Sugar, acid and teeth (2009) | Hacker News Reader

Sugar, acid and teeth (2009)

dbskeptic.com

165 pointsjondot102 comments

I wish he would have provided more explanation behind the dentist's algorithm. Here's an actual study measuring enamel loss, which seems much more definitive:

http://faculty.philau.edu/ashleyj/General%20Dentistry%20Arti...

Perhaps the most important snippet:

Regression analysis indicated no correlation between enamel dissolution and beverage pH (r = 0.477, p > 0.05); in addition, the enamel dissolution showed no difference (p > 0.05) between the regular and diet versions of cola and non-cola beverages from the same manufacturer (Fig. 2 and 3). It was noted that the enamel dissolution was similar for all cola drinks over the 14-day test period (approximately 3.0 mg/cm2).

And again:

The data suggest that enamel aggressivity is determined by beverage composition rather than by beverage pH.

Or how about experimental science? Get some human teeth (probably not difficult or expensive for a dentist), weigh them, plunk them in each liquid, let them sit for a week, see which ones lost the most mass.

Obviously scientific rigor would require several experiments to smooth out the variances in individual tooth quality and original composition, but it seems like that would come to a more definitive conclusion.

I agree with your sentiment, but a large factor in tooth decay is bacteria that live in your mouth: http://en.wikipedia.org/wiki/Dental_caries

This seems like what the article gets wrong as well. What you drink and eat impacts the environment in your mouth where bacteria flourish which in turn impacts tooth decay. There just isn't such a direct cause/effect relationship between pH/sugar and tooth decay, although they are certainly strongly correlated.

As a result, I'd take this article as a loose framework rather than a true scientific ranking.

Teeth continuously remineralize in living humans, so this experiment wouldn't tell us anything useful.

Do they? Even so, they will remineralize at the same rate regardless of the substance which dissolved them in the first place, right? (Ignoring, of course, that the ongoing presence of bacteria feeding on sugars may counteract the remineralization). The experiment would still demonstrate which substance destroys teeth the fastest.

Those bacteria you're ignoring are likely to be the key factor in this whole business, so it seems like a highly incorrect simplification.

I think the presence of saliva has a major effect on inhibiting tooth decay. I'm not sure how applicable in vitro experiments would be.

Exactly, hence the problem with allowing babies to sleep with a bottle. It's not the milk in the bottle that does the harm, it's the uneven saliva exposure in the mouth.

In general, people with good salivary coverage get less tooth decay. People with dry mouths, for whatever reason, get more. This isn't exactly an avant garde research topic.

While the dentist has impeccable credentials, she seems too reliant on anecdotes and personal observations, and insufficiently rigorous (to put it mildly) in justifying the mathematical model she proposes. The reasoning in this article is a little better than the old science-fair standby of dropping a tooth in a glass of Coke and gasping with horror when it's gone a week later, but not much.

It would give us a new hypothesis to test, and if it turns out to be wrong, it would tell us a lot about saliva, don't you think?

A human tooth submerged in Pepsi will actually dissolve completely in less than a week.

Is that true? I remember Mythbusters disproving the myth that it would dissolve a tooth overnight.

Perhaps a week is too much time.

http://www.snopes.com/cokelore/tooth.asp suggests that submerging teeth in any acidic substance (e.g. orange juice) will soften and eventually dissolve them. Since this does not adequately replicate conditions in the mouth, it would not be useful to determine how such substances affect enamel.

I don't see how "not adequately replicating mouth conditions" leads to "would not be useful to determine effect on enamel".

Yes, there will be significant differences between drinking Coke and soaking a tooth in Coke overnight. But that doesn't mean it won't provide a useful basis for comparison! Possibly even more useful than the arbitrary formula the author and dentist in the article came up with.

>But that doesn't mean it won't provide a useful basis for comparison!

Why bother? There are plenty of people out there who've been drinking coke for decades. All you need to do is compare their dental health to people who don't.

What useful basis does it provide?

p>0.05 does not mean that a correlation has been disproven, just that the authors are unable to reject the null hypothesis (potentially due to lack of statistical power).

Where "worst" is defined by a function of pH and sugar content pulled out of the air by a dentist.

