Apart from the impact that tooth loss has on a person’s quality of life, affecting such aspects as appearance, self-esteem, effective social interactions, and enjoyment derived from food, there also exists the real concern that healthy nutrition is detrimentally influenced by the lack of teeth,1-3 particularly in the elderly.4,5

Masticatory function is dependent on dentition status, and because tooth loss decreases chewing ability, unfavorable changes in food choices and nutrient intake can occur. The resulting poor dietary habits have been implicated in causing systemic health problems;1,2,6 numerous associations between diet and disease have been reported. For example, it has been demonstrated that a diet high in fat and cholesterol increases the risk of cardiovascular disease (CVD), while diets low in fiber, fruits, and vegetables may cause an increased cancer risk.2

Dentition Status and Food Consumption

A large-scale investigation by Joshipura, et al.1 examined the association between the number of teeth and nutrient intake in male health professionals 40 to 80 years of age. In general, it was found that as the number of natural teeth of participants decreased, so did their average dietary intake of fiber, carotene, vegetables, and fruits. Conversely, the intake of calories, saturated fat, and cholesterol increased with decreasing numbers of teeth.  Although the overall differences in diet between the edentate and dentate participants were significant but small, the detrimental effects of tooth loss could lead to increased disease risk over time. For instance, it was hypothesized that a one-gram decrease in dietary fiber intake for the edentate compared to the dentate group could lead to an approximate two-percent increased risk of myocardial infarction.1 A separate large-scale study of U.S. women showed similar results; edentulous women had a significantly higher intake of saturated and trans fats, cholesterol and vitamin B12, and lower intake of polyunsaturated fat, fiber, vegetables, fruits, and a number of vitamins compared to women having 25–32 teeth. Further, in a longitudinal aspect of the investigation, women who lost more teeth over the duration of the study showed unhealthy dietary changes, avoiding hard-to-chew foods like raw vegetables and fruits.

Investigating whether the wearing of dentures affected nutrition, Krall, et al.2 showed that chewing was significantly impaired in a cohort of male veterans living in the Boston area who had complete or removable partial dentures, as compared with those whose dentitions were intact. Consumption of protein and fiber tended to decrease with progressively impaired dentition status, with full denture wearers having significantly reduced dietary fiber intake compared to any other group2. In contrast to the study reported above by Joshipura, et al.,1 consumption of total calories tended to decrease with poorer dentition, explained by the study investigators as possibly attributed to socioeconomic factors of the respective study populations. However, although the full-denture group consumed significantly fewer calories than the other groups, their percentage of calories from fat tended to increase2.

Finally, a study by Sheiham, et al.5 was designed to assess whether the oral condition of people 65 years or older was related to the intake of selected nutrients. For most nutrients, the researchers generally found that dentate participants had higher nutrient intakes than the edentulous participants. Statistically significant associations with dental status were present for the intake of protein, intrinsic and milk sugars, fiber, calcium, non-heme iron, and vitamins C and E.5 All of these studies provide evidence that nutrient intake is associated with dental status. Furthermore, many of the foods avoided by people with poor dentition protect against diseases such as CVD, ischemic stroke, and metabolic syndrome (MetS).

Systemic Disease and Nutrient Intake

Cardiovascular Disease and Ischemic Stroke. Studies have shown an inverse association between the intake of fruits and vegetables — in particular, green leafy vegetables and citrus fruits — and the risk of CVD3,7 and ischemic stroke.8 The constituents of fruits and vegetables that are believed to protect against these diseases include vitamins (including B6, B12, C, D, and E), potassium, folate, fiber, and flavanoids.7,8 A recent evaluation9 of one study3 accepts that tooth loss is associated with reported diet changes, and that these changes in diet could have an effect on systemic health, although the experimental evidence to make a causal link is not present.

Metabolic Syndrome. MetS is a disease that has resulted from the decrease in exercise and increase in caloric intake that has occurred in the American population over the last 30 years. The disease can consist of the following characteristics: abdominal obesity; raised triglyceride level; reduced high-density lipoprotein cholesterol levels; hypertension; and impaired fasting glucose.6 Each of these characteristics can result in atherosclerosis, increasing the risk of myocardial infarction and stroke. The retention of healthy teeth and gums is vital for MetS sufferers due to their tendency to develop vascular disease. As previously mentioned, people who lose teeth, especially the posterior grinding teeth, may alter their food choices, opting for a diet associated with an increased risk of CVD. Furthermore, edentate people have been found to have a significantly higher body mass index (BMI) compared with similar dentate people, and these higher BMI levels appear to occur from an increase in consumption of calorie-rich, soft, sweet foods that promote obesity. Removable partial and complete dentures do not appear to compensate for the chewing efficiency of lost teeth, nor do they significantly improve nutritional intake. However, there is some limited evidence of improved nutritional intake in patients who have received dental implants. The increased risk of CVD in patients with MetS makes it vital for dentists to consider treatments that attempt to retain the natural dentition, maximizing mastication efficiency, and increasing the likelihood of consuming foods that will not foster arthrosclerosis.6

Conclusion

Oral health and dentition status can have an impact on food choice and on nutrient intake, with edentulous people consuming fewer fruits and vegetables and more saturated fat and cholesterol. These dietary changes may be related to an increased risk for cardiovascular and metabolic diseases. Due to the high prevalence of tooth loss among older adults, even a small increase in the risk of developing systemic disease owing to poor dentition could have a significant impact. In this light, it is advised that dietary recommendations be integrated into dental visits, especially for the elderly, to benefit patient health. Prevention of tooth loss and replacement of teeth with dental implants may help people maintain a healthy diet, which can potentially reduce the incidence of diet-related chronic systemic disease.

References

1. Joshipura KJ, Willett WC, Douglass CW. The impact of edentulousness on food and nutrient intake. JADA 1996;127(4):459-467.
2. Krall E, Hayes C, Garcia R. How dentition status and masticatory function affect nutrient intake. JADA 1998;129(9):1261-1269.
3. Hung HC, Colditz G, Joshipura KJ. The association between tooth loss and the self-reported intake of selected CVD-related nutrients and foods among US women. Community Dent Oral Epidemiol 2005;33(3):167-173.
4. Sheiham A, Steele JG, Marcenes W, Tsakos G, Finch S, Walls AW. Prevalence of impacts of dental and oral disorders and their effects on eating among older people; A national survey in Great Britain. Community Dent Oral Epidemiol 2001;29(3):195-203.
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6. Friedlander AH, Weinreb J, Friedlander I, Yagiela JA. Metabolic syndrome: Pathogenesis, medical care and dental implications. JADA 2007;138(2):179-187.
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8. Joshipura KJ, Ascherio A, Manson JE, Stampfer MJ, Rimm EB, Speizer FE, et al. Fruit and vegetable intake in relation to risk of ischemic stroke. JAMA 1999;282(13):1233-1239.
9. Merchant AT. Losing teeth leads to an unhealthy diet associated with cardiovascular disease risk. J Evid Based Dent Pract 2006;6(2):187-188.