The Fattening of America and Its Effect on Oral Health

The growing incidence of obesity is creating a health care crisis in the United States. Approximately 59 million Americans—more than 30% of the US population—are classified as obese.¹ Hypertension, high cholesterol, type 2 diabetes, heart disease, stroke, and some cancers are just some of the negative health effects related to obesity. Not surprisingly, obesity also appears to affect oral health as well.

Early onset obesity may affect periodontal health through alterations in lipid metabolism, poor diet, and high stress levels. A link between periodontitis and obesity has been noted in scientific literature like the New England Journal of Medicine and some studies have demonstrated that obesity contributes to the severity of periodontitis.^2-4

If historical obesity trends continue through 2020 without other changes in behavior or medical technology, the population may be at risk for higher incidence of chronic illness than it is today.⁵ Weight reduction should be an urgent public health priority. The prevalence of obesity and its strong association with chronic health conditions ixllustrate that weight reduction could mitigate the effects of obesity on the incidence of certain diseases and could significantly improve quality of life. Dental hygienists, as health care providers, are poised to play a role in treating this American health epidemic.

Insulin Resistance

Obesity is an excessively high amount of body fat or adipose tissue in relation to lean body mass. The adipocytes in obese people produce large quantities of biologically active molecules such as leptin, an important molecule regulating energy outflow and body weight. Adipocyte-derived active molecules, named adipocytokines, are contender molecules that account for the close association between obesity and other multiple risk factor syndromes, such as type 2 diabetes. The pro-inflammatory cytokine tumor necrosis factor alpha (TNF-a) is produced by adipocytes. Its blood concentration is higher in obese people and drops with weight loss. TNF-a interferes with the action of insulin by blocking the body’s cell-surface insulin receptors, possibly leading to insulin resistance. In inflammatory diseases, such as periodontitis, the chronic release of TNF-a into the systemic circulation is a likely mechanism contributing to the state of insulin resistance. TNF-a produced due to periodontal inflammation may be another factor that influences insulin sensitivity in the obese and type 2 diabetics. This relationship is a possible mechanism that explains the reciprocal relationship between type 2 diabetes and periodontal diseases.^2,6

TNF-a induced by periodontal pathogens and circulating TNF-a produced by adipose tissue in obese people may contribute to more severe periodontal diseases by activating osteoclasts and mediating alveolar bone resorption. Successful periodontal treatment, including removal of microbial biofilm, may decrease the levels of circulating TNF-a in patients with periodontal diseases and improve metabolic control in diabetes through a reduction of insulin resistance. TNF-a levels are also decreased with successful weight loss.⁷

The New Guidelines

Interventions aimed at preventing and reducing obesity through the promotion of healthful eating and physical activity may be effective in improving periodontal health.⁶ Poor dietary patterns and physical inactivity, which results in an energy imbalance, are the most significant factors contributing to the increase in obesity in the United States. The 2005 Dietary Guidelines for Americans provide the latest science-based recommendations for promoting health and reducing risk of chronic diseases through diet and physical activity. The guidelines are based on the recommendations of the Dietary Guidelines Advisory Committee, which is composed of scientific experts who reviewed and analyzed the latest nutritional information. For the first time, the committee used a more rigorous, evidence-based approach to reviewing the most current dietary and nutritional information.

The new Dietary Guidelines are oriented toward policy makers, nutrition educators, nutritionists, and health care providers rather than the general public. The Dietary Guidelines provide a framework to promote healthier lifestyles and to aid the public in reducing the risk of obesity and chronic diseases by providing information and advice on choosing nutrient-dense foods, maintaining a healthy weight, achieving adequate exercise, and keeping foods safe to eat.⁸

The Dietary Guidelines are a foundation of the United States Department of Agriculture (USDA) Food Guidance System. MyPyramid⁹ replaces the Food Guide Pyramid that was introduced in 1992. MyPyramid provides web-based interactive and print materials for consumers and also materials designed for health care professionals.

