Wednesday, February 25, 2009

The Decaying Teeth of Endurance Athletes (Guest Blogger Dr. Larry Dunlap)

My dentist friends tell me that they are seeing notably poor dental conditions in their patients who are endurance athletes. There are no scientific studies proving this situation but there are very good scientific reasons to suspect that their observations are true. The relatively poorer teeth of Americans in general are due predominantly to the exposure of the teeth to sugar and acidic pH. The worst teeth are seen in children who are put to sleep at night with a bottle of sugar containing beverage and have frequent access to similar beverages during the day. Some of these children lose all of their baby teeth to decay before they reach school age.

There are numerous well documented medical studies that show the deleterious affect of soft drinks on dental enamel. Non-cola beverages fared worst and dental problems were greatly accelerated by both regular and dietetic drinks, though the absence of sugar lessened decay. Recently sports drinks have been added to the studies with the surprising finding that they result in enamel deterioration equal to or worse than the non-cola beverages! Several different mechanisms are at work but the main problem is that almost all of these products contain phosphoric or citric acid. Other organic acids such as malic and tartaric are often present as well. These acids are very erosive to dental enamel due to their ability to chelate calcium. They are efficient buffers and keep oral pH well below the optimal salivary pH of 6.5 to 7.5. The threshold level for the development of dental caries is below Ph 5.5. Enamel demineralization occurs with prolonged exposure to lower pH or frequent cycling between optimal pH to below the threshold value. Sugar content facilitates bacterial proliferation which, in turn, promotes plaque and potential gingival inflammation at the gum line. Sports drinks and soft drinks are just not healthy for our teeth

If Darwin were alive today he would probably comment that we evolved as omnivores with infrequent fluid intake. Nothing in our dental design could anticipate the ability to sip an acidic sweet beverage multiple times during the day as well as at meal times.

Unfortunately everything in our training manuals tells us that we need to have fluids and calories on a regular basis during endurance exercise. These practices also have been scientifically documented and most of us can personally vouch for their validity. Who hasn’t experienced “hitting the wall” when failing to take in adequate replacement nutrients and/or electrolytes. Our healthy endurance habits however prove to be very unhealthy for our teeth. We are doing exactly what mothers are told not to allow their children to do which is to frequently ingest an acidic, sugar containing beverage. We may even swish these beverages around in our dry mouths in an effort to rehydrate the oral mucosa which at the same time insures an optimal bad environment for our teeth.

So far attempts to alter energy drinks with calcium and other elements that would prevent deterioration of tooth enamel have been generally unsuccessful. We are stuck with using products that are bad for our teeth. The choice here then becomes how to use them most effectively.

It turns out there are ways to drink which are going to be helpful in avoiding this degradation of tooth enamel. We need to drink rapidly and attempt not to bathe the teeth in the process. Most importantly, we can follow ingestion of any sugar containing beverage with a rinse of normal water. Our saliva brings the teeth back to a neutral pH which is healthy for the enamel. Calories and electrolytes can also be ingested as capsules which, with adequate water, provide similar physiological resuscitation without creating a bad environment for the teeth. Lastly, of course, we can see our dentist regularly and can consider fluoride treatments or application of a polymer-based protective resin to give our dental enamel an enhanced barrier against the ravages of beverages containing acids and sugar.

Consider that you are telling your great-grandchildren about the epic physical achievements of your youth. Won’t those children be more impressed when the words come from between teeth that you don’t have to take out at night? Endurance runners with their physiological needs are put in a position where their rehydration habits can have a devastating long term affect on the teeth that may initially be subtle and not fully noticeable for 5-l0 years. To counteract these factors an endurance athlete has to be particularly good about following the rules learned in grade school. Floss frequently, brush after meals and use a fluoride containing dentifrice. Drink sugar containing beverages in a way that minimizes contact with the teeth and follow them with a cleansing rinse of tap water. Be aware of these subtle subversive processes that may be a long term threat to your chewing and your smile.

Larry Dunlap, MD

[Dr. Dunlap is a marathoner and ultramarathon volunteer who also happens to be my Dad; he will be running the Boston Marathon this April!]


  1. Great article, Scott (and Larry).
    I guess good old H2O is still the safest bet :-)

    Say, is that a non-cola beverage that your dad is drinking in the picture?

  2. Thanks for the insights Larry.

    "Unfortunately everything in our training manuals tells us that we need to have fluids and calories on a regular basis during endurance exercise"

    Herein lies the crux. Before the early 80's when there were no specialist sports drinks, runners did just fine on water. With the advent of these drinks it is of course in the marketers best interest to convince the running pubic that it is crucial you have a steady supply of sports drink for your workouts. "Don't bonk" their ads say. Articles in running magazines generally support the same message.

    I don't buy it. I believe it's better to train you body to become an endurance machine with water-only (+ S-caps/endurolytes etc. on hot days) and judiciously use gels and sport drinks for those big (and long) races. I also believe that bonking during training is really good once in a while.

    Have you also noticed how the non-athletic public has bought into using these sports drinks as their primary beverage also?

    Cheers, Paul

  3. This is a useful post, nice of you to give us all a heads up.

    I've got to wonder though, specifically what sort of "sports drinks" are we talking about here? Is it the Gatorade Rain and Vitamin Water that I love, or more the Red Bull style sugar and carbonated power shot stuff?

    A bit of clarification would be even more helpful.

  4. Great article! What about Nuun? It has citric acid but no sugar and contains calcium. Maybe the lesser of the evils? (yes I'm a Nuun fan :)

  5. I am a firm believer in water only during training runs (+ s-caps when it's hot) and then during long races I drink coconut water which contains plenty of potassium, sodium, and NATURAL sugars as opposed to altered sugars in sports drinks.

