Healthy gums and bones are needed to hold our teeth in place. However, gum disease (periodontal disease) is a common problem in Canada and around the world, so much so that it is now considered a global epidemic (1,2). The World Health Organization has determined that gingivitis, an early form of periodontal disease, is highly prevalent in adults around the world. Advanced disease affects 10% to 15% of adults worldwide (3).
Periodontal disease is an inflammatory condition of the mouth caused by infection of the supporting tissues of the teeth. In gingivitis inflammation is confined to the gingiva (the tooth bearing border of the gums) and is often reversible with consistent oral care such as tooth brushing and flossing along with regular deeper cleaning by a dental practitioner. Symptoms of gingivitis include bright red or swollen gums, tender gums that bleed when brushed or flossed and receding gums. If the condition progresses to periodontitis, the inflammation extends into deeper tissues and leads to pulling away of the gums from the teeth causing deep “gum pockets”, progressive destruction of gum tissue and loss of the bone that anchors the teeth in the mouth. If periodontitis is untreated the result is lost teeth (4).
The primary cause of periodontal disease is poor oral hygiene which allows dental plaque (a sticky film of glycoproteins, mucin, and bacteria) to form on the teeth. If plaque is allowed to remain attached to the teeth for a couple of days, it mineralizes and forms a hard layer called calculus or tartar that provides a welcoming surface for the inhabitation of harmful microorganisms. Systemic conditions such as diabetes, cardiovascular disease and pregnancy are associated with increased risk of periodontal disease (4). Management of periodontal disease includes better dental hygiene by the patient along with scaling of the teeth by a dental practitioner to remove dental plaque. Severe cases might require tissue grafting to cover exposed tooth roots (4).
What about preventing periodontal disease in the first place? Bacterial infection is the main instigator of the damage caused by the condition, however the overall health of the host determines susceptibility to infection. In other words, can promoting better general health affect the initiation and progression of periodontal disease? Recent scientific investigation suggests that periodontitis is directly associated with reduced micronutrient levels in the body, a state most likely caused by poor diet and other lifestyle factors (5).
Optimizing Your Diet for Oral Health
Periodontal disease is a disease of inflammation and oxidative stress is a key factor in chronic inflammation. Oxidative stress occurs from an imbalance between oxidants (ROSs or Reactive Oxygen Species) and antioxidants in the body. When ROS levels overcome antioxidant levels, tissue damage occurs either through direct injury to cells or through alterations of the expression of genes (5). Reducing systemic body inflammation does have beneficial effects on the health of the mouth.
It is well-known that high levels of refined sugars in the diet contribute to dental cavities and periodontal disease. Bacteria in the mouth ferment sugars and produce acid that eats away at the mineral surface protecting the teeth (6). But simple sugars go further than that and there are other food types too that are associated with deteriorating oral health. Foods high in simple sugars, refined carbohydrates and/or saturated fats are linked to chronic inflammation and the risk of periodontal disease (5). High cholesterol levels and a diet high in saturated fats have independently been associated with more than doubling the risk of periodontal disease (7,8). Studies in animals have shown that diets high in saturated fats and cholesterol increase bone loss in the mouth (9). These investigations and many others suggest that if we cut down on inflammatory foods we can increase oral health.
Decreasing intake of harmful foods is one thing but what about the opposite side of the equation? What if we increase foods with beneficial constituents? After all plant-based foods are nutrient dense, offering high levels of complex carbohydrates, dietary fiber, vitamins, minerals, trace elements, folate, phytochemicals and antioxidants. Can these foods help to prevent periodontal disease and lessen its severity?
Many dietary nutrients are known to be valuable for oral health
Foods high in antioxidants reduce oxidative stress. Vitamins A, C and E are antioxidants that act directly by neutralizing ROSs. Vitamin C is especially good in this role and clinical trials have illustrated its ability to reduce gingival inflammation (4). Lycopene, an antioxidant that is the red pigment in foods such as tomatoes, carrots and watermelons, has been shown to bring about improvements of periodontal health (4).
Higher Vitamin D levels are correlated with less progression of periodontal disease although more studies are required to further understand the extent of this effect (4).
Deficiencies of minerals and trace elements including calcium, iron and zinc are linked to worsening periodontal disease (4).