Seems having only a dentist on hand for that "experiment" is akin to having a mechanic as your only expert for analyzing a car wreck? As the author even concedes, an abundance of anecdotes is not evidence.

Was it so hard to find a chemist way back in aught-9? (Go down to the nearest uni and find a chem major at least...)

The wide distribution of oversimplified, media-sanitized, pseudo-science is likely one of the affectations of Western culture that has kept it from progressing further for a solid 60 years--since television gave the ability for snake oil salesmen to multiply their effectiveness. The internet exponentially increased that ability.

How do you know the dentist pulled it out of thin air? A dentist would seem to have a decent likelihood of being familiar with the science.

If the dentist is being scientific, it's up to him to back up his claims about sugar and acid being the most (or only) important indicators for what's bad for teeth.

EDIT: For example, there's been some interesting work discussed here: http://wholehealthsource.blogspot.ca/2009/03/reversing-tooth...

If you do some googling, it's commonly accepted that both sugar and acid are bad for your teeth, with plenty of justification. Some of the reasons are even covered in the article.

You're correct in that their classification of "worst" only applies if sugar and acidity are the most important factors. But they're clearly a large factor in tooth decay, so measuring the contents of various liquids and comparing them to each other is instructive.

> But they're clearly a large factor in tooth decay

Maybe, maybe not. The in-vivo environment might have many significant differences than some in-vitro setup. What's the role of saliva? of bacteria? of genetics?

Don't underestimate the power of the telephone game (http://en.wikipedia.org/wiki/Chinese_whispers). You need to go back to primary sources. It's very common for papers in software engineering, for instance, to confuse qualitative statements from earlier papers with empirical results.

I was just suggesting that the dentist might be familiar with the best science we have directly or indirectly, not even that he was acting scientifically per se.

Their function 10^(5.5-pH) * (mg/cl sugar + 1) does seem to imply that sugar and acidity have a synergistic effect, where the +1 in the sugar term is a hack to keep the result from being 0 if the sugar is 0. This doesn't make sense, as a modest increase in sugar, say from 0 to 1 would double the result regardless of the pH.

What the equation says to me is that acidity sets the stage for tooth damage, but as bad as that is, once you start feeding the bacteria in that set stage, you are in real trouble.

However, the entire article is a hypothesis. It is a best guess by somebody with scientific knowledge, but there is no reason to believe the real formula shouldn't be 10^(5.5-ph)+10(mg/cl sugar) or something completely different.

However, my son and daughter both need a science fair project soon. I wonder if there is a way to formalize this a little.

How about the following:

1. Find a substance that is chemically tooth-like

2. Split it into predefined volumes (little cubes or spheres)

3. Add the beverage and saliva to the "tooth", wait a month, and measure the decrease in "tooth" volume.

4. Use regression to estimate the coefficients for sugar, pH, and whatever else.

You would be missing the bacteria, which are essential.

Their function also improves the results if the drink is more basic. A drink with a pH of 13 would have an amazing score on here.

If you normalize the pH above 5.5 since it has "little to no effect" things on the lower end of the results are better, with milk being worse than water, and chocolate milk being worse than milk.

This shows how bogus it is - you can put lots of sugar in a basic drink and it would score well.

The key point for me is why is concentration of sugar in mg/cl? Why not mg/l, or g/l, or oz/gallon? Each one would give a different answer, and all are equally justifiable. (There is also the weird idea that a decrease in pH of 1, which is 10 times the concentration of H+, would therefore be 10 times as bad.)

I just want to see a 2d plot. Sugar vs pH for all the drinks.

It's a very, very simplistic view of dental health. There's much more to it than what comes into contact with your teeth.

Interesting, but their choice of weighting of sugar and pH is not based on any evidence.

Also, would the amount of time that the drink is in contact with your teeth not have an impact? Perhaps wine would have more of an impact because you might keep it in your mouth longer, offset by the small likelihood you you drinking as much of it?

Similarly, I read something recently (no link, sorry) that stated something like the following (poorly paraphrased):

  Juice is fine to drink as it's generally healthy,
  but if you're going to drink it, do so quickly 
  instead of sipping on it for long periods.