  6. Like the others who posted comments, I think this was a great post; add your Dad as a regular feature.

    I use HEED form Hammer Nutrition. It's sweetened with stevia (not sugar), contains no acids, and no "ose" (glucose, dextrose, sucrose, etc.) It's been good to me on my long runs and I think it's natural enough to not upset the delicate ph of my mouth. Have you tried it? Thoughts?

  7. When I first started running many moons ago, there wasn't the emphasis on sports drinks, and my philosophy was to drink only a bit of water as needed. Worked fine for marathons- I only bonked once and that was most likely due to undertraining. Like so much of the rest of our diet now, sportsdrinks have become ubiquitous because of marketing, not because they are essential. see the thorough discussion at . (They have a whole series on the subject). As for carbohydrates, these guys have a very interesting discussion about fat burning as a preferred fuel for superior performance see I've seen similar discussions elsewhere too. So I agree with others here that drinking water to thirst is probably best most of the time, and you need to supplement with salts and sugars only occasionally.

    Nowadays I can get tired or nauseous if I go more than 3 hours or so without fuel, but protein and salt seems to do the trick (chicken broth or slice of turkey goes down well). David prefers coconut milk and whey protein as a sports drink and doesn't use carbs at all any more.

    Since we've cut our carb consumption in general, my dentist raves about how great my gums look. (Weird think to say I know.) Weston Price (a dentist) wrote about the superior dental health of people eating their traditional diets (low in sugar and carbs usually).

    Thanks for the posting!

  8. I'm a water and coconut juice guy myself (and do love the Nuun Kona Cola flavor). It's less a teeth thing for me, and more that I the mix drinks don't sit well in my stomach, particularly in the heat. Gels and real food are fine. I am a sucker for flat Coke during a race, which my dentist certainly wouldn't like. Perhaps if I brush every 20 miles? ;-)


  9. Hey Scott try this sports drink that doesn't have sugar...has great taste and works...I got it from Brendan Brazier's book call the Thrive Diet...

    juice of 1/2 lemon
    juice of 1/2 lime
    3 dates
    2 cups water or 1 cup water and one cup coconut water
    1 tbsp agave nectar
    1 tsp coconut oil
    sea salt to taste

    put all in a blender and there you have it...will stay for 3 days

    Adam J. Ulrey

  10. Maybe aid stations should have toothpaste and toothbrushes handy.

    Sarah, Wendell, you reading this?

    Cheers, Paul :-)

  11. Scott, your blog was instrumental in getting me trail running back in 2003, even here in Louisiana.

    I'm a dentist, and agree completely with what your Dad has written. On the other hand, I don't see this problem as much with my endurance athletes, as I do with the working woman who smokes (dry mouth) and "sips" Diet Coke all day long. Like what your Dad said, the main problem is a dry mouth in an environment full of acid and sugar. And yes, I know that's what happens while training/racing, but I honestly believe that if you are taking care of yourself and your teeth regularly, you won't see a problem. I guarantee these athletes that are having problems, don't have great oral hygiene.

    If this is a big concern for someone, what I would suggest is simply on long runs or during races, if you are taking carbs and drinking sports drinks, you can simply swish with water after you're done, which would help raise the pH of your mouth and wash off the remnants of your aid station pit stop. Also I would strongly suggest having your dentist put you on a prescription strength toothpaste, such as Control Rx, or Prevident. These toothpastes have a very high level of Flouride that would help remineralize those areas under attack.

    Because hey, we can always fix your teeth but you may need that extra Clif Shot to get you a Gold Belt Buckle.

    keep that inspiring attitude Scott,
    Dr. Ryan Walker

  12. Great I'm doubly screwed! I'm a bread baker, which is great for carbs. but awful for teeth. All of the flour creates a very acidic environment in the mouth along with constantly 'tasting' sugary cookies. I have had to start brushing my teeth three-four times a day using a fluoride paste and rinsing twice with fluoride and twice with antiseptic, also flossing.
    It's lot's of work but my mouth has never been happier. Looks like now I have to bring a flask of rinse on my long runs!

    Thanks for the great post.

  13. My dentist commented about this very thing saying that I shouldn't be drinking gatorade and if I did i had to rinse my mouth out with water right after.

  14. I went to the dentist this last week. It sucked!!

  15. Thank you all for your interest and comments. Peter was correct in determining that it WAS a non-cola beverage I was consuming after the Eugene Marathon. Here is Oregon we put some stock in the post-race recussitative potential of "microbrews".
    I'd beg to differ with Paul who thinks that water and electrolytes alone are enough. Our own liver struggles to maintain blood sugar levels after the first hour or so of exercise and we will perform better if we help it along with calorie containing liquids with an osmolality that makes them easily absorbed.
    Red Bull is a great example of a sports drink that's tough on teeth. I'll have to do some research on Nunn, Vitamin Water and Heed...then get back to you.
    Happy trails!

  16. Natural sugars rot your teeth as much as "artificial" sugars. I prefer sports drinks that have a higher maltodextrin to sugar ratio. But I guess this doesn't address the acid issue. Maybe chewing an antacid can help that, aside from the stress-induced peptic ulcer disease and gastritis some of us get. I was thinking of sticking a tooth brush and small tube of paste in my pocket for my next really long race, so maybe this post will make me actually follow through. Thanks, Larry.

  17. Sport Drinks are good.. but are you aware of the fact that it stains teeth very badly?
    However you can try our any teeth whitening solution I think..
    By the way.. thanks for such a Nice post :)


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