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Meatrition OP t1_jbbve1v wrote

Published: 03 February 2023 Oral hygiene, mouthwash usage and cardiovascular mortality during 18.8 years of follow-up

Sok-Ja Janket, Caitlyn Lee, …Jukka H. Meurman Show authors British Dental Journal (2023)Cite this article

6101 Accesses 280 Altmetric


Aim(s) We tested the following hypotheses: would better oral hygiene self-care (OHS) influence cardiovascular (CVD) mortality? Will using mouthwash in addition to OHS affect CVD mortality? How does mouthwash usage impact the oral microbes?

Design and methods Among 354 dentate subjects from the Kuopio Oral Health and Heart study, the association of OHS with CVD mortality was assessed using Cox regression analyses, adjusting for age, sex, smoking, dyslipidemia, diabetes, hypertension and education. Additionally, whether using mouthwash would affect this relationship was evaluated.

Results In the multivariable-adjusted models, OHS was associated with a 51% reduction in the risk of CVD mortality (hazard ratio [HR] 0.49 [0.28-0.85]; p = 0.01). Even those who had coronary artery disease at baseline showed a marginally significant benefit (0.50 [0.24-1.06]; p = 0.07). However, mouthwash usage did not change OHS effects (HR = 0.49 [0.27-0.87]; p = 0.01), indicating no additional benefits nor detriments. All tested microbes trended to decrease with mouthwash usage in the short term, but none were statistically significant.

Conclusion Good OHS significantly lowered the risk of CVD mortality relative to poor OHS. Mouthwash usage did not show any long-term harm or benefit on CVD mortality beyond the benefits rendered by brushing and flossing.

Key points Good oral hygiene self-care (OHS) that encompasses both brushing and flossing was associated with significantly lower risk of cardiovascular mortality compared with poor OHS during a median follow-up of 18.8 years.

The patients who had coronary artery disease at baseline also experienced a marginally significant decrease in the risk of cardiovascular mortality with good OHS (p = 0.07).

The additional use of mouthwash with OHS did not influence the risk of cardiovascular mortality.


Meatrition OP t1_jbbvogn wrote

OHS Defined:

Using Statistical Analysis System version 9.4, we combined the binary variable of brushing daily 1/0 and flossing daily 1/0, and categorised the cohort into four mutually exclusive groups: group 0 consisted of those who never brushed or flossed; group 1 consisted of those who flossed but not brushed; group 2 consisted of those who brushed but not flossed; and group 3 consisted of those who brushed daily and flossed. There were only four people in group 1 and we merged them into group 0. Thus, OHS group 0, 1 and 2 were created: 0 being the poorest oral hygiene group (poor OHS and reference); 1 being those who brushed daily but not flossed (good OHS); and 2 being those who brushed and flossed (better OHS). Because the sample size in Cox regression is event rate (that is, CVD mortality), the sample size in this study is very small between 40-50. Thus, to save the degree of freedom (statistical power), we used linear trend models whenever possible. Combining people who never brushed and brushed seldom led to the reference group (n = 41). Next, we generated two levels of OHS, namely, who only brushed daily (n = 261) (OHS level 1) and the 57 people who brushed and flossed became OHS level 2. The baseline characteristics were stratified by OHS categories and compared by non-parametric three-group comparison by Kruskal-Wallis test or chi-squared test.


Emberashh t1_jbbvzf2 wrote

Were they able to identify what specifically caused the apparent reduction or is that still unclear?


UterineTemple t1_jbbxkma wrote

I have a strong suspicion that anyone who prioritizes taking care of themselves is likely going to be healthier than those that don’t. So don’t hoard mouthwash just yet.


Emberashh t1_jbbykxe wrote

Darn. Im highly curious as to whats connecting the two.

Unless its like a weird roundabout gut flora thing. May be bad oral hygiene leads to you ingesting bad stuff too much and thats how it throws things off?


CogitusCreo t1_jbbzt9d wrote

This study didn't dig that deep, but a similar study about alzheimers and oral hygiene speculated that bacteria can enter the bloodstream and end up in the brain. I think they may have been looking at the use of mouthwash with xylitol. I can't find that exact study now, but you might like these:

Edit: I'm talking about mouthwash below. Edit 2: Keep xylitol away from your dog! It's fatal to them.
Xylitol is great, BTW. A scientist friend of mine said that bacteria absorb it like sugar, but can't metabolize it, so they die (that may be a massive oversimplification). More info here:


1thenumber t1_jbc5c0m wrote

Epidemiology cannot speak to causation, so you are jumping too far ahead. It can generate a hypothesis that can then be tested in a controlled trial. But asking people to self-report on habits over a long period is not going to tell us cause; it is going to tell us what every similar study does - that healthy people are healthy, and unhealthy people are unhealthy.

