Transcript: Plant-Based Diets: Dental Health
Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
The foods found most protective against oral cancer include raw and green/leafy vegetables, tomatoes, citrus, and carrots. Citrus fruits are acidic, though. Fine; less oral cancer. But, what about the health of the teeth themselves? Might eating lots of sour fruit eat away at our enamel?
Well, early case reports that raised red flags involved things like “sucking [on] lemon wedges”—not, evidently, a good thing for your teeth. Or, “rampant” cavities, as a result of the “bizarre habit of sucking bananas.” Turns out you’re not supposed to give your preschooler a banana to suck on day and night as a pacifier. Juicing 18 oranges a day for a decade or two can also take quite a toll.
The conventional wisdom that fruit juice may be bad for your teeth, but not whole fruit, was challenged recently. The ability of fruits and their juices to erode enamel appears to be comparable, whether you’re eating grapes or grape juice, carrots or carrot juice, oranges, apples, tomatoes, or raisins.
Now, fruits and juices weren’t as bad as soda. Diet Coke takes the title for softening teeth the quickest. But, it was a surprise that fruits and their juices had comparable effects—a result no doubt celebrated by the study’s funders, the Sugar Bureau, as well as the Biscuit, Cake, Chocolate and Confectionery Association.
The spin the Dental Association put on it is interesting: If “eating fruits and vegetables as ‘whole’ foodstuffs may cause similar demineralisation in enamel to when they are consumed as a juice,” then, hey, maybe fruit juice is not so bad at all.
Of course, the glass-half-empty interpretation is that, wait a second, fruit is as bad as juice? Maybe, fruit is worse than we thought for our enamel. And, indeed, the latest research studying whether or not the consumption of fruit is cavity-causing found that “the frequency of fruit consumption was associated with higher odds” of cavities—though they acknowledge that “the role of fruit sugars in initiating dental [cavities] in humans has [certainly long] been a subject of debate.” But, is this going to be a problem for those eating like this, as opposed to this?
“Among vegetarians, significantly more frequent consumption of sour products (predominantly raw vegetables and fruit and tomatoes) was observed.” Though “[t]he level of oral hygiene [was] similar in both groups,” those eating vegetarian did have more erosive lesions on their teeth—but did not find enough to be statistically significant, unlike the other study. No differences in plaque, gingivitis, cavities, or tooth loss, but they did find a “greater incidence of demineralization and white spots in [the] vegan subjects compared to [the] omnivorous ones,” which is a marker of greater acid erosion.
So, what should people do? There are a number of “foods and drinks that have the potential to cause dental erosion”—both unhealthy foods, like soda and sour candy, as well as healthy foods, such as fresh fruit, and some herbal teas. In the biggest study to date, consuming citrus fruits more than twice a day was associated with 37 times greater odds of dental erosion, compared to those who consumed citrus fruits less often. It also appears risky to consume apple cider vinegar or sports drinks once a week or more often, or soft drinks daily. These habits resulted in the odds of erosion being ten, four, and four times greater, respectively, than when the habit did not exist.
So, should we avoid eating citrus? No. Even the study that found more cavities in kids eating more fruit concluded that even though “the consumption of fruit might not be considered completely safe to eat in relation to [cavities], we are not in a position to suggest that fruit consumption should be curtailed as a [cavity]-preventive measure. At this stage, of greater importance is the preventive advice that children should brush their teeth twice [a day with] fluoride toothpaste.”
In fact, that study that looked at the erosive potential of fruit was done on folks without using fluoride toothpaste. Just don’t brush right after you eat the fruit, though. You have to wait at least 30 minutes. See, people have this “misconception that brushing immediately after consuming acidic food and beverage[s] would prevent the damaging effects of dental erosion,” when “[I]n fact, the tooth surface when softened by acids from food and beverage is more vulnerable to damage by tooth brushing.”
They did this study where they had some folks swish some acidic solution—in this case diet Sprite, and then brush immediately after, or 10 minutes after, 20 minutes after, 30, or a full hour after. As you can see, if you drink soda without brushing at all, you may lose some of your teeth. But, you can double or triple that damage if you then start brushing your teeth when they’re in that acidified, softened state.
They say we should wait at least 30 minutes; probably a whole hour, to be safe. Instead of brushing, after eating anything sour, we should “rinse [our mouth] with water to help neutralize the acids.”
Is there any evidence to support this? No, unfortunately. “Due to the limited number of clinical studies performed to investigate the association between diet and dental erosion, prevention and treatment (from a dietary perspective) are based [really] on common sense, rather than [an] evidence-based approach[es].” In fact, there’s not a single study concerned with dentist advice for “dietary change aimed at preventing tooth erosion.” But, rinsing with water after eating or drinking anything acidic is the best advice we have so far.
Please consider volunteering to help out on the site.