Taking Action

ADHA advocates and supports “the development of eating habits consistent with the Dietary Guidelines for Americans.”¹⁰ The dental hygienist is a resource for nutrition information, is competent to provide basic dietary guidance, and can recognize when a patient has nutritional needs that require a referral to a physician or registered dietitian.¹¹ Many dental hygienists today are hesitant to provide dietary guidance to their patients, mainly due to feeling unprepared in the content of nutrition information and how to apply it in clinical practice.¹² CDHA provides web-based nutrition resources and tools for dental hygienists (http://www.cdha.org/public_health/eating.htm) to perform diet screening, offer basic nutrition education and guidance, and to assess diet adequacy. Consumers are also welcome to use the website.

Click to View Table [ PDF Format | JPG Format ]

Prevention and management of obesity may be effective in improving periodontal health. Obesity is a form of malnutrition—consuming more calories than needed without meeting recommended intakes for certain nutrients. General malnourishment impairs normal growth, development, and maintenance of the body’s tissues and organs. It impairs immune responses and wound healing, and is relevant to periodontal health.¹³ The Dietary Guidelines provide the most recent nutrient intake recommendations needed for growth and health. The USDA Food Guide⁸ is an example of an eating pattern that integrates the new Dietary Guidelines into healthy food choices that meet the recommended nutrient intakes at 12 different calorie levels (Table 1). This eating pattern includes a variety of nutrient-dense foods that are high in nutrients but low to moderate in energy content. Foods that are low in nutrient density supply calories but relatively small amounts of vitamins and minerals. The greater the consumption of foods that are low in nutrient density, the more difficult it is to consume enough nutrients without gaining weight.⁸

Intake Vs Need

Fruits, vegetables, whole grains, and fat-free or low-fat milk and milk products are important to a healthy diet and are excellent sources of essential nutrients. Diets rich in dietary fiber have a number of beneficial effects, including decreased risk of coronary heart disease and type 2 diabetes.⁸ In addition to fruits and vegetables, whole grains are an important source of fiber. Many Americans need to increase their dietary intake of calcium, potassium, fiber, magnesium, and vitamins A, C, and E. A low intake of fiber tends to reflect low consumption of whole grains, fruits, and vegetables. Studies show that low dietary intake of calcium and vitamin C are associated with periodontal diseases.^14,15 The USDA Food Guide provides adequate amounts of these nutrients.

Adults should follow a diet that is within the acceptable macronutrient distribution ranges (AMDR) for fat, carbohydrates, and protein, which are 20% to 35%, 45% to 65%, and 10% to 35% of total calories respectively. Fats and oils are part of a healthful diet. Most dietary fats should come from sources of polyunsaturated and monounsaturated fatty acids, such as liquid vegetable oils, walnuts, flaxseed, and fish that naturally contain more oil, eg, salmon, trout, and herring. Trans fat consumption should be kept as low as possible with no more than 10% of calories from saturated fat and no more than 300 mg of cholesterol daily. Carbohydrates are also important. Foods that provide carbohydrates—fruits, vegetables, and whole grains—are important sources of many nutrients and dietary fiber. With regard to protein, lean meats and poultry should be chosen.⁸

One Step at a Time

Many people set themselves up to fail in weight loss efforts by trying to attain unrealistic goals. One key recommendation of the Dietary Guidelines is to make small modest lifestyle changes, like eating fewer calories while increasing physical activity. The typical American diet usually provides calories in excess of energy requirements. Successful and sustainable weight loss and maintenance strategies require attention to both sides of the energy balance equation. Caloric expenditure needs to be in balance with caloric intake to maintain body weight and to achieve weight loss, it must be exceeded. To reverse the trend of obesity in the United States, many Americans need to eat fewer calories, be more active, and make wiser food choices. The healthiest way to reduce calorie intake is to reduce the consumption of added sugars, fats, and alcohol, which all provide calories but few or no essential nutrients.⁸

Americans also tend to be relatively inactive. In 2002, 25% of adults did not participate in any leisure time physical activities in the previous month¹⁶ and in 2003, 38% of high school students watched 3 or more hours of television per day.¹⁷ Regular physical activity is a key factor in achieving and maintaining a healthy body weight for adults and children. The most common barrier to physical activity is lack of time. Physical activity may include short 10 minute bouts of moderate intensity activity. Thirty minutes of at least moderate intensity physical activity, such as walking 3.5 miles per hour on most days, provides important short- and long-term health benefits for adults. Up to 60 minutes of at least moderate-intensity physical activity might be needed to avoid unhealthy weight gain. The amount of physical activity that weight-reduced adults need to avoid weight regain is estimated to be from 60 to 90 minutes daily at moderate-intensity.⁸ By increasing the level of physical activity, energy requirements are also increased, making it easier to plan a daily food intake pattern that meets the recommended nutrient requirements in accordance with the Dietary Guidelines for Americans.

