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.

What is the effect of nutrition on periodontal disease? “Periodontal disease is a bacterial infection that results in inflammatory destruction of the connective tissue and bone that support the teeth,” and is therefore “one of the leading causes of” our teeth falling out. Like most infections, though, how our body responds may play a critical role. Yes, “the presence of bacteria is the primary [cause, but] a susceptible host is also necessary for disease initiation.”

The standard explanation of periodontal disease is the plaque theory: the buildup of plaque leads to gingivitis—gum inflammation—which leads to the periodontitis, inflammation lower down beneath the gums. But in some forms of periodontal disease, plaque doesn’t appear to play a critical role. Therefore, in the last few years, there has been more interest in the importance of systemic health, our body’s response. “In this respect, nutrition may be of great importance, since it has been implicated in a number of [other] inflammatory diseases”—all of which carry elevated periodontal disease risk.

Traditionally, when we think of the effects of nutrition on dental diseases, we’re only thinking about cavities. However, there’s been less research on the role of diet in periodontal disease. Well, but if it’s about inflammation, one would expect “saturated fat-rich diets” to make things worse—increasing oxidative stress as well inflammation. So, we may want to cut down on saturated fat. But let’s not just speculate. I mean, is there an association between cholesterol levels and periodontitis? If not, it would be hard to implicate saturated fat. But no, there does appear to be a link. Those with high cholesterol do appear to have up to double the risk.

What about periodontal conditions in vegetarians? A hundred vegetarians versus non-vegetarians were studied, and those eating vegetarian did have “better periodontal conditions (less inflammation signs, less periodontal damage, and better dental home care).” However, it should be considered that vegetarians may not just be avoiding meat, but are healthier in other ways, like better dental home care.

But do people who eat more saturated fat get more periodontitis? Yes, about double the risk at the highest levels of intake. And this study was in Japan, where they eat less than half the meat and dairy compared to the U.S. The only way to know for sure, though, is to do an interventional trial, where you change people’s diets and see what happens. In other words, you have to put it to the test. And, bone loss was indeed magnified by a diet high in saturated fat and cholesterol. But if you’re thinking hmm…that’s a weird-looking jaw, that’s because it was a study done on rats.

This is what I was looking for, though the title kind of ruins the suspense. “A high-fiber, low-fat diet improves periodontal disease markers” in terms of probing depth, clinical attachment loss, and bleeding on probing—all the standard measures. And, of course, eating a healthier diet, body weight, blood sugar control, and systemic inflammation improved as well. Ah, but that complicates things. Maybe their mouths got better just because they lost so much weight. You can improve periodontal disease with just bariatric surgery, like stomach stapling. Well, after eight weeks on the diet, they went back on their regular diet, and so gained most of that weight back. But the periodontal disease improvements persisted, suggesting that it was more than just the weight loss that lead to the improvements. They’re thinking maybe the high-fiber diet altered their good gut flora, or maybe their oral flora? What exactly was going on?

Well, German researchers took 20 women with mild-to-moderate chronic periodontitis, and for a year, tried to transition their diets towards more wholesome nutrition—meaning more plant foods, more whole foods, more fresh foods, trying to center their diets around vegetables, and fruit, whole grains, potatoes, and legumes—beans, split peas, chickpeas and lentils. And….after 12 months, the patients “showed a significant reduction of probing pocket depth, gingival inflammation and, [measured for the first time,] decreased concentrations of inflammatory” chemicals inside the crevice between the tooth and gums, which are thought responsible for “the tissue destruction in periodontal disease”—a decrease by as much as 75 percent. And, all the while, their “oral hygiene status did not change,” suggesting it was the diet that did it. But what was missing here? A control group. But there’s never been any randomized, double-blind, placebo-controlled trials of diet for periodontal disease …until now, which we’ll cover next.

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