The premise being exactly what you surmised, that chugging a small glass of OJ is much better for your teeth than sipping it and putting your teeth into contact with it for so much longer.

Juice is for most intents and purposes no healthier dan soda. It's mostly sugar and acid. The fact that said sugar and acid used to reside in a piece of fruit makes no difference at all.

If you want the health benefits of fruit, eat a piece of fruit.

I love the conviction with which you say that.

So, there is no difference between compounds that we've evolved to consume over millions of years, and ones which were designed in the last 30 to be as addictive and as cheap to make as possible?

While I do not claim that there is evidence of difference (I cannot provide any), it is unfounded to claim that there is none, whether based on some (inherently) limited study of effects, or just based on lack of knowledge otherwise.

To be clear, I'm NOT talking about "Honest to god freshly squeezed tropicana juice", which is stretching the definition of what "squeezed orange juice" means (In case you are not aware - they boil it in vacuum, which gives it a much longer storage and shelf life, but kills taste and probably also any nutritional value; flavor is later added with a market-specific artificial "flavor kit" before packaging to consumers).

I'm talking about actually taking an orange, squeezing that, and drinking it. Which should be the only acceptable definition for "orange juice", I think.

It may be what you consider the "acceptable definition" of fruit juice, but it is not the definition in common use.

Also, you are not evolutionarily adapted to eat compounds. You are evolutionarily adapted to eat foods. And fruit juice is not a food you are evolutionarily adapted to eat. It is very different, biologically, from eating an actual fruit.

For those who might be wondering, one such difference is the presence of fiber in fruit, but the lack of fiber in fruit juices.

As I've mentioned in a reply above, I accept the criticism. Grudgingly.

While it is not really comparable, I wonder if 50 years from now a study about the value of vegetables will use Pizza as an acceptable vegetable portion (because http://www.msnbc.msn.com/id/45306416/ns/health-diet_and_nutr... ) We laugh it this now, but 30 years from now, it might seem perfectly plausible to consider pizza a vegetable.

Freshly squeezed oranges are not what most people consume when they consume juice. A sterilized, overly processed concoction of fructose and acid, which, yes, originated in fruit, is.

By defining "fruit juice" to be something almost nobody ever consumes, then declaring the actual fruit juice people actually consume as being bad, it seems to me that you're agreeing with him while using language that pretends you're not.

Well, I accept the criticism.

I grew up knowing actual fresh squeezed orange juice as "orange juice", and everything else as "orange beverage" (well, an equivalent translation in my native language).

But I realize that, since I moved to the US, I haven't actually had anything that tastes like real Orange Juice. Regardless of what it says on the package or what the waiter says.

Well, there you go. Just different assumptions and experiences.

I believe that you're still better off just eating the orange rather than drinking the juice. But I don't doubt that what you see as proper juice is way better than the stuff you find in stores.

Your entire post is nothing but fallacies. You don't evolve to do anything. And you didn't evolve in the presence of orange juice, oranges didn't exist. And it doesn't matter, because that is just the naturalistic fallacy. Something being "natural" doesn't make it good, and something being "artificial" doesn't make it bad. We did not evolve with modern tooth cleaning equipment or flouride treatments either, but those are still beneficial to our teeth.

There is absolutely no evidence to support the notion that pop is any worse for you than a fruit juice of similar acidity and caloric content.

It would help to read what I was replying to, and what I was actually replying:

GP said: "Juice is for most intents and purposes no healthier dan soda."

You said: "There is absolutely no evidence to support the notion that pop is any worse for you than a fruit juice of similar acidity and caloric content."

I said: "There is no evidence of difference", which is exactly what you said.

Can you spot the difference between yourself and GP, though? One is an assertion; the other is an assertion of no evidence against said assertion.

> "You don't evolve to do anything"

We clearly don't speak the same language. What do you mean by that? I breathe; did I not evolve to breathe?

Where did I state that everything "natural is good" or that anything "artificial is bad"? Who and what are you arguing with?

I did read it, you are trying to pretend you said something other than what you post says. You made all the fallacious claims I pointed out.

