Does Soda Really Rot Your Teeth? And Make You Fat? Surprise…(or Not!)

Sometimes health research dazzles us with stunning new insights and novel correlations that crack open unimagined vistas. The headlines blare unusual, creative connections, showing us things we’d never even suspected before.

Those are rare days for science.

Much of the time, people in labs at the bench or crunching numbers in front of a screen are doing what the Discussion section of most published articles suggest: They are following up on previous research, because “more research is needed.” They’re adding to what we already suspect (or know), helping to clarify mechanisms of action, strengthening the ways we slice and dice data sets, or confirming already-established correlations. Especially as we bring all of the subtleties of genomics to medicine, expanding our basic knowledge base is as important as ever.

That’s why, even when we get a result we were expecting, it’s a win.

Confirming what we think we know (or potentially disconfirming all or parts of it) is just as much a part of the scientific research-and-development cycle as discovery. Each new well-designed, peer-reviewed, controlled study improves the process of how we test, refine, iterate, and ultimately use science to come up with pharmaceutical treatments and cures.

The latest “common sense” study adds heft to the longstanding cautionary words of mothers, grandmothers, aunties and dentists alike: Sugary soda makes you fat and rots your teeth. (Stop me if you’ve heard this one before.)

The Study: Analyzing Tooth Erosion in 3,500+ Patients & Soda Consumption

In the October 2019 publication of the online journal Clinical Oral Investigations, researchers reported findings that largely aligned with what “folk wisdom” has been telling oral health care practitioners for decades: High rates of consumption of sugar-sweetened, acidic beverages (aka soft drinks, soda, pop, or even sodapop, depending on which part of North America you live in) is a recipe for irreversible tooth wear–and is strongly correlated with obesity rates.

To arrive at these conclusions, researchers examined data from the 2003-2004 National Health and Nutrition Examination Survey, which relies on self-reports and recall of past consumption. Study participants were selected based on weighted demographic factors; They then followed up with dental exams of 40 surfaces (using a standardized TWI, or Tooth Wear Index). Selected representative individuals about their rates of beverage consumption in particular:

  • Sugar-sweetened acidic (SSA) drinks: Sugar-sweetened soda.
  • Sugar-sweetened non-acidic (SSNA) drinks: Sugar-sweetened coffee, tea, or milk-based beverages.
  • Non-sweetened acidic (NSA) drinks: Diet sodas and 100% fruit juices.
  • Non-sweetened non-acidic drinks (NSNNA): Unsweetened or artificially sweetened coffee, tea, or milk-based beverages.

While the findings were not exactly a surprise, they offered useful, evidence-based science to help arm dentists and hygienists with oral care reasons to caution against sugared soft drink consumption as well as solid medical correlations as well.

In those with tooth wear, the number of surfaces affected was 1.40 (95% CI…) times higher per additional SSA drink consumed per day. On the other hand, the number of surfaces with moderate-to-severe tooth wear was 17% (…95 CI…) lower per additional NSSNA drinks consumed per day. These two associations were slightly attenuated but remained significant after further adjustment for other types of drinks.”

In plain English? This study suggests people who drink sugary acidic beverages are placing more of their tooth surfaces at risk of enamel loss and erosion. 1.4 times as many surfaces, on average. On the other hand, those who drink more unsweetened, non-acidic drinks (like water, unsweetened coffee & tea, and milk) may be counteracting the effects of sugary, acidic beverages–you might think of those neutralizing drinks as functional mouthwashes to give teeth and oral tissues a good cleansing after the consumption of all that corrosive sugar and acid.

And from a medical perspective, the case against sweetened acidic beverages was even more solid. Sugary, acidic beverage drinkers were at a statistically increased risk for obesity–also correlated with tooth wear–and as we are learning in some of those more dazzling and unexpected study results, even diet soda can cause metabolic dysfunction and insulin spikes.


  1. Thanks for the info. I am going to recommend you for our dental society meetings in Toledo,Ohio!

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