Have you ever wondered if there’s a natural way to lower your high blood pressure, guard against Alzheimer's, lose weight, and feel better? Well as it turns out there is. Michael Greger, M.D. FACLM, founder of NutritionFacts.org, and author of the instant New York Times bestseller “How Not to Die” celebrates evidence-based nutrition to add years to our life and life to our years.

Teeth and Smile

Teeth and Smiles

Today we find out how plant-based diets may help prevent oral disease, such as gum disease. 

This episode features audio from Plant-Based Diets: Oral Health, Best Food for Periodontal Disease and Gingivitis, and Childhood Tea Drinking May Increase Fluorosis Risk. Visit the video pages for all sources and doctor’s notes related to this podcast.


Hello and welcome to the Nutrition Facts podcast, I’m your host Dr. Michael Greger. 

Now, I know I’ve made a name for myself in explaining how not to do certain things – just look at my books – How NOT to Die – and my upcoming book, How NOT to Diet.  But what I want to share with you is actually quite positive: what’s the best way to live a healthy life? Here are some answers.

Today we find out how plant based diets may help prevent oral disease such as gum disease. First up –an overview.

Two studies were recently published on plant-based diets and oral health. What do you think they found? Well, for periodontal disease, affecting the tissues surrounding the teeth, like gingivitis (gum disease), one of the leading causes of tooth loss, plant-based diets should be protective.

After all, inflammation “is now recognized as one of the key underlying causal factors in periodontal disease.” And, we know saturated fats “produce an inflammatory response.” And so, no surprise, this recent study found that “High dietary saturated fat intake was significantly associated with a greater number of periodontal disease events.” Saturated fat, which comes primarily, in the American diet, from basically, dairy, donuts, and chicken.

The same diet that leads to high cholesterol may also contribute to periodontitis, as bad cholesterol levels may be a risk factor for both. People with periodontal disease also suffer from arterial dysfunction. Wait a second: inflammation, high cholesterol, and arterial dysfunction; is it any wonder there may be an “Association Between Chronic Periodontitis and Erectile Dysfunction?” 

By looking in your mouth, your dentist may learn more about you than you realize. We know we can reverse impotence with a plant-based diet—what about periodontal disease? A new study found that “higher intake of high-fiber foods, especially fruits, may at least help slow periodontal disease progression…”

For oral cancer, it’s a no-brainer. According to the latest review in the Journal of the American Dental Association, “Evidence supports a recommendation of a diet rich in fresh fruits and vegetables as part of a whole-foods, plant-based diet.”

In our next story we look at what would happen if you stopped brushing your teeth but ate healthier?

Experimentally, if you have people stop brushing their teeth, plaque starts to build up, and within    a few days the gums start to get inflamed. You can’t see anything yet, but if you take a biopsy at the gum line, you can see the inflammation starting to spread. And within a few weeks overt gingivitis becomes apparent, where your gums can get red, swollen, and bleed easily. And if you don’t do anything about it, you can develop periodontal disease, where the inflammation creeps down into the supporting structures of the tooth—the bone and ligaments—setting you up for tooth loss. Okay, but how did we get along for millions of years without brushing? Yeah, “dental disease is almost universal” these days, but thousands of years before the invention of the toothbrush, there are skulls with perfect teeth. Now, you can say, “Yeah, but that was also thousands of years before the invention of candy bars.” But you don’t know…until you put it to the test.

Okay, yeah, but where are you going to find people to not only stop brushing but also to forego eating processed junk? Security guards. That‘s how you do it. It was one of these survivor-type TV shows where people were forced to live under Stone-Age conditions; so, no toothbrushes, toothpaste, dental floss, toothpicks, or other oral hygiene products for a month. Now, they could use a twig or something, but they were pretty much on their own. But, no candy bars either. They were going for about 4,000 BC; so, lots of whole grains, with supplemental salt, herbs, honey, milk, and meat. And then, they could go out and pick berries, or see what they could catch. So, what happened?

