Tooth Cavities May Protect Against Cancer 149
Hugh Pickens DOT Com writes "John Gever reports at MedPage Today on a new study conducted by researchers from the University of Buffalo, which found that people with more cavities in their teeth are 32 percent less likely to suffer from head and neck cancers. 'To our knowledge, the present study suggests, for the first time, an independent association between dental caries and head and neck squamous cell carcinoma.' The researchers proposed a mechanism for the apparent protective effect: that cariogenic, lactic acid-producing bacteria prompt cell-mediated Th1 immune responses that suppress tumor formation. The team examined records of patients older than 21 seen in the university's dental and maxillofacial prosthetics department from 1999 to 2007, identifying 399 who were newly diagnosed with head and neck squamous cell carcinoma. Assuming that the association between caries and reduced cancer risk is real, the team suggests that one could regard the cariogenic bacteria as beneficial overall, with caries 'a form of collateral damage.' Therefore an appropriate strategy could be to target that effect specifically without aggressively targeting the bacteria. 'Antimicrobial treatment, vaccination, or gene therapy against cariogenic bacteria may lead to more harm than good in the long run.'"
The bacterial excretions (Score:5, Informative)
Re:The bacterial excretions (Score:5, Informative)
Raising PH level means less acidic. Acid excreted by these bacteria would decrease PH, not raising it.
PH less than 7 is acidic while PH greater than 7 is alkaline.
Whoa, slow down there! (Score:5, Informative)
"Once fluoride is incorporated into the teeth of children, the problem of dental infection by decay-causing bacteria is solved, because the pH required to cause decay in teeth that have fluoride included is never achieved by the bacteria."
It doesn't work that way. I am a dentist and can guarantee you that even fluoride treated teeth and teeth with systemic fluoride incorporation can and do get cavities. I drill and fill them all day every day. Fluoride is only one factor in keeping teeth healthy. You still have to brush, floss, maintain a healthy diet, etc.
Re:The bacterial excretions (Score:5, Informative)
The X-Ray dose is trivial...especially the digital versions, which use, I believe, six times less radiation than a normal non-digital version.
http://www.physics.isu.edu/radinf/dental.htm
2 or 3 mrem is the reported dose for a dentist X-Ray.
http://www.nrc.gov/about-nrc/radiation/around-us/doses-daily-lives.html
On average, Americans receive a radiation dose of about 0.62 rem (620 millirem) each year.
Re:FRAUD ALERT! JAMA again. (Score:2, Informative)
JAMA is a publication by healthcare professionals, for healthcare professionals. Not for the public. In fact, very little of what is published in the medical literature can be interpreted without a broad understanding of physiology, pathophysiology, research design, and biostatistics. Your points against JAMA Otolaryngology are all based off of fundamental misunderstandings due to deficiencies in those areas. Let me address them not in the order you've brought them up, but from the "bottom up" so we can build off of prior knowledge.
First off, study design. Many of your points concern deficiencies in the abstract. The abstract's function is to allow a physician to gauge interest in the article's contents without having to read the entire thing. They're written under a strict word limit and are often submitted to the journal before the final draft of the article is completed, rendering many of them inaccurate. Additionally, the journal does not need to state that this is "just a discovery of an association". This is self-evident by the study design, which is identified in the abstract as "case control". This means that it is a retrospective study, and, by definition, cannot prove causality.
Moving onto the slides, I cannot find a download link, so I cannot verify that they are correct. I can, however, verify that your understanding of dentistry is incomplete. Fluoridation is the process of converting the outer layer of your tooth enamel from a weaker, non-fluoridated form to a stronger form which incorporates fluoride ions. This change renders the outer layer of your teeth more resistant to (but not immune to) scratching, chipping, and dissolution at low pH (such as is produced by oral bacteria). Fluoridation is not a permanent process; like nearly all biological reactions, it is reversible, given time and liquid with which to dissolve extra fluoride ions. Your saliva is perfect for this. As such, humans need constant dental fluoridation. Fluoridated water goes a long way to providing this, but the process is easily overwhelmed by poor dental hygiene.
In addition, the "news article" against which you rail is another publication by and for doctors. Specifically, the article is intended as "Continuing Medical Education" (although I strongly doubt that it's accredited as such). Nowhere in the article is the discovery presented as causation. Nowhere in the article is a distinction between "link" or "association" or "correlation" and "causation" even necessary, given its target audience. In my opinion, the article provides a very brief and thorough overview of the article that helpfully highlights some of its major flaws--that it's single-center, retrospective, and was unable to control for confounding variables.
What your post does highlight is a huge issue regarding health information. In that there is quite a lot of it, and, despite being written in an approximation of normal English, many terms have connotations that lay people will not have the training to understand. When you add in a number of "health news reporters" without any medical background who write articles that are either materially false or easily misconstrued, you have a recipe for a system that the public does not trust. As of right now, there is a relative paucity of trustworthy health news for the general public. I urge you instead to speak with a doctor or pharmacist about the latest and greatest news so that you get the context required for interpreting the information.
Re:Whoa, slow down there! (Score:4, Informative)
There are a million possible explanations. Everyone is different. Caries is a function of personal habits, exposure to fluoride, both systemic and topical, your immune system, the anatomy of your teeth, diet, etc. There is no way to explain specifically why one person gets more cavities than another.
I hear patients tell me that they've never had problems with their teeth until they started going to the dentist. People seem to think that if there is nothing causing pain there is nothing wrong. That could not be further from the truth. I have extracted hundreds of teeth from people with mountain-dew mouth and meth mouth who have multiple teeth rotted down to the gum line. I always ask if any of those teeth ever hurt and frequently they tell me that those teeth never caused any discomfort at all. I don't know why, but it happens a lot. If lack of pain is the only measure of your own oral health I have two things to say to you: 1) go see a dentist anyway. 2) I wish you continued luck.
People say "Why should I go to the dentist- my teeth don't hurt. Every time I go there they want to take x-rays and drill holes in my teeth, and even pull some of them out, even though there is nothing wrong with them. I think it's just a racket to separate me from my money." So they don't go to the dentist and their conspiracy theory becomes a self-fulfilling prophecy. When they go to a dentist once every ten years they end up getting drilled and filled (if they are lucky) or worse.
Pay attention because I'm going to drop some knowledge on you: the lack of pain is NOT a reliable indicator of oral health, just as it is NOT a reliable indicator of health in general. Anyone who knows about the long term effects of high blood pressure or diabetes knows that both are seriously unhealthy conditions - ask someone with high blood pressure or diabetes if their illnesses cause them any pain.