Nitrate-containing vegetables, already recognized as potent preventers of heart disease, have been studied for their influences on periodontal disease. A randomized, double-blind, placebo-controlled trial found that, after 2 weeks of ingestion of a high-nitrate containing juice produced from lettuce, significant improvements in gum disease were observed in the mouths of the participants (10).
High dietary fiber prevents the spikes in blood sugar that trigger inflammation (5).
Dietary patterns and oral health
In 2014 researchers in Germany recruited twenty women with periodontitis and transitioned their diets towards more whole plant foods. After 12 months the subjects had experienced a significant reduction in gum inflammation and depth of pockets around the teeth; and a decrease by as much as 75% in concentrations of inflammatory compounds between the teeth and the gums (11).
The 2014 results mirrored those of a 2009 study of women with existing periodontal disease. Researchers altered their diets for 12 months to focus on whole plant foods including vegetables, fruits, whole-grains, legumes and dairy products with water as the preferred drink. Meat, fish and egg consumption were limited to one or two portions a week. All participants were told to maintain the same oral hygiene practices as performed before the dietary change. After a year, results showed significant reduction in the depth of the participant’s gum pockets along with less gingival inflammation and lower levels of inflammatory substances in the mouth (12).
A 2013 investigation into the oral health of vegetarians discovered that they displayed significantly less inflammation and periodontal damage than the control group of non-vegetarians (13).
A review from 2011 looked at the role of micronutrients in periodontal disease and recommended daily adequate intakes of natural sources of vitamin C and D; polyphenolic flavonoid and carotenoid antioxidants; omega-3 fatty acids; and calcium to prevent and treat periodontitis (14).
Another study found that the higher the intake of dietary fiber, especially sourced from grains, the lower the incidence of periodontal disease (15).
An interesting on-going study was initiated in the 1980s with 1062 seven-month-old infants who were entered into a randomized, controlled trial investigating saliva and dental health. The parents of half the infants were counselled to decrease saturated fat and cholesterol in their child’s diet; the parents of the remaining children received no intervention advice for the diet of their children. Actual dietary intakes of carbohydrates, protein, saturated fat, calcium, phosphate, and fiber have been regularly recorded over the study period so far. The “children” are now in their 20s and are still being monitored by the researchers. The interesting finding here as that those participants in the healthier low-fat diet group are producing higher volumes of saliva (16). Saliva is crucial for good oral health. It functions to lubricate the mouth, dilute sugars, “wash” food off the teeth and moisten food for easier swallowing; it has antibacterial activity; it neutralizes acid production and controls plaque formation; and it helps with remineralization of enamel and tissue repair (17). In this study the increased flow of saliva was attributed to eating more fiber-rich food which requires more chewing and produces more saliva. In addition, the amount of calcium in the saliva could be directly correlated with better dental health. Researchers summarized results by saying that “in addition to general health benefits, dietary fiber may have benefits on oral health as well” (16).
Supplements have not been found helpful for periodontal disease. This is not surprising. This has been noticed in other situations where improving overall health was the goal. Natural whole food sources are made up of complex intertwinings of nutrients within a matrix such that the benefits they deliver are over and above a simple addition of their content of individual micronutrients. Additionally, overloading with a single nutrient can destabilize the delicate balances between nutrients and interfere with micronutrient interactions (5,14).
Food choices for promoting oral health
Foods to emphasize
When it comes right down to it, it’s easy to choose foods that promote oral health. Simply eat plants!
Antioxidants are found only in plants.
Plants high in antioxidants include (18);
Green leafy vegetables – spinach, Brussels sprouts, cabbage, kale, arugula
Other vegetables -artichokes, bell peppers, asparagus, beets, broccoli, red cabbage, tomatoes, sweet potatoes, carrots, yellow and orange squash
Berries – blueberries, blackberries, raspberries, strawberries, cranberries
Other fruits – apples (with peel), grapes, citrus fruits, peaches, nectarines, apricots, cherries, plums, prunes, banana, kiwi, dates, mango and guava
Legumes – red lentils, kidney beans, black beans, edamame
Nuts – Walnuts, pistachios, pecans, hazelnuts and almonds
Seeds – sunflower, sesame, ground flaxseed
Other – tea, coffee, dark chocolate
Fiber is found only in plants.
