get the hell out of the way.

~~~
g10r
Certainly important for people to understand/be aware of the process someone
such as Robert Moir (one scientist mentioned in the article) must navigate

[https://www.statnews.com/2018/10/29/alzheimers-research-
outs...](https://www.statnews.com/2018/10/29/alzheimers-research-outsider-
bucked-prevailing-theory/)

------
IAmGraydon
How do you explain the rate of Alzheimer’s being higher in developed countries
where oral care is statistically better?

~~~
nabla9
Life expectancy. When the life expectancy is 50-70 years, there is less
Alzheimer compared to countries where it's above 80.

~~~
naasking
Also, better diagnostics.

------
jphoward
Time and time again we see epidemiological studies posting findings that are
clearly best explained by correlation than causation. For example, think of
the people you've met with the worst teeth. They will almost certainly, on
average, have worse overall health, lower socioeconomic status, lower
intelligence, lower paid jobs, lower educational attainment, worse diet and so
on. Surely these are just as likely, if not more, to be on the causal pathway
for Alzheimers? And that's completely ignoring the fact that people with early
Alzheimers which has not been diagnosed are much less likely to remember to
keep up with oral hygiene rules, so the risk for reverse causation is HUGE.

Now I know you're going to argue that the epidemiological studies account for
this using multiple regression and so on, but the fact is time and time again
it has been demonstrated that this just cannot be done. Indeed, vitamin D in
practically every epidemiological study to date has shown to reduce the risk
of cancer, cardiovascular mortality, tuberculosis infect. And yet, just this
month, someone FINALLY did a randomised trial of vitamin D in TWENTY SIX
THOUSAND people (the VITAL trial) and found it made no difference at all (in
fact, cardiovascular death was slightly but non-significantly more common in
the vitamin D group).

Unfortunately, people's careers and publications rely on this stuff, so it'll
keep coming. Please remain skeptical, hacker news.

~~~
notacoward
> the causal pathway

The article very clearly distinguishes between _the_ cause and _a_ cause.
"Alzheimer’s is a complex disorder, not a one stop shop" and so on.

> best explained by correlation than causation

They did more than that. They also found gingipains in the brains of patients.
Those had to come specifically from P.gingivalis infection, not the other
factors you mention. They identified a plausible causal pathway involving tau
and amyloid beta, and they _induced_ their production by introducing
P.gingivalis in mice. That's a _lot_ more than merely equating correlation
with causation.

Skepticism is good. Ignoring what has been presented is not skepticism, and
neither is jumping from correlation to non-causation. That's just
contrarianism.

~~~
josephby
Mice don’t get Alzheimer’s. Inducing plaques is not the same thing as giving
mice Alzheimer’s.

~~~
notacoward
No, it's not, but it proves that the link between gingipains and plaque is
reproducible. That's part of the causative chain, so it still refutes the glib
contrarianism to which I was replying.

------
thomasfl
So basically this says don’t get inflamations near your head?

~~~
viggity
or, perhaps, don't get the thing that causes the inflammation near your head?

------
davidivadavid
Gum-disease-causing.

------
SteveCoast
The much simpler explanation is they're both caused by carbohydrates and
especially sugar.

~~~
with_a_herring
I have an even simpler explanation : They're both caused by eating.

More seriously, yes, I agree that sugar is nasty, but it's a bit too simple to
blame it as the sole factor for all possible diseases that have a mechanism of
action that hasn't been clearly identified.

~~~
reissbaker
It's not as simplistic a claim as you might be interpreting it as: another
somewhat-well-supported theory of Alzheimer's is that it's essentially
diabetes of the brain. [1] The GP's comment re: carbs and sugar was presumably
referencing that theory.

[1] [https://www.alzheimers.net/diabetes-of-the-
brain/](https://www.alzheimers.net/diabetes-of-the-brain/)

~~~
SteveCoast
Exactly, and put better than I could.

It appears that the simplicity of the explanation is itself a problem. Surely
- all these chronic diseases can't be that simply explained? Dr. Wahls
essentially claims carbs are the root cause of MS, which she cured in herself
(with the corollary that carbs eliminate other nutrition). Dr. Fung claims
it's the root cause of diabetes. Prof Seyfried claims it's the root cause of
cancer. It surely can't be that simple?

Reading all their work, and others, I'm struck that it's very much a five-whys
scenario[1].

Also there are two points wrapped up in the original response. One is about
the cause, but there's a bigger issue about the avoidance of the problem in a
first place. If someone never eats refined carbs and therefor avoids the root
cause, why would they care about the details of the cause? We care about the
details insomuch as we would like to treat the disease, but today we can't do
that. On the other hand we do know with a lot of certainty that eating well,
fasting and exercising are good for us and avoid the problems in the first
place. For some reason, that doesn't matter as much.

The downside with treating the disease is that you also enable it, like how we
"treat" T2 diabetes by essentially just giving you more diabetes via insulin
shots.

[1] - [https://stevecoast.com/2015/03/27/the-world-will-only-get-
we...](https://stevecoast.com/2015/03/27/the-world-will-only-get-weirder/)

~~~
smn1234
Occam's razor

