Background We investigated the associations of poor oral health with dietary quality and intake in older people. We also examined whether changes in dietary quality can influence the risk of oral health problems.

Methods Data come from the British Regional Heart Study (BRHS) and the Health, Aging and Body Composition (HABC) Study. The BRHS included older men from 24 British towns aged 71–92 years in 2010–12 (n=2,147). The HABC Study, included 3,075 American men and women aged 71–80. In both studies, measures of oral health included tooth loss, periodontal disease, dry mouth, and self-rated oral health. Dietary data included dietary quality (Elderly Dietary Index in the BRHS, and Healthy Eating Score in the HABC Study) and intake (processed meat, calories from fat, protein and fruits and vegetables). Additionally in the BRHS, change in dietary quality was assessed over 10 years from 1998–2000 (age 60–79 years) to 2010–2012 (71–92 years).

Results In the BRHS, tooth loss, fair/poor self-rated oral health and accumulation of oral health problems were associated with poor dietary quality, after adjustment for age, social class, smoking, alcohol, history of cardiovascular disease (CVD) and diabetes, body mass index (BMI) and energy intake. Similar associations were observed for high intake of processed meat. Accumulation of oral health problems and self-rated oral health were associated with being in the top quartile of percentage of calories from saturated fat (fair/poor self-rated oral health, odds ratio (OR)=1.34, 95% CI 1.02–1.77) after adjustment for confounders. In the HABC study, no significant associations were observed between poor oral health and dietary quality after full adjustment. In the fully-adjusted model (age, gender, race, education, smoking, alcohol, history of CVD and diabetes, BMI and energy intake), periodontal disease was associated with the top quartile of percentage of calories from saturated fat (OR=1.48, 95%CI 1.09–2.01). In the BRHS, persistent low dietary quality over 10 years (from age 60–79 to 71–92 years), was associated with higher risk of tooth loss and accumulation of oral health problems at 71–92 years.

Conclusion Older individuals with oral health problems had poorer diets and consumed fewer nutrient-rich foods. Moreover, persistent poor dietary quality in older ages was associated with oral health problems later in life, suggesting bi-directional associations between oral health and dietary intake in older age. Improved management of nutrition and oral health are both important aspects of the health of older populations.