With no oral hygiene, their plaque built-up, but their gums got healthier. This is measuring BOP, bleeding on probing (whether or not your gums bled when poked with a dental tool), a measure of gingivitis. And, in almost every case, they got better. Yeah, lots of plaque buildup, but actually healthier gums. How is that possible? Well, many of the more disease-causing bacteria seemed to have disappeared from their mouths. They suggest this could be from the lack of refined sugars. But, they were eating honey; so, it wasn’t like a sugar-free diet. Ah, but what they were eating were lots of whole grains, and berries rich in antioxidant phytonutrients “with anti-inflammatory properties.” So, maybe it was a combination: sugar-intake restriction combined with the intake of really healthy foods. Thus, all those experimental studies where people stop brushing and their gums inevitably get inflamed “may only be applicable” for people eating lots of processed foods rich in sugar and low in anti-inflammatory whole plant foods.

What about “the role of nutrition in periodontal health?” Gingivitis can lead to periodontitis, “an inflammatory disease of the supporting tissues of the teeth,” which “if untreated,” can lead “to the “progressive loss of the bone” that holds the teeth in place. Now, part of the development of periodontal disease may involve oxidative stress. So, not only do we need to reduce our intake of pro-inflammatory foods like refined carbs and saturated fats, maybe it would help if we sought out foods that are antioxidant-rich.

So, is there an association between dietary vitamin C intake, for example, with periodontitis? Apparently so, with increasing risk of periodontitis associated with lower levels of vitamin C intake. But you don’t know…until you put it to the test to figure out what effect vitamin C depletion and supplementation would have on periodontal health. They basically locked everyone up for three months so they can provide controlled amounts of vitamin C and… “measures of gum inflammation were directly related to their vitamin C status.” On about one orange worth of vitamin C, their gums improve, but then down to 5 mg a day, they got worse. But then on 10 oranges’ worth a day, they got better, then worse again when back down to 5. Pretty convincing, though 5 mg a day is like scurvy level. I mean, we know that your gums start bleeding and your teeth can fall out when you have scurvy, but that doesn’t mean taking extra helps.

And indeed, 1,500 mg of vitamin C a day did not seem to help prevent gingivitis. And even 2,000 a day failed to help periodontitis sufferers. Maybe vitamin C is just too weak of an antioxidant? Okay, what about lycopene, the powerful antioxidant pigment that makes tomatoes red? It worked! But that was from injecting the stuff directly into the gum pocket with a syringe. Does it work if you just eat it? Let’s find out.

“A randomised, placebo-controlled clinical trial” on the “efficacy of lycopene in the treatment of gingivitis.” Two weeks of less than a single tomato-a-day’s worth of lycopene versus placebo for two weeks, both along with the standard dental treatment, which helped—a 10 to 20% reduction in gingivitis in the placebo group, but nearly 30% improvement within just one week in the lycopene group. And this was just like the amount of lycopene found in a teaspoon and a half of tomato paste a day. Totally doable. Okay, so tomatoes may help with gingivitis. What about periodontitis?

Another randomized, double-blind, placebo-controlled trial again treated with the usual dental cleaning plus either that one tomato-a-day’s worth of lycopene or a placebo for two months, and significant improvements in plaque gingivitis and bleeding, though not probe pocket depth and clinical attachment. They conclude that supplementation with lycopene seems to have augmented the healing sequence of inflamed gingival tissues.” Okay, but that was with a whole tomato’s worth a day. How about half-a-tomato’s worth, or just three-quarters of a teaspoon of tomato paste worth of lycopene a day? It didn’t work; no difference, so looks like you have to go the whole tomato.

Finally today –we look at how green tea consumption may help prevent cavities, but excessive consumption among young children may lead to dental fluorosis.  Here’s the story.

If cranberries are so good at keeping bacteria from sticking to the wall of the bladder, what about keeping bacteria from sticking to other places? Well, there’s in vitro research suggesting cranberry phytonutrients may reduce adhesion of H. pylori bacteria to the wall of the stomach, and so maybe should be given, along with antibiotics, to help eradicate this ulcer-causing bacteria.

And hey, what about our teeth? Our dental plaque is bacteria sticking to our teeth—particularly Streptococcus mutans. We’ve known that those with different drinking habits—be they coffee, tea, barley coffee, or wine—have about ten times less of this plaque bacteria. Since those are all beverages from plants, maybe phytonutrients are fighting back at plaque.

