March 2015 Issue

Practice Matters: Diabetes and Oral Health — It's a Two-Way Street
By Densie Webb, PhD, RD
Today's Dietitian
Vol. 17 No. 3 P. 58

Most clinicians are aware that patients with type 1 or type 2 diabetes are at increased risk of poor oral health: dental caries, periodontal disease (gingivitis and periodontitis), bone loss, and, ultimately, tooth loss. In fact, the risk of periodontitis for people with diabetes is three times that of patients without diabetes. Diabetes increases not only the prevalence and severity of periodontitis, but the rate at which the condition progresses. It may be less well known, however, that poor oral health among those with diabetes increases the risk of poor glycemic control and the development of diabetes complications.1

Diabetes and periodontitis have several disturbing characteristics in common. They're both prevalent, chronic diseases that often go undiagnosed; they affect similar segments of the population; and successful outcomes depend heavily on intensive intervention, lifestyle modifications, and lifelong maintenance. That's where dietitians come in.

Periodontal Disease Defined
Before nutrition professionals become involved with the oral health issues of their clients and patients, it's critical to know exactly what periodontal disease is. Periodontal disease and dental caries are the most prevalent chronic infectious oral conditions.2 Periodontal disease can range from mild, such as gingivitis (inflammation of the gums), to chronic, severe periodontitis, in which the bone and collagen that support teeth are destroyed, resulting in tooth loss.2 While gingivitis is treatable, loss of bone and collagen that support teeth is irreversible. According to Evanthia Lalla, DDS, MS, a professor of dental medicine at Columbia University, "Gingivitis is to periodontitis as prediabetes is to diabetes. Gingivitis doesn't always lead to periodontitis, but it increases the risk." Periodontal disease, whether mild or severe, rarely causes pain; that's why prevention is so important, as well as early diagnosis and treatment.

According to the Centers for Disease Control and Prevention, 47% of adults aged 30 and older have some form of periodontal disease. That number increases with age; 70% of adults aged 65 and older have periodontal disease. It's more common among men than women (56% vs 38%, respectively). Based on information released in 2012, for people with diabetes, periodontal destruction can begin as young as age 6. Individuals with less than a high school education or income below the poverty level have a high prevalence of periodontal disease (67% vs 65%, respectively), even higher than current smokers (64%).

Bidirectional Link
The link between diabetes and periodontal disease was first reported in medical literature in the 1960s. However, it hasn't been covered as extensively as the effects of diabetes on other systems in the body.1

Diabetes Affects Oral Health
Diabetes can result from excessive consumption of advanced glycation end products, compounds that stem from cooking foods at high temperatures, and that are also part of normal metabolism. Glycation of these compounds, in the form of proteins or lipids, results from exposure to elevated blood sugar and can contribute to the development of atherosclerosis,3 increase oxidative stress, activate proinflammatory pathways, and hinder tissue repair, all of which raise the risk of periodontal disease. An aggravated immune response, or hyperinflammatory response, in people with diabetes to the bacteria associated with periodontitis is thought to explain, in part, the link between diabetes and poor oral health.1 Diabetes also decreases the amount of collagen in periodontal tissues, both by reducing collagen synthesis and increasing its degradation.1

Oral Health Affects Diabetes
Research suggests that previously healthy patients with severe periodontitis are at increased risk of developing diabetes. In addition, periodontitis can have significant adverse effects on diabetes outcomes. For example, severe periodontitis in people with diabetes has been shown to increase the risk of poor glycemic control, which creates a higher prevalence of renal disease, cardiovascular complications, and associated mortality. It's also associated with type 2 diabetes development in previously healthy individuals. Type 2 diabetes generally is preceded by systemic inflammation, which can lead to impaired functioning of pancreatic beta cells, cell death, and insulin resistance.4 Periodontal bacteria make their way into the circulation, possibly increasing systemic inflammation and contributing to insulin resistance.

Other Contributing Risk Factors
According to Riva Touger-Decker, PhD, RD, CDN, FADA, from Rutgers School of Health Related Professions, dry mouth (xerostomia) can be a risk factor for periodontal disease, and there are more than 600 prescription medications that can cause dry mouth, some of which may be prescribed to people with diabetes.

Eating disorders among diabetes patients, especially bulimia (sometimes referred to as diabulimia), present another risk factor.5 The acidic gastrointestinal contents from purging regularly expose the teeth and gums to acid, damaging them both. Unexplained elevations in A1c values can be indicative of an eating disorder in people with diabetes. In addition, individuals diagnosed with anorexia are at increased risk of dry mouth due to antidepressants, diuretics, or nutrient deficiencies.2

It also has been suggested that obesity may create a triangular relationship with type 2 diabetes and periodontal disease.6 Obesity may be an indirect risk factor for periodontal disease because of its effect on glycemic control and a direct risk factor because it triggers the release of proinflammatory agents through adipose tissue, which can affect periodontal tissue.