Conclusion

Dental hygienists deliver comprehensive care with a keen focus on early detection, health promotion, and disease prevention. The dental office provides a powerful setting for interventions aimed at reducing the prevalence of obesity and its health consequences. Recommendations by a dental hygienist can be influential in patient/client dietary choices and physical activity habits. The integration of diet screening, basic dietary guidance, and referral into the dental hygiene practice are ways to improve oral and systemic health.

References

1. National Center for Health Statistics, NHANES 1999-2000 Data Files. Available at: http://www.cdc.gov/nchs/about/major/nhanes/nhanes99_00.htm. Accessed January 9, 2006.
2. Nishimura F, Iwamoto Y, Mineshiba J, Shimizu A, Soga Y, Murayama Y. Periodontal disease and diabetes mellitus: the role of tumor necrosis factor-a in a 2-way relationship. J Periodontol. 2003;74:97-102.
3. Saito T, Shimazaki Y, Sakamoto M. Obesity and periodontitis. N Engl J Med. 1998;339:482-483.
4. Reeves AF, Rees J, Schiff M, Hujoel P. Is there a relationship between obesity and chronic periodontitis among adolescents and young adults sampled in the Third National Health and Nutrition Examination Survey (NHANES III)? Presented at: Annual Meeting of the American Public Health Association; November 6-10, 2004; Washington, DC.
5. RAND Corporation. Obesity and Disability. Research Highlights 2004. Available at: a target=”_blank” href=”http://www.rand.org/health”>http://www.rand.org/health. Accessed January 9, 2006.
6. Al-Zahrani M, Bissada N, Borawski EA. Obesity and periodontal disease in young, middle-aged, and older adults. J Periodontol. 2003;74:610-615.
7. Iwamoto Y, Nishimura F, Nakagawa M, et al. The effect of antimicrobial periodontal treatment on circulating tumor necrosis factor-a and glycated hemoglobin level in patients with Type 2 Diabetes. J Periodontol. 2001;72:774-778.
8. US Department of Health and Human Services and US Department of Agriculture. Dietary Guidelines for Americans, 2005. 6th ed. Washington, DC: US Government Printing Office, January 2005.
9. US Department of Agriculture, Center for Nutrition Policy and Promotion, My Pyramid Food Guidance System, April 2005. Available at:  http://www.mypyramid.gov. Accessed January 9, 2006.
10. AQ-Ask Austin….10. American Dental Hygienists’Association: Public Health Policy on Nutrition. 14-94/26-74.
11. American Dental Hygienists’ Association (ADHA) Policy Manual. Chicago: ADHA; 2005: 14-94/26-74.
12. Boyd L, Dwyer J. Guidelines for nutrition screening, assessment, and intervention in the dental office. J Dent Hyg. 1998;72:31-44.
13. Palmer C. Diet and Nutrition in Oral Health. Saddle River, NJ: Prentice Hall, 2003.
14. US Department of Health and Human Services. Oral Health in America: A Report of the Surgeon General . Rockville, Md: US Department of Health and Human Services, National Institute of Dental and Craniofacial Research, National Institutes of Health, 2000.
15. Nishida M, Grossi S, Dunford R, Ho A, Trevisan M, Genco R. Calcium and the risk for periodontal disease. J Periodontol. 2000;71:1057-1066.
16. Nishida M, Grossi S, Dunford R, Ho A, Trevisan M, Genco R. Dietary vitamin C and the risk for periodontal disease. J Periodontol. 2000;71:1215-1223.
17. Behavioral Risk Factor Surveillance System. Surveillance for Certain Health Behaviors Among Selected Local Areas— United States, 2002. Available at: http://www.cdc.gov/brfss. Accessed January 9, 2006.
18. Healthy Youth! YRBSS: Youth Risk Behavior Surveillance System. Available at  http://www.cdc.gov/healthyyouth/yrbs. Accessed January 9, 2006.

From Dimensions of Dental Hygiene. January 2006;4(1):16-17, 35.