As for evolution, no you did not evolve to do anything. Evolution is a process, it does not have goals. It is not aiming to get somewhere, or accomplish something. Which is why claiming you "evolved to eat X" is nonsense. Your ancestors evolved the ability to gain nutrition from X, that doesn't mean X is good for you. It means in prehistoric times, the short term gain from being able to gain nutrition from X was greater than any downsides to it (it could cause cancer 100% guaranteed, but if it lets you survive in the short term long enough to reproduce and rear offspring, it will still end up selected for).

> I did read it, you are trying to pretend you said something other than what you post says. You made all the fallacious claims I pointed out.

Clearly we are NOT speaking the same language.

> As for evolution, no you did not evolve to do anything

Clearly, again, we are NOT speaking the same language. You react as if I said "I evolved with the goal of breathing", which is a possible, but improbable, interpretation of what I wrote. I meant "My kind has evolved the ability and necessity to breathe", for which "I evolved to breathe is" a shorthand, acceptable where I live.

And if you can point out how my statement that "I do not claim that there is evidence of difference (I cannot provide any)" can be construed as anything but "There is no evidence of difference" (that I know of), I would be grateful. Because you are calling me a liar in not so many words, and I don't like that in general (but I don't really care either, given we're both anonymous)

You are right, we are not speaking the same language. You are speaking "I want to argue about nothing for no reason", and I am speaking english. Go read the thread again, I did not make any claims other than that your post was full of fallacies. I didn't say "you said juice is healthy". You are accusing me of exactly what you are doing. Grow up.

Most juice is so heavily processed it should be labelled as soda.

It may be better for your teeth, but I wonder if chugging it will spike your insulin more.

That was kind of the same question I had when I read it, but I came to the (completely uninformed) conclusion that probably, the body's absorption rate was self-metering enough that it probably wouldn't make a difference drinking it all at once vs. drinking it over a 20 minute period.

I have absolutely no evidence whatsoever to support this however, so who knows?

Fructose is metabolised by the liver, which may only be able to handle so much at a time without negative effects. Raw fruit is digested more slowly than juice due its fibre content, so drinking juice slowly could be worse for your teeth but better for your liver.

Even modern raw fruit are significantly larger and sweeter than a few hundred years ago, so maybe we should just stick to berries.

"To mitigate the effects of pop consumption, only consume it with meals. Brush soon after eating or drinking anything besides water (including milk or juices)."

Brushing soon after drinking or eating something sugary is not a good idea. Best to wait around 30 minutes and let your body clean your teeth during that time, after the 30 minutes manually clean!

http://well.blogs.nytimes.com/2012/05/21/really-never-brush-...

http://www.hindustantimes.com/Entertainment/Wellness/Brushin...

I have deep grooves in my teeth right above my gums on both sides of my mouth from drinking 3-6 cokes a day for 10+ years. For some reason, I have a habit of swishing the drinks on the bottom of my mouth and I think this is the reason why my teeth are so jacked up. In the past year, I've largely stopped drinking Coke, partly because of this, and because of the other health problems associated with drinking so much soft drinks. I've switched to water and have a sugary drink maybe once or twice a week.

Besides being bad for your teeth it's a nightmare on your body. That insulin dump from the onslaught of sugar will make you much more likely to develop diabetes, and some studies have shown a long-term metabolic effect where your body prefers sugars for energy instead of fats. That and the empty calories will lop-side your diet and make it harder to lose weight or gain muscle.

There are lots of ways you can drink something tasty and not have such a huge impact on your body. Sometimes i'll buy a two-liter of green tea ginger ale or cranberry juice, and make a 50/50 or 25/75 mix of the drink and tap water.

You can also just cold-brew tea or coffee and mix in a little sweetener or other flavor to change it up. It's cheaper than soda and (after you stop drinking soda every day) tastes much better because you're not getting hit over the head with truckloads of sugars. Ask a European about how sweet all our foods and drinks are.

Unsweetened tea and coffee are definitely your best bets next to plain tap water for generally healthy drinks. Though I have found that drinking loads of black tea stains your teeth (it was cleanable), and switched to green tea.

http://www.hsph.harvard.edu/nutritionsource/healthy-drinks/

I 100% agree. Actually I have done almost exactly that, switched to tea, or ice tea. I'm not completely off the sugary drinks, but I'll drink things like Honest Tea with a lot less sugar than Coke, or just plain Tea.

