The connection between poor oral health and metabolic disease: the sugar link theory.

The purpose of this narrative review is to explore the idea that habitual and excessive intake of sugar and ultraprocessed foods (UPFs) may be the link between poor oral health (specifically dental caries) and metabolic disease and the common upstream factor that explains the association between these conditions. This proposed sugar link theory posits a parallel between declines in oral health and systemic health, beginning with the detrimental impacts of sugar and UPFs on the oral and gut microbiomes (dysbiosis). The resulting ecologic shifts produce biochemical alterations that lead to oral and systemic disease. One way for dentists to mitigate the worldwide impact of dental caries and metabolic disease is to encourage their patients to avoid habitual and excessive intake of sugar and UPFs.