Consumption of green tea but not coffee is associated with the oral health-related quality of life among an older Japanese population: Kyoto-Kameoka cross-sectional study.

BACKGROUND/OBJECTIVES: The consumption of both green tea and coffee is known to induce positive health effects; however, it remains unclear whether there is an association between the consumption of these beverages and oral health-related quality of life (OHRQoL). Thus, the present study investigated the relationship between the consumption of green tea and coffee and OHRQoL. SUBJECTS/METHODS: We analyzed cross-sectional baseline data in 2012. The subjects were 7514 Japanese participants (3563 men, 3951 women; >/=65 years of age). Each subject completed a validated self-administered questionnaire that included items on the frequency of the consumption of green tea and coffee. OHRQoL was evaluated using the self-reported General Oral Health Assessment Index (GOHAI), which assesses oral health problems in older adults. A GOHAI score <50 points was defined as a poor OHRQoL. RESULTS: Following adjustment for age, body mass index, total energy intake, alcohol, smoking, medication use, coffee, and fruit and vegetable consumption, increased consumption of green tea showed a strong positive association with the GOHAI score in both men and women (P(trend) < 0.001 in both). In contrast, after adjusting for all factors, no statistically significant association was observed between coffee consumption and the GOHAI score in men (P(trend) = 0.538) or women (P(trend) = 0.607). The respective multivariate-odds ratios (95% confidence intervals) for a poor OHRQoL associated with green tea consumption frequencies of none, <1 cup/day, 1-2 cups/day, and >/=3 cups/day were 1.00, 1.01 (0.80-1.27), 0.95 (0.74-1.21), and 0.78 (0.61-0.99) (P(trend) = 0.024) in men, and 1.00, 1.19 (0.90-1.57), 0.98 (0.74-1.29), and 0.86 (0.67-1.12) (P(trend) = 0.014) in women. CONCLUSIONS: Regardless of sex, green tea consumption was positively associated with the GOHAI score. Therefore, >/=3 cups/day of green tea may reduce the risk of a poor OHRQoL, especially in men.