Oral health and multimorbidity: is diet the chicken or the egg?

Oral health is a critical component of overall health and well-being, not just the absence of disease. The objective of this review paper is to describe relationships among diet, nutrition and oral and systemic diseases that contribute to multimorbidity. Diet- and nutrient-related risk factors for oral diseases include high intakes of free sugars, low intakes of fruits and vegetables and nutrient-poor diets which are similar to diet- and nutrient-related risk factors for systemic diseases. Oral diseases are chronic diseases. Once the disease process is initiated, it persists throughout the lifespan. Pain and tissue loss from oral disease leads to oral dysfunction which contributes to impaired biting, chewing, oral motility and swallowing. Oral dysfunction makes it difficult to eat nutrient-dense whole grains, fruits and vegetables associated with a healthy diet. Early childhood caries (ECC) associated with frequent intake of free sugars is one of the first manifestations of oral disease. The presence of ECC is our 'canary in the coal mine' for diet-related chronic diseases. The dietary sugars causing ECC are not complementary to an Eatwell Guide compliant diet, but rather consistent with a diet high in energy-dense, nutrient-poor foods - typically ultra-processed in nature. This diet generally deteriorates throughout childhood, adolescence and adulthood increasing the risk of diet-related chronic diseases. Recognition of ECC is an opportunity to intervene and disrupt the pathway to multimorbidities. Disruption of this pathway will reduce the risk of multimorbidities and enable individuals to fully engage in society throughout the lifespan.