Slashdot Mirror
Tooth Cavities May Protect Against Cancer
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.'"
or people who fail to take care of their teeth happen to do something else beneficial. I don't see a cause -> effect mapping between these observations.
The research suggests that the excretions of the bacteria and the bodies reaction to that are the cause -> effect mapping. However, your suggestion that toothpaste may have unknown carcinogenic properties could be just as valid.
I was promised a flying car. Where is my flying car?
... Or is a common ingredient in toothpaste a carcinogen?
I agree. It could be the opposite, that whatever prevents cancer causes tooth decay. Or, that there is an accidental association caused by some effect not studied, like accidental, unknown bias in the selection of patients to study.
This seems to be intentional fraud by JAMA, the Journal of the American Medical Association. The abstract of the JAMA Otolaryngology -- Head and Neck Surgery article calls the effect an "association".
The abstract should carry a warning something like this: "This is just a discovery of an association. No claim is made that one effect causes the other."
Instead, "MedPage Today, LLC and the Perelman School of Medicine at the University of Pennsylvania" published the "association" as cause and effect: "Dental Caries May Protect Against Cancer". In my opinion, that is fraud of a kind that is engaged in again and again. JAMA knows this occurs and does nothing to stop it. Instead, the public is encouraged to believe that something far more important than an "association" has been discovered. In effect, JAMA is allowing dishonest advertising of the medical and dental professions. JAMA seems to be an aggressive organization that sometimes promotes financial success for doctors against the interests of the public.
Also, the PDF of the slides is misleading. My understanding is that fluoridation means monitoring the levels of fluoride and adding fluoride so that the amount in the water is sufficient, as a child's permanent teeth are growing, to prevent tooth decay over the child's entire young and adult life. 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. So, the slides are talking about cures for problems that occur only in people who did not have fluoridated water in childhood. I have friends who say that fluoridation had that effect in themselves and their children.
On Wikipedia, it's written that head and neck cancer
is strongly associated with certain environmental and lifestyle risk factors
The article says,
Other limitations included lack of data on potential confounders such as patients' diet and socioeconomic status
Isn't the work conditions one of the biggest things you look at in a cancer study? In the case of dental study, also diet.
Among 399 patients with head and neck cancer, current or previous dental caries were significantly less common than in 221 individuals without a cancer diagnosis,
Something like smoking or chewing tobacco would increase cancer risks but lower cavities.
Even if this mechanism is real, cariogenic bacteria can only be beneficial if you're certain that tooth decay and the associated problems (abscesses, sepsis, etc.) won't kill you off before you get a chance to get cancer in the first place. It's all fine if you have access to a reasonably good dentist, like a third of the world or so in the past century, but otherwise...just ask Ramesses II.
Ezekiel 23:20
Screw you colgate ! I win.
:) (they prolly cause cancer)
Ms Marsh, suck eggs
Another question: Does Hugh Pickens get paid for promoting this Slashdot article? Did someone at Slashdot get paid for including it?
How many of these people still have their tonsils? I recall reading in one of the journals, probably on arxxiv and phys.org too, that there is some supporting data showing essentially a second immune system just for the mouth.
No link 'cause my google-fu is coffee fueled.
Ever notice that Cobra Commander sounds an awful lot like Star scream?
Observational Studies are no where near being true nor scientific. Sure they're part of the scientific process but they aren't themselves scientific at all. Clinical studies are required. You could just as easily say that Eating less sugar, thus having less tooth cavities, may protect against cancer, or how about brushing your teeth more often may reduces the risk of getting cancer. Please, for f**ks sake - stop taking shit out of context and drawing up conclusions. Has everyone forgot about the Nurses' Health Study recommending Estrogen to reduce heart disease? That turned out fantastic didn't it? Some clinical studies were discontinued since those taking Estrogen had an 40% increased risk of heart disease. Yet pills were sold and recommended by doctors based on Observational Studies. Turns out Natural Estrogen is fine and beneficial, particularly in the early stages of menopause. Emphasis on NATURAL Estrogen. Let's also not forget that this Cavity Cancer relationship study is conducted by JAMA. The same journal that published a similarly biased observational study on Estrogen (Heart and Estrogen-Progestin Replacement Study (HERS)) in the 1990s giving buzz to the Estrogen pills that were in 2002, clinically proven, to be completely false.
It may also be that people who take good care of their teeth, which includes regular dental checkups end up with more x-rays and more exposure to variety of viruses or bacteria which may be carcinogenic (such as HPV, cold sores). Another potential factor is carcinogenicity of the tooth care products, such as toothpastes and mouthwashes. These are couple possibilities that one wouldn't expect research by 'cavity industry' to consider.
Or, people with better dental hygiene and less cavities go with much more frequency to dentists, who nowadays won't touch you, even for simple cleaning, without taking X-rays.
The hill folk in Deliverance were toothless and playing banjos. Maybe country music prevents cancer.
"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.
Ah! The old conspiracy theory of dentistry!
I can assure you, there is plenty of work for dentists without anyone having to try to promote cariogenic behavior. In fact, it is usually dentists who promote fluoridation of water as a preventive measure.
Oh wait, I know, fluoridation of water is some sort of conspiracy too...
haven't read TFA, but could also mean those who get their carries fixed have more bitewing x-rays, which increases radiation to the head.
Because radiation prevents cancer???
He's saying that people who go to the dentist regularly (to get some cavities fixed) get fewer cavities overall thanks to better care, but they also get more dental X-rays. The amount of radiation in a dental X-ray is super-small and generally not considered a cancer risk; however, there's been growing use of Dental CT scans, which actually require a substantial dose to obtain.
Yes, they would need to account for extra dental care. It's also possible that people with fewer cavities see the dentist MORE often - that is, they take care of their teeth. This would make them more likely to floss, get regular cleanings, have tartar removed, get exposure to fluoride and toothpaste, and have regular x-rays. I'd bet this is an older population getting the cancers, so really we might be controlling for things they were exposed to years ago.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
IINAD, but I seem to recall a study showing the tradeoff between people with acidic mouths and people with more basic mouths. The acidic mouths are more amenable to tooth decay, but less susceptible to tartar buildup and gum disease. The basic mouths tend to get fewer cavities, but they get more tartar and are more likely to see gum disease. Gum disease is inflammation, and inflammation gets tied to cancer.
On the other hand, they controlled for very little in this study, it would seem. Fluoride, x-rays, frequency of dental visits, etc.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
Are smokers likely to go in for more teeth cleaning and/or whitening treatments to remedy ugly teeth? Do they brush more to get rid of stains? That might explain the whole thing.
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?