Healthy Mouth, Healthy Body

Gum diseases are extremely common. They happen when plaque, a sticky film of bacteria, builds up on teeth. The earliest stages of gum disease, known as gingivitis, are reversible if treated. However, some people develop periodontitis, a chronic destructive form of gum disease that can lead to tooth loss. See blog post Gum Health – Gingivitis and Periodontitis for more information about these diseases and what to do to prevent them. And see blog post Nutrition for Dental Health for information about which vitamins and minerals are needed for good oral health.

Population studies, clinical studies, and in vitro animal studies underscore the link between oral health and systemic health. Evidence suggests that periodontal health can increase the risk of serious health problems and is associated with diabetes, metabolic syndrome, obesity, eating disorders, liver disease, cardiovascular disease, Alzheimer’s disease, rheumatoid arthritis, adverse pregnancy outcomes, and cancer. Proposed mechanisms that mediate the connection between oral and systemic health include genetic factors, environmental factors (stress, smoking, consumption of highly processed foods, nutrient deficiencies), medications, microbial dysbiosis and an altered immune response. Thus, in a susceptible person, these predisposing factors may trigger the onset of periodontal disease and subsequent systemic diseases. Here are a few common health conditions linked to poor oral health:

Dementia

In the last decade, increasing evidence has pointed to a microbial and inflammatory origin for Alzheimer’s disease with the discovery of oral and airway bacteria, viruses, and fungal species in the brains of patients with Alzheimer’s disease. Periodontitis (gum disease), which is caused by pathogenic microorganisms, can cause systemic, chronic inflammatory responses that have significant implications for the development of Alzheimer’s disease (1).

Data indicate a possible association of specific periodontal pathogens with cognitive impairment.  Preliminary findings point to a possible role of an altered salivary microbiome as a causal link between chronic periodontitis and cognitive impairment in Alzheimer’s disease (2).

Covid-19

There is evidence that poor oral health is a risk factor for complications in those with severe Covid, especially in those with conditions such as diabetes, high blood pressure or cardiovascular disease, as these can be aggravated by poor oral health and are themselves risk factors for severe Covid (3).

Covid-19 is associated with an exacerbated inflammatory response that can be fatal. Systemic inflammation is also a major characteristic of periodontitis. Research shows that periodontitis is associated with higher risk of ICU admissions, need for assisted ventilation and death in Covid-19 patients (4).

There may be several reasons for this association: people with severe Covid have elevated levels of an inflammatory marker called CRP and may also develop a cytokine storm where the immune system goes into overdrive and harms the body’s tissues in its attempts to fight the virus. People with poor oral health may also have elevated levels of CRP and cytokines. In other words gum disease can trigger an immune response similar to that of Covid. If the two diseases are encountered at the same time it’s possible this could tip the immune response into harming the body’s tissues, leading to worse outcomes.

Also, having uncontrolled bacteria in the mouth raises the risk of getting a joint Covid-bacterial infection in the airway or lungs. It’s likely that other factors are also exacerbating the link between oral health and Covid.

Cardiovascular Disease

Many studies suggest an association between periodontal disease and ischaemic heart disease, cerebrovascular disease, heart failure, atrial fibrillation and peripheral artery disease. Systemic inflammation is likely to play a major role in this association. Evidence suggests that periodontal inflammation triggers a systemic inflammatory state that promotes atheroma plaque development and progression. There are other studies that show a clear relationship between periodontal disease severity, elevations of inflammatory markers, and the presence of atherosclerosis (5).

Type 2 Diabetes

Diabetes can worsen oral infections and vice versa (6). People with uncontrolled diabetes are at greater risk for several oral health problems, particularly periodontal disease and oral infections (6,7). Studies suggest that periodontal treatment may improve glycaemic control in patients with diabetes (8). Good oral hygiene and regular dental visits are recommended to prevent and manage oral health problems in those with diabetes.

Cancer

Gum disease is linked to a greater risk of developing certain types of cancer including oesophageal cancer and stomach cancer. It’s thought this has to do with inflammation which is a factor in both gum disease and cancer. Frequent toothbrushing is associated with a reduced risk for gastrointestinal cancer (9).

References

1. Curr Opin Neurol. 2020 Apr;33(2):230-238. Linking mechanisms of periodontitis to Alzheimer’s disease. Sadrameli M et al.

2. Wien Klin Wochenschr. 2020 Sep;132(17-18):493-498. Knock-on effect of periodontitis to the pathogenesis of Alzheimer’s disease? Leblhuber F et al.

3. Periodontol 2000. 2021 Oct;87(1):11-16. Oral health’s inextricable connection to systemic health: Special populations bring to bear multimodal relationships and factors connecting periodontal disease to systemic diseases and conditions. Kapila YL.

4. J Clin Periodontol. 2021 Apr;48(4):483-491. Association between periodontitis and severity of COVID-19 infection: A case-control study. Marouf N et al.

5. Heart Lung Circ. 2018 Nov;27(11):1327-1334. Periodontal Disease, Systemic Inflammation and the Risk of Cardiovascular Disease. Carrizales-Sepulveda EF et al.

6. 2015 May;49(1):27-34. Diabetes mellitus and oral health. Kudiyirickal MG et al.

7. MC Public Health. 2018 May 2;18(1):577. Oral health knowledge, attitudes and care practices of people with diabetes: a systematic review. Poudel P et al.

8. Braz Oral Res. 2020 Apr 9;34(supp1 1):e026. Periodontal disease and its impact on general health in Latin America. Section V: Treatment of periodontitis. Guimaraes Fischer R et al.

9. J Clin Periodontol. 2020 Jul;47(7):796-808. Oral health and gastrointestinal cancer: A nationwide cohort study. Lee K et al.