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The impact of nutrition and diet on oral health

Think brushing and flossing are enough to maintain oral health? Think again.

October 22, 2020

The impact of nutrition and diet on oral health

Think brushing and flossing are enough to maintain oral health? Think again. Studies point to a bidirectional relationship between oral health and diet and nutrition. That is, diet and nutrition affect the health of the tissues in the mouth, and the health of the mouth affects nutrients consumed.

Mouth-body connection

The mouth-body connection is a strong indicator of overall bodily health. Without proper oral hygiene, bacteria in the mouth can reach levels that could lead to oral infections, like tooth decay and gum disease (periodontitis). Poor oral health is linked to heart disease, diabetes, cancer, and Alzheimer’s disease, and it can influence a person’s functional ability to eat.

  • Heart disease Poor oral health as a possible cause of heart disease has been studied for years. While the connection is not fully understood, research suggests heart disease, clogged arteries and stroke might be linked to the inflammation and infections that oral bacteria can cause.
  • Diabetes The link between diabetes and oral health problems is high blood sugar. When blood sugar is poorly controlled, oral health problems are more likely to develop. Research shows people with diabetes are at increased risk of dry mouth and gum disease, which can lead to chewing difficulties and even tooth loss.
  • Cancer Studies show poor oral health may increase cancer risk. A recent study led by researchers from Harvard T.H. Chan School of Public Health showed people with a history of gum disease have a greater risk of stomach cancer and throat cancer compared to people without gum disease. Having lost two or more teeth also increased risk. Another new study, published in Cancer Prevention Research, showed gum disease may heighten the risk for colorectal cancer.
  • Alzheimer’s disease In a recent study published in Neurology, severe gingivitis with tooth loss was associated with an increased risk of Alzheimer’s disease and other forms of dementia.

A number of factors can put people at risk for poor oral and overall health

  • Pregnancy
    Pregnant women may be more prone to gum disease and cavities, says the Centers for Disease Control and Prevention (CDC). Changing hormone levels in pregnancy directly affects gum problems, and indirectly, tooth decay. Poor oral health during pregnancy can lead to poor health outcomes for mother and baby — including, but not limited to, premature delivery, low-birth-weight baby, pre-eclampsia, gingivitis, loose teeth, and dental erosions.

In addition, women who have a lot of cavity-causing bacteria during pregnancy and after delivery could transmit the bacteria from their mouth to that of their baby. Early contact with these bacteria and to other sugars, such as from frequent snacking or taking a bottle to bed, can lead to early childhood cavities and the need for extensive dental care at a young age.

  • Medications
    Literally, hundreds of medications (prescription, herbal, vitamins, and over-the-counter) can cause dry mouth, which not only increases risk for tooth decay, but can also create problems with eating, chewing and swallowing. This can result in a poor nutritional state that can negatively impact oral health.
  • Restrictive diets/allergies
    People with food allergies and those on restrictive diets (like gluten-free, vegetarian, and vegan) have a higher chance of experiencing vitamin and protein deficiencies, putting them at higher risk for tooth decay and gum disease. Any time there is an elimination or restriction of specific food groups, nutritional deficiencies are possible.
  • Eating disorders
    Eating disorders, such as anorexia, bulimia, and binge eating, can severely impact oral health, causing lingering or even permanent damage to the teeth and mouth. By depriving the body of essential nutrients, gums and other soft tissue inside the mouth may bleed easily. The glands that produce saliva may swell, and individuals may experience chronic dry mouth. Stomach acid from vomiting can damage tooth enamel, changing the color, shape, and length of teeth.

Quick tips for mouth-to-body health

  • Drink plenty of water, and always keep your mouth moist. Saliva protects hard and soft oral tissues. If you have a dry mouth, stimulate saliva with sugarless candy or gum.
  • Choose foods from the five major food groups: fruits, vegetables, breads and cereals, milk and dairy products, and meat, chicken, fish, or beans. Avoid fad diets that limit or eliminate entire food groups, which can result in vitamin or mineral deficiencies.
  • Snack smartly. Avoid soft, sweet, sticky foods (like candy and dried fruits), which stick to teeth and can cause tooth decay. Choose nuts, raw vegetables, plain yogurt, cheese, and sugarless gum or candy.
  • Brush twice daily with fluoride toothpaste that has the American Dental Association Seal of Acceptance. Floss daily and visit your dentist regularly. Routine dental care can prevent problems from occurring in the first place or catch issues early, while still treatable.



Azofeifa A, Yeung LF, Alverson CJ, Beltrán-Aguilar E. Dental caries and periodontal disease among U.S. pregnant women and nonpregnant women of reproductive age, National Health and Nutrition Examination Survey, 1999–2004. Journal of Public Health Dentistry, 2016;76: 320-329. doi:10.1111/jphd.12159.