The thing I'm actually most worried about is pancreatic cancer. I'm not even sure if there's a link between that and soft drinks, but I read one study where having 2-3 soft drinks a week doubled your risk of getting it. Well I was having 20 a week, which scared the crap out of me. And more and more people appear to be contracting and dying of it, so it's my secret fear.

For sweetness, try rotating between non-fructuse sweeteners. like saccharin, aspartame, stevia, etc. I also find that Coke Zero is a nice way to cut down on sugar but still keep the Coke taste, and it's a lot less acidic than Diet Coke. However I don't find vending machines stocking it as often as I'd like. That's assuming you are not buying into the aspartame myths. I've got diabetes in my family, so to me the risks of sugar far outweighs the less than slight risk of aspartame.

Or, you know, stop drinking sweet things =) I know that's heretical in our society, but once you cut out sweet things your palate will change and you'll find things like unsweetened teas (cold Oolong is fucking amazing) and juice/water mixes are cheap, simple, tasty and healthy.

I love unsweetened iced tea and drink it as often as I can get it when I'm visiting home in the States, but it's so hard to get good iced tea in Europe, and since it's hard to keep enough ice on hand, it's a pain to try and make it here as well. So I end up drinking stuff like Pepsi Max (Can't get Diet Pepsi in Norway) or other diet sodas.

Actually I can't eat aspartame because it severely upsets my stomach, so I need to avoid it completely. Even things like chewing gum with aspartame cause my stomach to get really upset. I think the best solution is simply not eat as much sugar as possible. I was on South Beach diet several years ago, and I actually lost 20 lbs in 5 months, so maybe I will do something similar.

In terms of acidity it's the other way around. From the article:

"say you have two liquids, like Diet Coke and Coke Zero. Diet Coke has a pH of 4. Coke Zero has a pH of 3. Since pH measurements are logarithmic, this means that Coke Zero is ten times more acidic than Diet Coke."

Did you read the article? Coke zero is ten times more acidic than diet coke.

Screw the cancer. Stop drinking soda because it's just not tasty.

There's a whole world of drinks not found in your local vending machine that are crazy tasty and healthy for you. Fruit/vegetable-infused water, iced teas and blends, juice seltzer, kombucha, iced coffee, and about a billion delicious latin juice drinks with fruit that only people who speak spanish know about (my fav's probably Guanabana, though watered down a bit).

Nightmare, onslaught, much more likely, lop-side, huge impact, truckloads of sugar... How can you use such scary descriptions without any giving any evidence backing up what you're saying?

This is my favorite article describing the effects of a Coke on the body: https://www.nutritionresearchcenter.org/healthnews/what-happ...

This article has some good explanation of the health detriments too: http://health.yahoo.net/experts/drmao/what-soft-drinks-are-d...

This should not be so much surprise to anyone really. It's pretty widely known that sugar and acids are bad for your teeth. The degree to which any drink with these contributes to dental damage is probably more complicated but everyone knows that its best to drink water. Not only will it not ruin your teeth but it will also not make you fat, like sodas and juice boxes.

With "skeptic" in the name, I was expecting much, much better. It's a pretty bland application of some rule-of-thumb (perhaps, dogmatic) beliefs about tooth decay, which doesn't hold up to reality.

One of the problems which comes to mind is that mouth wash has NEVER proven effective in preventing tooth decay (and companies that make Scope, Listerene and others would really LOVE to be able to say that it does). Meanwhile, this article blindly asserts that they will work quite well.

This issue throws every other claim into doubt, too, since the bacteria is claimed be be the sole cause of decay, and a mouth wash certainly could kill-off bacteria in the mouth. It seems tooth decay is a far more complex activity than the model used in this discussion.

I never drink any sugary juices or candy. Eat lots of fruits and veggies, also bread, milk and nuts.

And I have terrible tooth decay.

Seems a bit silly to compare pHs of various junk foods. Drinking a better pH won't make much difference. The problem is a tad more complicated.