Natural nitrates are also only obtained from plants. The highest nitrate-containing plants are arugula (rocket), spinach, lettuce, radish, beetroot, Chinese cabbage, celery and cilantro. Moderate sources include turnip, cabbage, green beans, leek, spring onion, cucumber, carrot, potato, garlic, green pepper and sweet pepper (19,20).
The richest sources of omega-3 fatty acids in plants are seeds (chia seeds, flaxseeds, hemp seeds) and walnuts, sources which provide these fatty acids in a healthy ratio of omega-3 to omega-6 fatty acids (21). This is important because the same enzyme is used when either of these fatty acids are converted to longer-chain fatty acids and, if the level of omega-6s is too high, fewer omega-3s will undergo the conversion. The standard western diet is very high in the omega-6 fatty acids because they are present in vegetable oils (for example, safflower, sunflower, and corn oils) as well in processed foods (22).
Plant-based foods are also excellent sources of vitamins, minerals and trace elements.
The evidence is plentiful that a plant-based diet is a healthy one. Comparisons of different diets consistently find that a completely plant-based vegan diet based on whole foods provides all the nutrients we as human beings need to thrive. Compared to vegetarian, semi-vegetarian, pesco-vegetarian and omnivorous diets, vegan diets consisting of whole plant foods come out on top, supplying all the macronutrients (carbohydrate, fat and protein) and micronutrients (vitamins, minerals, trace elements and antioxidants) that are required for good overall health (23,24). The Academy of Nutrition and Dietetics states that “a well-planned plant-based diet can easily provide all the nutrients necessary to thrive” and “may provide health benefits for the prevention and treatment of certain diseases”. They further assert that plant-based diets “are appropriate for all stages of the life cycle, including pregnancy, lactation, infancy, childhood, adolescence, older adulthood, and for athletes.” (25)
Foods to reduce
Reduce intake of saturated fats.
Reduce intake of processed vegetable oils of all kinds, especially those high in omega-6 fatty acids such as safflower oil, sunflower oil and corn oil.
Reduce refined carbohydrates and processed foods.
Reduce intake of simple sugars. If you do eat a sugary food try to brush your teeth soon afterwards. If brushing is not possible, rinse your mouth with green tea or chew some gum sweetened with xylitol (a sugar alcohol). Both xylitol and green tea act as anti-bacterials in the mouth (26,6).
Other Lifestyle factors that promote oral health
Diet is not the only lifestyle choice that can influence the health of your teeth and gums.
Smoking is associated with a higher risk of periodontitis. Tobacco use is an independent risk factor for periodontal disease, with an enormous influence on the development, progress and severity of the disease. Additionally, smoking can lower chances of successful treatment (27).
Physical activity – The Health Professionals Follow-Up Study noted a significantly lower risk of periodontitis with higher levels of sustained physical activity. This effect was independent of that from known risk factors (28).
Date from the NHANES III study agreed, coming to the conclusion that adults with higher levels of physical activity had significantly lower risks of periodontitis. This association was strongest in non-smokers, likely because the harmful effects of smoking outweigh any benefit derived from physical activity (29).
Obesity – A recent meta-analysis revealed a significant association between periodontitis and obesity (29).
Though we may not think about our teeth very often, except perhaps when our next dental appointment looms on the horizon, we all want to ensure that our “pearly whites” remain healthy into our old age. Lost teeth can affect overall nutrition. Not only can tooth loss limit food choices but chewing also becomes less efficient so that the food is not properly prepared for effective digestion in the stomach and beyond. And of course no one wants conspicuous gaps in their mouth or huge costs for tooth replacements.
The European Workshop on Periodontology now advises dental practitioners to counsel their periodontal patients on increasing fiber, fruit, vegetables and omega-3 fats in their diets, saying that there is now overwhelming evidence of the importance of diet for oral health and a wide range of other chronic diseases (5). The fact that the same diet that reduces the risk of many of the diseases of aging (cancer, cardiovascular disease, type-2 diabetes) also diminishes risk of periodontal disease is just one more reason to boost the intake of plants in our diets.
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