The healthy group in this case might be simply healthy because they care about being healthy - they are "adherers" or "compliers". There's a really fascinating study that was done in 1980 on a cholesterol drug called clofibrate, where the initial results were unspectacular when compared to placebo. The clofibrate showed no improvement over the placebo group in terms of mortality.

However, when those two groups were split again between "adherers" and non-adherers, the adherers in BOTH groups saw almost the exact same reduction in mortality that the mouthwash study saw - about 50%. This means in a placebo group, where no actual intervention was being taken, simply adhering to the instructions given by the study was enough to almost halve your mortality risk.


Sanpaku t1_jbcnkt3 wrote

There's a rather long history of epidemiology showing an association of periodontitis with systemic chronic diseases, and the main candidate mechanism is that bacterial lipopolysaccharides, one of the most inflammatory compounds known, circulates from the gum to other tissues.

An older review, but still worthwhile:

Kaur et al, 2016. Unraveling the link between periodontal health and cardiovascular diseases. J Dent Sci Oral Rehab, 7, pp.28-35.

I'll admit to not having the best oral hygiene, largely because I haven't had any dental issues for 30 years. I brush maybe once a day. Floss once a week. But when I encountered the evidence on periodontitis and CVD I bought a bottle of Listerine and keep it in the car. Swishing Listerine around my mouth became part of the morning and evening commutes.


Capn_Zelnick t1_jbcs9o4 wrote

Good lord, not brushing your teeth makes you die of heart disease!



SemanticTriangle t1_jbdadh6 wrote

Dental hygiene companies reached saturation with toothbrushes, toothpaste, and floss, so created a new pointless product to sell. It gave people oral cancer.

That's the strange phenomenon explained. If you need to wash your mouth out, salt water or even just water will do.


wealhtheow t1_jbdc2w5 wrote

There's a paragraph of Methods on how they chose to deal with those: Confounding factors Age in years and smoking in three categories (never, past and current smokers) were assessed. Total cholesterol, triglyceride and high-density lipoprotein cholesterol (HDL) were measured by the automated enzymatic technique. We assessed dyslipidemia by total/HDL cholesterol ratio which was proven the best predictor of future atherosclerosis.30 Diabetes was ascertained by medical record review. Subjects were considered to have diabetes if documented diagnoses were in the medical records or if they were being treated for diabetes. To avoid confounding by affluence and high socioeconomic status, we adjusted educational levels, income and private insurance status.


dgunn11235 t1_jbdr0dt wrote

I ask my patients - get your dental check up. I've seen cardiovascular disease from dental disease directly yes, but I think it is healthy for inflammatory reason besides the obvious other comments. above.


FluffyCloud5 t1_jbdrs0e wrote

No it isn't.

Teeth plaque is a matrix of microbial biofilms, extracellular matrix components, sugar, DNA, and various metabolites.

Plaque that builds up in arteries is typically a mixture of calcium, fibrin, fats, clotting factors and waste components.

Sometimes microbial plaques get bloodborne and can colonise an artery, forming microbial plaques which are dangerous. But they are relatively rare and not the same as normal arterial plaque buildup.


filodendron t1_jbdsy4h wrote

Don't dismiss the connection without reading or knowing a bit more of the medicine behind it.

As a dental veterinarian. We have clear indications of poor dental hygiene and heart disease (specifically valvular disease) and more commonly in certain breeds (cavaliers).

Bacteria in the mouth (more bacteria in a mouth suffering from periodontal disease) travel to the stomach and through the bloodstream to the heart where they attach to the valve - worsening the prognosis severely.

But you don't need mouthwash for most dogs. You need to brush once a day - clear studies on that as well.