I had terrible tooth decay when I was younger (I have 16 fillings from ages 10-20). And then, all of a sudden - nothing. I haven't had a hole or a problem since (except for a filling that broke and had to be replaced). There was nothing that I'm aware of that I changed around that time -- I stopped drinking sodas and eating junk food around age 30.

But I have recently read claims (and testimonials) that what you need for healthy teeth is Vitamin D (make sure you take it in the morning if you do!) and Vitamin K2, see e.g. http://www.thedentalessentials.com/The_role_of_vitamin_k2_on... ; If you find this interesting, you'll find a lot more similar stuff on the bulletproof executive forums.

There's some effort underway to develop a vaccine against dental caries: http://en.wikipedia.org/wiki/Caries_vaccine

Indeed, there are some very exciting prospects here. The replacement therapy seems most promising. I developed a number of cavities out of the blue after I began aggressively using mouthwash - my theory is that I had a mostly benevolent strain of bacteria and accidentally killed them off, and they were eventually replaced with a nastier strain. If a harmless strain could be administered through vaccine or chewing gum, the societal effects would be enormous. Seems like the largest problem left (as usual, sadly) is getting it out of the lab.

My uncle who is a dentist told me i got loads of cavities from gatorade. His rationale aside from the high sugar content was that because I was exercising, my mouth was drying out w/the gatorade residue in it. So the sugars eat away at your teeth faster. So there is that factor to weigh in as well (how your mouth is reacting at the time of the liquid consumption, or post consumption residue).

One hears that Bulimia and certain drug addictions (Crack, Meth) are very bad for your teeth. Bulimia because of the strong acid, and drugs because they interfere with the mouth's self-cleaning instinct.

I'd guess the best teeth live in a mouth with: 1. Active high-volume saliva glands 2. A population of healthy bacteria

How do you encourage that?

The reason why amphetamines are bad for your teeth is that they prevent your mouth from making saliva, which allows bacteria to multiply and causes other bad things to happen as well. Obviously it's probably not a good idea to be using meth in the first place, but if you're going to use any sort of drug that causes dry mouth then at the very least you should brush, floss, and use mouthwash and flouride rinse beforehand.

How about encourage them not to become crack heads or bulimics in the first place? It's a strategy that probably has benefits beyond mere dental health.

Hm, but what about the effect of the bacteria consuming said drinks; surely this will change the results ?

Bacteria vs. Human body^1.

1. Specifically, teeth and saliva, but you must always consider the whole organism.

Drink soda pop --> Advantage, Bacteria.

Don't drink soda pop. --> What do you think?

Bacteria need acidic conditions and they are happy to have plenty of sugar. Preserving your teeth means giving your body the best possible chance against bacteria, slowing the process of decay as much as you can. But in the end, on every front, bacteria will always win. It's just a matter of time. If they don't consume you while you're alive, they will after you're dead.

With respect to tooth decay, drinking soft drinks surely helps bacteria, not the human body. But then, maybe people derive other benefits from drinking these concoctions. (Jolt?) Maybe preserving their teeth is not their number one priority?

Factoid: George Washington had wooden teeth?

Interested in hearing what people think of Xylitol and its positive effects on saliva pH.

Xylitol's major positive effects on teeth health come from a different path: The bacteria responsible for cavities will try to eat it (cause it's close enough to sugar) but fail to digest it (cause it isn't), which will interfere with their ability to prosper and even kill them.

(Unfortunately, that's also true for dogs: DO NOT feed your dog xylitol. It is toxic for them: two xylitol-swettened gums are potentially enough to kill a small dog, and cause irreversible damage to larger dogs!)

https://en.wikipedia.org/wiki/Xylitol is a treasure trove

That sounds like something I don't want to be eating either, if it's so toxic to both bacteria and fairly similar mammals. Have there been any long term xylitol studies? It seems likely that it would screw with the bacteria in one's gut.

I don't know specifically about bacteria in one's gut, and hadn't thought of that. However, studies of xylitol in both humans and rats all show overwhelming positive (and mostly unexpected) results related to immunity to diseases like respiratory infections and ear infections.

> something I don't want to be eating either, if it's so toxic to both bacteria and fairly similar mammals.

FYI: Chocolate is toxic to dogs as well; a 70% chocolate bar can kill a small dog. Are you going to abstain from chocolate and recommend everyone else does too?

