Gum Disease linked to Alzheimer's?

[Ser Scot A Ellison]

Wow, I'm glad I floss every day and I still have gum inflammation which with this study is rather scary:

http://www.bbc.com/news/health-35775743

From the linked article:

The study, jointly led by the University of Southampton and King's College London, cognitively assessed the participants, and took blood samples to measure inflammatory markers in their blood.

Their oral health was also assessed by a dental hygienist who was unaware of the cognitive outcomes.

Of the sample group, 22 were found to have considerable gum disease while for the remaining 37 patients the disease was much less apparent. The average age of the group with gum disease was 75, and in the other group it was 79.

A majority of participants - 52 - were followed up at six months, and all assessments were repeated.

The presence of gum disease - or periodontitis as it is known - was associated with a six-fold increase in the rate of cognitive decline, the study suggested.

[Prince of the North]

That is scary!  My first thought reading the article, however, was that correlation isn't necessarily causation (duh!).  I was really glad to see them address that at the end.  Now this study needs to be followed up with larger and, preferably, longitudinal studies to really get at the possible causal relationship.

[maarsen]

I was told by my dentist that gum disease increases with age. So does Alzheimer's.

[Fragile Bird]

The potential links of various diseases to gum disease are being examined by researchers around the world.  Iirc, research appears to indicate a correlation between gum disease and heart disease. Rot and bacteria in your mouth are being swallowed by you all the time, and of course periodontal disease causes bleeding, another avenue of spreading bacteria.

Brush!  Floss!

[maarsen]

1 hour ago, Fragile Bird said:

The potential links of various diseases to gum disease are being examined by researchers around the world.  Iirc, research appears to indicate a correlation between gum disease and heart disease. Rot and bacteria in your mouth are being swallowed by you all the time, and of course periodontal disease causes bleeding, another avenue of spreading bacteria.

Brush!  Floss!

FB, I think the reason for both is that the bacteria that are are in your mouth attacking your teeth,  are in your arteries doing nasty things also. There has been some claims of actually finding infections by these bacteria in arteries. The reaction to the infection is that your body deposits  plaque in the arteries, slowly blocking them up. Infections around your heart can cause also symptoms that mimic heart attacks. I had a cardiac surgeon and a cardiologist arguing about whether or not I had exactly that once. 

[CryptofCthulhu]

They'll come up with a study trying to link Alzheimer's to which hand you wipe your ass with at some point.

[maarsen]

1 minute ago, CryptofCthulhu said:

They'll come up with a study trying to link Alzheimer's to which hand you wipe your ass with at some point.

Always the left. I use my right to hold a fork.

[Sir Thursday]

 

 

I make a point of never trusting the journalist to get the interpretation of the study right any more. They're wrong SO often, it's just not worth reading anything other than the primary source if you want to get the facts right. Surprisingly, the BBC didn't even include a link to the study in the article, just a link to PLoS One - rather annoying. Fortunately I was able to find the full journal with a brief search - see here: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0151081

First off, the headline of the BBC article is straight up wrong.  From the first line of the abstract:

Quote

Periodontitis is common in the elderly and may become more common in Alzheimer’s disease because of a reduced ability to take care of oral hygiene as the disease progresses.

Point being - the study makes no claims about gum disease causing Alzheimer's. There may be a correlation between the two, but it is not the case that having gum disease makes you more likely to have dementia or similar and the study is emphatic about that point.

Reading through the study, what it seems to be trying to show is that people who already have Alzheimer's may see more cognitive decline if they also have periodontitis. Now, that would be an interesting conclusion, but it's nowhere near as big a statement as "Gum disease linked to Alzheimer's".

On top of that, the study was only done on 59 people - hardly a high power study. From the write-up:

Quote

the small numbers of participants in this study cannot rule out that the relationship is due to chance and the study needs to be replicated.

So essentially what they're saying is that in small scale they found something worthy of further follow-up. But it's only after that rigorous follow-up that any substantive conclusions could be drawn.

Worth also mentioning the following snippet from the Statistical Analysis section:

Quote

In this pilot study we made no explicit allowance for multiplicity of testing, and therefore make no claims about significance where an adjustment of the type I error rate (e.g. Bonferroni) would lead to a given p-value no longer reaching statistical significance. Multivariate analysis was used to adjust for possible confounding effects of age, gender and baseline cognitive status.

What this is basically saying is that they didn't bother to control for the possibility of falling into this trap:

Now, that's OK as long as they're up front about - and they are! The whole tenor of the paper is that further research is required to determine what's going on here. But that all gets lost in the translation from paper to journalistic write-up.

So yeah, not particularly impressed with the journalistic integrity of that BBC article, and I wouldn't be particularly worried if you have periodontitis Scott :).

ST

[Iskaral Pust]

There was already a good study that upgraded a long-observed correlation between gum disease and heart disease to causation by the former. The inferred mechanism is that swallowing the bacteria causes inflammation and plaque in arteries.

It's plausible the plaque and arterial hardening also contribute to dementia via mini-strokes, although that's a different condition to Alzheimer's, even if the symptoms and outcome are similar.

I find that alcohol mouth wash (Listerine, rather than Scope) twice a day is a very effective preventative in addition to brushing, flossing and semi-annual dental visits. Before using Listerine, I used to have gum inflammation for the last several weeks before a dental visit.