FluffyCloud5 t1_jbdvebt wrote

For some reason I can't see your other response or reply to it, but you asked if this article was wrong:

The answer is yes, this article is incorrect. The plaque that builds in arteries with microbes in them (I suppose this could be considered the "same plaque as the teeth") occurs very rarely and is not the same as the normal plaque that builds up without microbial components.


nyet-marionetka t1_jbe0dyo wrote

I think there’s more to it than that. Very bad dental hygiene has a risk of endocarditis. Bacteria can enter the bloodstream through damaged mucosa in the mouth and colonize heart valves. I’ve seen it proposed for years now that this happening to a lesser extent can contribute to systemic inflammation that contributes to cardiovascular disease.

Edit: Also the study found mouthwash itself doesn’t do a damn thing.


wallybuddabingbang t1_jbe2dfu wrote

I thought mouthwash was allegedly a marketing scheme (halitosis) but is it a legit part of a good oral hygiene routine? I brush 2-3x a day and floss daily and drink lots of water. Should mouthwash be integrated into this routine? Also wondering as I have two young kids and want to get them on the right track.


GlobularLobule t1_jbe2o81 wrote

Probably that's broadly true, but I know my dad is obsessed with oral hygiene (to the point he'll randomly text me or my sister and be like 'remember to floss!') But he's sedentary, obese, drinks too much, and eats a high salt, high saturated fat diet. So there are definitely cases where oral hygiene isn't indicative of general self- care and wellness.


wallybuddabingbang t1_jbe6o5n wrote

Wow, just googled and found an NIH study on this. So does a saltwater rinse kill the bacteria that can make its way to your brain? It’s very hard to know what the best thing to do for your health actually is.


Relative-Dream-4804 t1_jbebw2w wrote

I learned the power of dental floss long ago! I get an A+ during my cleanings! Just flossing makes a huge difference.


Nayir1 t1_jbecdq9 wrote

As to the edit, what we mean by 'mouthwash' kind of matters. Like certain types of bacterial infection can be exacerbated by Listerine and the like, where cheap as dirt hydrogen peroxide or simple salt water can be beneficial.


OniKanta t1_jbejlcz wrote

And yet Dental insurance is still completely separate from Healthcare insurance.


cookiedux t1_jben40g wrote

Gingivitis is a major risk factor for rheumatoid arthritis.

I think the reason oral health is so crucial is because your teeth are connected to your bloodstream for nourishment (at least if they are vital teeth) and it’s extremely easy for bacteria etc in your mouth to enter your bloodstream directly. That’s a unique situation compared to other places on your body.

You can get all kinds of cardiovascular viruses/infections this way. My uncle got pericarditis this way.

If you have an abscessed tooth, treating it quickly is extremely important. An abscessed tooth can give you sepsis very quickly.

Anyway, only tangentially related, but there are a lot of anatomical issues that make your oral health really crucial to your overall health.


Adamworks t1_jbenvar wrote

>Even those who had coronary artery disease at baseline showed a marginally significant benefit (0.50 [0.24-1.06]; p = 0.07).

This statement is wrong on multiple levels, I can't believe Nature would not catch that in the abstract.

  1. They don't clarify if they are referencing statistical significance;
  2. It is not significant at p = 0.07
  3. It is likely not even near significant if they accounted for multiple comparisons (p-hacking).
  4. Under the hypothesis test framework, things can't be marginally significant. It is either significant or it isn't.

ApricatingInAccismus t1_jberqev wrote

The most obvious confounder, though, would be that someone who has the discipline to develop lifelong habits of oral hygiene very likely also has the discipline to develop lifelong healthier habits of nutrition and exercise (which are strongly associated with cvd).


RunsWithApes t1_jbfc5cr wrote

Doc here - There is also a direct correlation hence why it is a requirement prior to surgery (especially in cardiology and orthopedics) for the patients to be cleared of all dental infections. We've known this for awhile now.


niconiconicnic0 t1_jbhr3i2 wrote

Mouthwash is actually not only ineffective, it is directly linked to increased blood pressure and hypertension via reducing bacteria involved in nitric oxide production which influences blood pressure.

Conclusion: In this study, frequent regular use of over-the-counter mouthwash was associated with increased risk of hypertension, independent of major risk factors for hypertension and several other potential confounders.”


Critically reviews evidence from a published study that suggested mouthwash use is associated with increased risk for prediabetes/diabetes.”

“those using mouthwash twice daily or more at baseline had an approximately 50% increased risk of developing prediabetes/diabetes combined, compared to those who used mouthwash less than twice daily or not at all.”