Also: some humans are deathly allergic to nuts, and others to strawberries, and yet others to wheat gluten. These people are a lot closer to you genetically than a dog.

Enough research has been done on xylitol to deem it safe for human use -- much more so than e.g. sucralose (Splenda), acesulfame-K (SweetOne), Aspartame (NutraSweet) and High Fructose Corn Syrup. And while Xylitol does not form naturally, it is a sugar alochol like e.g. Sorbitol (also found in plums and apples), and shares the vast majority of its properties.

Really, do read the wikipedia entry.

I've never understood if sugar affects gum disease. Does anyone know? Does the gum disease bacteria eat sugar or directly eat your teeth and gums?

I tried looking it up once but I only found information about sugar and cavities.

Bacteria consume sugar, which produces acid as a waste-product, which erodes enamel. Gum disease is primarily an inflammatory response to the presence of external irritants like dental plaque (which contains bacteria as well).

So there's no specific gum disease bacteria? It's just the same bacteria that causes cavities?

According to Feng & Weinberg:

Approximately 500 bacterial species reside in the oral cavity. Of these, 415 species are estimated to be present in subgingival plaque. Specifically:

"A. actinomycetemcomitans has been strongly implicated in localized aggressive (juvenile) periodontitis Likewise, bacteria such as P. gingivalis, A. actinomycetemcomitans, Tannerella forsythia (formerly, Bacteroides forsythus), Treponema denticola, and Eikenella corrodens have been associated with chronic (adult) periodontitis."

Ref: http://www.perioimplantelsalvador.com/Informacion/bibliograf...

To couple pH with 'badness', you need to couple it with volume. It takes less effort to neutralize 1L of pH3 stuff than 10L of pH4 stuff.

From a very basic investigation by myself, I have found whiskey and water to be the alcoholic drink that's the least acidic.

As a child, my dentist also warned me about Mountain Dew and gave a specific reason - the presence of ethylenediaminetetraacetic acid (EDTA), used as a stabilizer.

His theory was that it would chelate the calcium out of your tooth enamel.

Sounds like a bit of dentist lore that gets passed around. Maybe because they use EDTA during root canals to prep the area.

Have there been any studies on whether drinking with a straw is better than drinking from a cup/bottle?

I can't see how second best sorbitol and the best being Xylitol are any better than sugar they're sugar alcohols which have the effects of a laxitive.

How about just not eating so much sugar, and if you're diabetic try stevia that's what my mother, a diabetic, chooses.

So a cookie should be much worse than any sugary drink.

Basically, if you eat more than 0 sweets per day, it seems ridiculous to worry about sugary drinks.

If you get a raspberry seed stuck between your teeth, it should be much worse than a sugary drink.

Is there some coating effect I'm missing?

Hmm, this makes me wonder; should a low carb diet help cure gum disease and prevent cavities since you're providing so little sugar to the bacteria?

In fact do you need to brush and floss when on a low carb diet?

Has this been studied?

I didn't get the impression they looked at serving size. In other words, the Merlot's average serving size is smaller than that of the Guiness, even though the latter is "better".

I wonder how much serving size would even matter? I'm told the damage comes after the drink really, when your teeth sit around covered in it.

I'm sure it'd make some difference, it takes longer to drink a pint than a shot there'll be a bigger concentration there during those initial minutes, but I doubt it'd be linearly proportional.

I'd guessed a red-wine. My dentist certainly goes on about my drinking booze more than me downing Ribena by the pint. I wonder if alcohol can have some unmeasured effect apart from sugar content and PH.

If you must drinks harmful to teeth, It would make sense to me to use a straw, and put the straw deep in you mouth so that the liquid does not come in contact with the teeth.

So where do coffee, espresso, & teas (black, green) fit into his Harm Matrix?

Depends how much sugar you put into them.

Root beer is the best soda (pop) for your teeth because it isn't acidic.

My dentist explained it this way: Bacteria eats sugar and pees acid.

Wow, I never realized Diet Coke was less acidic than Diet Dr Pepper.

Thats it. I am switching to Spartan Lower 1/2% milk

Genetics.

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