The Dietitian's Role
While prevention of both type 2 diabetes and periodontal disease is key, meta-analyses have concluded that periodontal therapy in individuals with diabetes can result in a modest improvement of glycemic control.1 It's now within the scope of practice for RDs to complete a nutrition-focused physical assessment of patients' oral health.2 Part of that is asking patients about the medications they're taking.

The May 2013 issue of the Journal of the Academy of Nutrition and Dietetics offered guidelines for dietitians, registered dietetic technicians, and oral health care professionals in clinical, community, and research settings to identify and treat periodontal disease.2

Among the guidelines are recommendations for RDs and oral health professionals to work together as part of an interdisciplinary health care team to address associations between oral and general health. The European Federation of Periodontology and the American Academy of Periodontology issued a joint consensus report in 2013, stating that lifestyle modifications, including diet and exercise, could be better achieved in collaboration with "appropriate specialists," which would include RDs.

Identification of prediabetes, type 2 diabetes, and periodontal disease shouldn't be the responsibility of a single group of health care providers. RDs should act as part of the health care team and participate in early diagnosis so that treatment can be initiated.

Lalla recommends dietitians discuss oral health with patients and its importance for overall health and well-being; advise diabetes patients to see a dentist on a regular basis; screen for oral and periodontal changes in the color, texture, and moisture of the gums, the hard palate, and the floor of the mouth beneath the tongue; check for bleeding gums and ulcerations; and communicate with dental professionals, offering advice and information about mutual patients.

When referring someone at risk of, or diagnosed with, diabetes to a dental health professional, a dietitian should assess and/or physically examine the client regarding the following:1,4,7,8

• smoking;
• poor oral hygiene;
• stress;
• heredity;
• crooked teeth;
• underlying immune deficiencies, such as AIDS;
• fillings that have become defective;
• taking medications that cause dry mouth;
• bridges that no longer fit properly;
• female hormonal changes, such as pregnancy or the use of oral contraceptives; and
• bulimia.

A more extensive list can be found at
An estimated 86 million adults in the United States have prediabetes. Almost 90% of them are undiagnosed. As the prevalence of diabetes and obesity increases and the understanding of their relationship with periodontal disease grows, there's a need for health care professionals, including dietitians, to comanage patients.1 Preventing type 2 diabetes through weight loss, physical activity, and diet therapy can reduce the risk of developing serious periodontal disease, and dietitians can play an important role in diagnosis and referral to a dental health care professional.

— Densie Webb, PhD, RD, is a freelance writer, editor, and industry consultant based in Austin, Texas.


Warning Signs of Periodontal Disease

• Bad breath or bad taste that won't go away

• Red or swollen gums

• Tender or bleeding gums

• Painful chewing

• Loose teeth

• Sensitive teeth

• Gums that have pulled away from your teeth

• Any change in the way the teeth fit together when biting down

• Any change in the fit of partial dentures

— DW


1. Lalla E, Papapanou PN. Diabetes mellitus and periodontitis: a tale of two common interrelated diseases. Nat Rev Endocrinol. 2011;7(12):738-748.

2. Touger-Decker R, Mobley C, Academy of Nutrition and Dietetics. Position of the Academy of Nutrition and Dietetics: oral health and nutrition. J Acad Nutr Diet. 2013;113(5):693-701.

3. Goldin A, Beckman JA, Schmidt AM, Creager MA. Advanced glycation end products: sparking the development of diabetic vascular injury. Circulation. 2006;114(6):597-605.

4. Chapple IL, Genco R, Working group 2 of joint EFP/AAP workshop. Diabetes and periodontal diseases: consensus report of the Joint EFP/AAP Workshop on Periodontitis and Systemic Diseases. J Clin Periodontol. 2013;40 Suppl 14:S106-S112.

5. Eating disorders/"diabulimia" in type 1 diabetes. Joslin Diabetes Center website.

6. Levine RS. Obesity, diabetes and periodontitis—a triangular relationship? Br Dent J. 2013;215(1):35-39.

7. Stepwise approach to the conduct of the nutrition focused physical exam: head, neck and oral screen. Rutgers School of Health Related Professions website.

8. What is periodontal disease? Centers for Disease Control and Prevention website. July 10, 2013.