[mobilejdral]

Actual paper: https://pubmed.ncbi.nlm.nih.gov/39235810/

> Conclusions and relevance: In this cohort study, a history of upper gastrointestinal MD was associated with elevated risk of developing a clinical PD diagnosis. Increased vigilance among patients with MD for future PD risk may be warranted.

Associated is the key word. The washington post sensationalizes it to "may begin in the gut"

[ninetyninenine]

That is not a sensationalization.

association indicates possibility of causation. The washington post used the right wording here.

While association does not imply causation, you very much need an association in order to establish causation. You actually need establish two associations in order to verify causation, so the existence of one type of association is already an indicator for "may begin in the gut".

[quonn]

You can‘t verify causation with two associations either.

[ninetyninenine]

Technically causation can never be verified.

But practically you need to associate cause and effect and lack of cause and lack of effect. That is two associations, and in one association the experimenter himself must deliberately influence the experiment.

This verifies cause from a practical perspective. From a technical perspective causation was not verified. Because technically you need to verify both effect and lack of effect from one population on the same event and the only way to do that is time travel.

We influenced the experiment by creating the causation but by doing that we can no longer know what would’ve happened if we didn’t create the causative precursor and thus we can never truly know if the event actually caused the effect.

[tim333]

Technically sometimes causation can be verified. Say you break your arm in a car crash - it's pretty clear what caused what. I'll give you that with things like gut problems and Parkinson's it's tricker.

[OutOfHere]

> it's pretty clear what caused what.

It really isn't. Maybe your arm was osteoporotic or weak from a prior incident, and it broke due to a trivial pressure injury when the ambulance workers were loading you into the ambulance.

The point is that it's pretty clear only when it can be mathematically proven, and at all other times it's based on some idea of probability. In the case of this article, a causal association seems quite probable to me.

[ninetyninenine]

I’m of course referring to formal verification. Which means give me 100 percent concrete proof the car crash was causative. This is science and this is what all of science strives and ultimately fails to achieve.

For your example you didn’t prove anything. You gave me an arbitrary example and hoped I would understand your point through an example. I do understand your point but you failed to understand my point.

Your example is only an empathic offering of understanding but it doesn’t offer proof of your statement. Show me a formal proof of something that was causative. Anything.

You will find that on multiple levels of resolution not only can causation not be formally proven but that science can never prove anything in reality. Proof is the domain of maths and logical games of axioms and theorems we play with arbitrary rules, it does not actually apply to reality.

[Mistletoe]

The paper is about the gut-first hypothesis of Parkinson disease (PD), I don’t think the Washington Post sensationalized it that much. And the p-values they find are pretty amazing. P<.001 and still P=.01 after covariate adjustment.

[cpncrunch]

It doesnt show direction of causality. Dopamine is also an important gut neurotransmitter.

[yieldcrv]

and neither will the proposed treatments, and neither will the clinical trials, and neither will the approved drugs

[cpncrunch]

My point is that its plausible there is no direction. It could be dopamine causing both effects.

[FollowingTheDao]

I agree. They know dopamine makes things worse for PD pateints.

My Theory: The reason that Dopamine fails is because they do not have low dopamine, but low energy for the dopamine receptor. The dopamine receptors are G Coupled Protein receptors that need GTP to function. So if you are low in the purine GTP then it does not matter how much dopamine you make.

Giving these patients dopamine works, but then fails, because it depletes the cells of GTP.

[jxntb73]

speculative.

[FollowingTheDao]

My work is not based on conjecture, it’s based on knowledge. So it’s not speculative, it’s a hypothesis.

This is how science works.

[0xdde]

The p-values don't say anything about the size of the effect. With a large sample size, they are almost guaranteed to be small. In fact, the confidence interval after covariate adjustment comes very closing to containing the value 1, which suggests no substantive change between the groups.

[throwaway920102]

> MD

mucosal damage

[m463]

I was curious so I searched. I wonder if other conditions set up parkinsons? (Also disorders might != damage)

Causes and Diagnoses of Mucosal Disorders

The causes of mucosal disorders are generally bacteria, viruses or fungi, such as yeast. A weakened immune system, stress or dietary deficiencies can make you more prone to a mucosal disorder.

Mucosal disorders can develop in a variety of ways:

- Candidiasis is often caused by humid conditions, damaged skin or a depressed immune system.

- Canker sores are the result of a condition called aphthous stomatitis, and brought on by a weakened immune system, food allergies, viruses, bacteria and poor nutrition.

- Herpes is spread through skin-to-skin contact such as kissing and sexual intercourse. It can also be passed via a glass or lip balm of someone who has the herpes simplex virus. It can be contagious even when no lesions are present.

https://www.nm.org/conditions-and-care-areas/dermatology/muc...

[baxtr]

I mean it could be either of these three:

(1) MD induces PD

(2) PD induces MD

(3) some other underlying condition causes both MD and PD

[arcticbull]

Or (4) two unrelated things that just so happen to be coincident.

https://www.tylervigen.com/spurious-correlations