To investigate the longitudinal relationship between the intake of dietary antioxidants and periodontal disease in community-dwelling older Japanese.

A retrospective cohort study, with a follow-up of 2 years (2003–2005). Intakes of dietary antioxidants (vitamin C, vitamin E, α-carotene and β-carotene) were assessed with a validated FFQ. Participants were classified by tertile of antioxidant intake. Full-mouth periodontal status, measured as the clinical attachment level, was recorded at baseline and follow-up examinations. Periodontal disease progression was considered as loss of attachment of 3 mm or greater over the study period at the interproximal site for each tooth. Finally, the number of teeth with periodontal disease progression per person was calculated and was used as the outcome. Poisson regression analysis was conducted, with dietary antioxidants as the main exposure, to estimate their influence on the number of teeth with periodontal disease progression.

Niigata City (Japan).

Dentate individuals aged 75 years in 2003, for whom data were available, were included in the analyses (n 264).

A higher intake of dietary antioxidants was inversely associated with the number of teeth with periodontal disease progression, controlling for other variables. The multivariate-adjusted incidence rate ratios in the first, second and third tertiles were 1·00, 0·76 (95 % CI 0·60, 0·97) and 0·72 (95 % CI 0·56, 0·93) for vitamin C; 1·00, 0·79 (95 % CI 0·62, 0·99) and 0·55 (95 % CI 0·42, 0·72), for vitamin E; and 1·00, 1·02 (95 % CI 0·81, 1·29) and 0·73 (95 % CI 0·56, 0·95) for β-carotene.

The study results suggest that higher intake of antioxidants may mitigate periodontal disease in community-dwelling older Japanese.

Low Ca intake is common among Japanese women, but its effect on bone metabolism has not been fully elucidated. The aim of the present study was to determine the relationship between Ca intake and serum markers of bone turnover in postmenopausal Japanese women.

A cross-sectional study.

A community setting.

Subjects were 595 home-dwelling postmenopausal Japanese women. Ca intake was assessed by a validated FFQ. Serum type I collagen cross-linked N-telopeptides (NTX) and osteocalcin were measured as markers of bone turnover. The relationships between demographic characteristics, lifestyles, serum Ca, vitamin D and intact serum parathyroid hormone and bone turnover were also assessed.

The average age of the subjects was 64·5 (sd 5·8) years and the mean Ca intake was 527 (sd 160) mg/d. Ca intake was significantly associated with serum NTX (P = 0·0104), but not with serum osteocalcin. Mean serum NTX concentration in the lowest quartile of Ca intake (<417 mg/d) was significantly higher than in the fourth, referent quartile. Among these Japanese postmenopausal women, very low Ca intake (less than ∼400 mg/d) was associated with increased bone resorption but not bone formation.

Increased bone resorption may be one mechanism by which this Ca-depleted population normalizes bone metabolism and prevents osteoporosis.