Oral health and cognitive function in the Third National Health and Nutrition Examination Survey (NHANES III).
OBJECTIVE
To investigate the association between oral health and cognitive function in early-, mid-, and late-adult life.


METHODS
A secondary analysis was carried out of a large, well-characterized community sample (NHANES III). Analyzed variables included three measures of oral health (gingival bleeding, loss of periodontal attachment, loss of teeth) and three measures of cognitive function: the Symbol Digit Substitution Test (SDST), the Serial Digit Learning Test (SDLT) (both in 5138 participants aged 20-59 years), and a Story Recall test (in 1555 participants aged >or=70 years). Other covariates in linear regression models included age, gender, ethnicity, education and poverty, and cardiovascular risk factors.


RESULTS
Worse scores on all three measures of oral health status were significantly associated with poorer performance on all three measures of cognitive function after adjustment for age. Education was an important confounding factor. However, after full adjustment for all other covariates, gingival bleeding (%) and loss of periodontal attachment (%) remained associated with relative impairment on SDST score (B coefficients both = 0.003), and gingival bleeding was associated with relative impairment on SDLT (B = 0.017). No effect modification by age was observed.


CONCLUSIONS
Poor oral health is associated with worse cognitive function throughout adult life. This may, in part, be accounted for by early life education and social status. However, the possibility of direct causal pathways requires further investigation.
Section of Epidemiology, Institute of Psychiatry, London, UK. r.stewart@iop.kcl.ac.uk
Robert
R
Stewart
Wael
W
Sabbah
Georgios
G
Tsakos
Francesco
F
D'Aiuto
Richard G
RG
Watt
D000328:Adult; D000367:Age Factors; D000368:Aged; D003072:Cognition Disorders / Q000453:epidemiology* / Q000523:psychology; D015897:Comorbidity; D005260:Female; D005884:Gingival Hemorrhage / Q000453:epidemiology* / Q000523:psychology; D006801:Humans; D008297:Male; D011939:Mental Recall; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D009749:Nutrition Surveys; D009909:Oral Health; D017622:Periodontal Attachment Loss / Q000453:epidemiology* / Q000523:psychology; D011594:Psychometrics; D013223:Statistics as Topic; D016388:Tooth Loss / Q000453:epidemiology* / Q000523:psychology; D055815:Young Adult