A systematic review of the association between food insecurity and behaviours related to caries development in adults and children in high-income countries

Objectives

To synthesize and appraise the evidence regarding the relationship between food insecurity and behaviours associated with dental caries development in adults and children in high-income countries.

Methods

A systematic review including observational studies assessing the association between food insecurity and selected dietary (free sugar consumption) and non-dietary factors (tooth brushing frequency; use of fluoridated toothpaste; dental visiting; oral hygiene aids; type of toothbrush used; interdental cleaning frequency and mouthwash use) related to dental caries development in adults and children in high-income countries. Studies specifically looking at food insecurity during the COVID-19 pandemic were excluded. Searches were performed in MEDLINE, Embase, Global Health and Scopus from inception to 25 May 2023. Two authors screened the search results, extracted data and appraised the studies independently and in duplicate. Study quality was assessed using the Newcastle–Ottawa Scale (with modifications for cross-sectional studies). Vote counting and harvest plots provided the basis for evidence synthesis.

Results

Searches identified 880 references, which led to the inclusion of 71 studies with a total of 526 860 participants. The majority were cross-sectional studies, conducted in the USA and reported free sugar consumption. Evidence for the association between food insecurity and free sugar intake from 4 cohort studies and 61 cross-sectional studies including 336 585 participants was equivocal, particularly in the sugar-sweetened beverage (SSB) consumption post-hoc subgroup, where 20 out of 46 studies reported higher SSB consumption in food insecure individuals. There was consistent, but limited, evidence for reduced dental visiting in adults experiencing food insecurity compared to food secure adults from 3 cross-sectional studies including 52 173 participants. The relationship between food insecurity and dental visiting in children was less clear (3 cross-sectional studies, 138 102 participants). A single cross-sectional study of 3275 children reported an association between food insecurity and reported failure to toothbrush the previous day.

Conclusions

This review did not identify clear associations between food insecurity and behaviours commonly implicated in the development of dental caries that would explain why individuals experiencing food insecurity are more likely to have dental caries than those who have food security. There was some evidence of decreased dental visiting in adults experiencing food insecurity. Common methodological weaknesses across the evidence base related to the selection of participants or control of potentially confounding variables. Consequently, the quality of evidence for all outcomes was downgraded to very low. More research is needed to explore access to oral hygiene products and household environments conducive to habitual oral self-care in food insecure populations.