Nutrition for oral and dental health

Diet and nutrition play key roles in tooth development, the integrity of the gingiva (gums) and mucosa, bone strength, and the prevention and management of diseases of the oral cavity. Diet has a local effect on tooth integrity; the type, form, and frequency of foods and beverages consumed have a direct effect on the oral pH and microbial activity, which may promote dental decay. Nutrition systemically affects the development, maintenance, and repair of teeth and oral tissues.

It is important to differentiate between cariogenic, cariostatic, and anti-cariogenic foods. 

• Cariogenic foods are those that contain fermentable carbohydrates, which, when in contact with microorganisms in the mouth, can cause a drop in salivary pH to 5.5 or less and stimulate the caries process.

Fermentable carbohydrates are found in three of the five MyPlate food groups: (1) grains, (2) fruits, and (3) dairy. Although some vegetables may contain fermentable carbohydrates, little has been reported about the cariogenicity, or caries-promoting properties, of vegetables. Examples of grains and starches that are cariogenic by nature of their fermentable carbohydrate composition include crackers, chips, pretzels, hot and cold cereals, and breads. All fruits (fresh, dried, and canned) and fruit juices may be cariogenic. Fruits with high water content, such as melons, have a lower cariogenicity than others, such as bananas and dried fruits.

Fruit drinks, sodas, ice teas, and other sugar-sweetened beverages; desserts; cookies; candies; and cake products may be cariogenic.

Dairy products sweetened with fructose, sucrose, or other sugars can also be cariogenic because of the added sugars; however, dairy products are rich in calcium, and their alkaline nature may have a positive influence, reducing the cariogenic potential of the food. Like other sugars (glucose, fructose, maltose, and lactose), sucrose stimulates bacterial activity.

The causal relationship between sucrose and dental caries has been established. All dietary forms of sugar, including honey, molasses, brown sugar, agave, and corn syrup solids, have cariogenic potential and can be used by bacteria to produce acids that erode enamel.

• Cariostatic foods do not contribute to decay, are not metabolized by microorganisms, and do not cause a drop in salivary pH to 5.5 or less within 30 minutes. Examples of cariostatic foods are protein foods such as eggs, fish, meat, and poultry; most vegetables; fats; and sugarless gums.

According to the American Dental Association (ADA), sugarless gum may help to reduce decay potential because of its ability to increase saliva flow and because it uses noncarbohydrate sweeteners.

Anticariogenic foods are those that, when eaten before an acidogenic food, prevent plaque from recognizing the acidogenic food. Examples are aged cheddar, Monterey Jack, and Swiss because of the casein, calcium, and phosphate in the cheese. The five-carbon sugar alcohol, xylitol, is considered anti-cariogenic because bacteria cannot metabolize five-carbon sugars in the same way as six-carbon sugars such as glucose, sucrose, and fructose. It is not broken down by salivary amylase and is not subject to bacterial degradation. Salivary stimulation leads to the increased buffering activity of the saliva and subsequently increased clearance of fermentable carbohydrates from tooth surfaces. Another anti-cariogenic mechanism of xylitol gum is that it replaces fermentable carbohydrates in the diet. S. mutans cannot metabolize xylitol and is inhibited by it. The antimicrobial activity against S. mutans and the effect of gum chewing on salivary stimulation are protective. Consumers should be advised to look for chewing gum in which xylitol is listed as the first ingredient.