If bacteria cause plaque and cavities, why not just swish with some antibiotic solution, either synthetic or natural? Well, there are downsides to just indiscriminately wiping out bacteria, both good and bad. So, maybe if we just stop the bad bugs from sticking to our teeth?

Well, there is some evidence that cranberries might affect the adhesion of bacteria to fake teeth in a petri dish, but nothing yet definitive. Green tea also appears to help prevent cavities, which may be because of its natural fluoride content from the tea plant. I have a video about a woman who developed fluoride toxicity, drinking up to like five dozen cups a day. But, what about just regular consumption?

Well, during the tooth development years, up to about age nine, children exposed to too much fluoride can develop dental fluorosis—a mottled discoloration of the teeth. It’s just a cosmetic issue, and usually just kind of faint white spots, but is the main reason the EPA is reconsidering current tap water fluoridation levels.

Currently, the suggested upper limit in water is 2 parts per million of fluoride, and the mandatory upper limit is 4. Herbal teas were fine; about a hundred-fold under this limit. But, caffeinated teas exceeded the suggested limit, and decaf teas exceeded the mandatory limit.

Remember, though, that’s the limit for tap water. So, tea drinking would only pose much of a risk if kids drank it all day long as their primary beverage. So, in terms of the dental ramifications, kids who primarily drank non-herbal tea as a source of hydration may be at risk for dental fluorosis.

We would love it if you could share with us your stories about reinventing your health through evidence-based nutrition. Go to NutritionFacts.org/testimonials. We may be able to share it on our social media to help inspire others. To see any graphs charts, graphics, images or studies mentioned here, please go to the Nutrition Facts Podcast landing page. There you’ll find all the detailed information you need plus links to all the sources we cite to each of these topics.

NutritionFacts.org is a nonprofit, science-based public service, where you can sign up for free daily updates on the latest in nutrition research via bite-sized videos and articles. Everything on the website is free. There’s no ads, no corporate sponsorship. It’s strictly non-commercial. I’m not selling anything. I just put it up as a public service, as a labor of love, as a tribute to my grandmother – whose own life was saved with evidence-based nutrition. Thanks for listening to Nutrition Facts. I’m your host, Dr. Michael Greger.

8 responses to “Teeth and Smiles

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  1. Does it matter if the food does not come into contact with the gums & teeth for example drinking tomato /fruit juice or smoothie through a straw to avoid the erosion of enamel due to acidity ?
    I guess other sources of saturated fats in a plant based/vegan diet are refined coconut products (milk,cream,yoghurt. ..)

  2. Wondering,

    Probably not…..

    You will lose some of the contact time with amylase in the saliva (https://en.wikipedia.org/wiki/Amylase). However, for examples such as tomato juice the absorption of the lycopene and carotenoids and other highly active chemicals from the fruit takes place in the intestines. https://www.ncbi.nlm.nih.gov/pubmed/18641187

    And yes coconut has a very high saturated fat content. A good take on its use can be found here: https://www.health.harvard.edu/staying-healthy/coconut-oil

    Dr. Alan Kadish moderator for Dr. Greger http://www.Centerofhealth.com

    1. Thanks! I’m not sure why you mentioned amylase as tomatoes are not very starchy (just trying to understand your point of view for including it) Interesting PubMed article :)

  3. Is it possible to get the details of the studies referred to please? I am a new subscriber, still trying to find my way around the site. Many thanks.

    1. yes they are under the videos,you can also read the transcript.Ckick on each video after “This episode features audio from” .The actual studies you can get some access for free and others you have to pay.Also your local university or library can help you access the studies.

  4. Hi, I’m a newbie here and am in a strict vegan diet for just 50 days. I have biochemical recurrent prostate cancer that I want to fight against withou radio or chemotherapy.

    My question is: what happened with the ex-vegans that had serious problems of teeth decay, rotten teeth, etc.? I’ve got scared. What do I have to do to prevent it?

    Thank you. You are doing an amazing job!

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