The Association between Habitual Green Tea Consumption and Comprehensive Frailty as Assessed by Kihon Checklist Indexes among an Older Japanese Population.

BACKGROUND: It is unclear whether habitual green tea consumption is related to comprehensive frailty. OBJECTIVES: We conducted this study to investigate this relationship among an elderly Japanese population. METHODS: This was a cross-sectional study of baseline data from 2012. The study included 5668 Japanese participants (2766 men and 2902 women aged 65 years or older). The subjects completed a validated self-administered food frequency questionnaire that included questions on their green tea consumption. We evaluated comprehensive frailty using a 25-item Kihon Checklist (KCL), which comprised seven domains (instrumental activities of daily living (IADL), physical function, malnutrition, oral or eating function, socialization and housebound, cognitive function, and depression). Frailty was defined as a KCL score greater than or equal to seven. RESULTS: We found that a higher consumption of green tea was associated with a lower prevalence of comprehensive frailty in both sexes. Further age-stratified analysis showed that a higher consumption of green tea among women was associated with a lower prevalence of comprehensive frailty, regardless of age. In men, however, this association was found only in the older age groups. An analysis of the association between green tea consumption and the frailty subdomains showed that green tea consumption was associated with a lower prevalence of oral dysfunction and cognitive problems in both sexes. In addition, only in women was higher green tea consumption found to be associated with a lower prevalence of IADL and mobility-related disability problems. CONCLUSIONS: Green tea consumption is inversely associated with the prevalence of comprehensive frailty in Japanese men and women. Longitudinal studies are required to confirm this association.

Association between habitual coffee consumption and skeletal muscle mass in middle-aged and older Japanese people.

AIMS: Coffee consumption has been suggested, in animal studies, to inhibit the progression of sarcopenia, possibly through its anti-inflammatory effects; however, few studies have been carried out in humans. We aimed to examine whether coffee consumption was related to indicators of sarcopenia in a Japanese population, and whether the association was mediated by reduced inflammation. METHODS: This study was a cross-sectional design. Participants were community residents (n = 6369) aged 45-74 years. We measured skeletal muscle mass index (SMI; kg/m2 ) by a bioelectrical impedance method, and grip strength with a Smedley-type dynamometer. Habitual coffee consumption was assessed by a self-administered questionnaire. Serum high-sensitivity C-reactive protein was measured as an inflammatory marker. The association between habitual coffee consumption and SMI or grip strength was analyzed with a linear regression model adjusted for covariates. RESULTS: A significant positive association was found between coffee consumption and SMI (men: ß = 0.023; Ptrend  = 0.004, women: ß = 0.011; Ptrend  = 0.012). Further adjustment for high-sensitivity C-reactive protein did not materially alter the results (men: ß = 0.023; Ptrend  = 0.005, women: ß = 0.009; Ptrend  = 0.024). The relationship between coffee consumption and grip strength did not reach statistical significance; however, a positive trend was observed (men: ß = 0.208; Ptrend  = 0.085, women: ß = 0.092; Ptrend  = 0.167). CONCLUSIONS: We found that coffee consumption was positively associated with SMI independently of inflammation in middle-aged and older Japanese people. Reduced inflammation by coffee does not seem to be an important mediator, and further investigations are required to explore the mechanisms of this association. Geriatr Gerontol Int 2021; 21: 950-958.

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 (Ptrend < 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 (Ptrend = 0.538) or women (Ptrend = 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) (Ptrend = 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) (Ptrend = 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.

Mitochondrial DNA 5178 C/A polymorphism modulates the effects of coffee consumption on elevated levels of serum liver enzymes in male Japanese health check-up examinees: an exploratory cross-sectional study.

BACKGROUND: Longevity-associated mitochondrial DNA 5178 cytosine/adenine (Mt5178 C/A) polymorphism modulates the effects of coffee consumption on the risk of hypertension, dyslipidemia, and abnormal glucose tolerance. The objective of this study was to investigate whether Mt5178 C/A polymorphism modifies the effects of coffee consumption on abnormally elevated levels of serum liver enzymes in male Japanese health check-up examinees. METHODS: A total of 421 male subjects (mean age ± SD, 54.1 ± 7.7 years) were selected from among individuals visiting the hospital for regular medical check-ups. After Mt5178 C/A genotyping, a cross-sectional study assessing the joint effects of Mt5178 C/A polymorphism and coffee consumption on elevated levels of serum aspartate aminotransferase (AST), serum alanine aminotransferase (ALT), and serum gamma-glutamyl transpeptidase (GGT) was then conducted. RESULTS: For men with Mt5178C, after adjustment for age, body mass index, alcohol consumption, habitual smoking, green tea consumption, antihypertensive treatment, and antidiabetic treatment, elevated levels of serum AST, as defined as ≥30 U/L; those of serum ALT, as defined as ≥25 U/L; or those of serum GGT, as defined as ≥60 or >51 U/L, may depend on coffee consumption (P for trend = 0.013, P for trend <0.001, P for trend = 0.002, and P for trend <0.001, respectively). On the other hand, no significant joint effects of Mt5178A genotype and coffee consumption on elevated levels of serum liver enzymes were observed. CONCLUSIONS: The present results suggest that Mt5178 C/A polymorphism modifies the effects of coffee consumption on abnormally elevated levels of serum liver enzymes in male Japanese health check-up examinees.

Longevity-associated mitochondrial DNA 5178 C/A polymorphism modulates the effects of coffee consumption on erythrocytic parameters in Japanese men: an exploratory cross-sectional analysis.

BACKGROUND: Mitochondrial DNA 5178 cytosine/adenine (Mt5178 C/A) polymorphism reportedly modulates the effects of coffee consumption on the risk of hypertension, dyslipidemia and abnormal glucose tolerance. The objective of this analysis was to investigate whether Mt5178 C/A polymorphism modifies the effects of coffee consumption on erythrocytic parameters in male Japanese health check-up examinees. METHODS: A total of 436 men (mean age ± standard deviation, 54.1 ± 7.8 years) were selected from among individuals visiting the hospital for regular medical check-ups. After Mt5178 C/A genotyping, an exploratory cross-sectional analysis assessing the joint effects of Mt5178 C/A polymorphism and coffee consumption on red blood cell counts, hematocrit and hemoglobin was conducted. RESULTS: For Mt5178C genotypic men, after adjustment for age, body mass index, alcohol consumption, habitual smoking and green tea consumption, coffee consumption significantly decreased red blood cell counts (P for trend = 0.022) and hemoglobin (P for trend = 0.035). The risk of anemia, defined as hemoglobin of <14 g/dL, after the aforementioned adjustment, appeared to depend on coffee consumption (P for trend = 0.078), and the adjusted odds ratio for anemia was significantly higher in men who consumed ≥4 cups of coffee per day than in those who consumed <1 cup per day (odds ratio = 3.771, 95% confidence interval: 1.088 to 13.06, P = 0.036). For Mt5178A genotypic men, coffee consumption possibly reduced the risk of anemia (P for trend = 0.049). However, after the aforementioned adjustment, the statistical significance disappeared (P for trend = 0.137). CONCLUSIONS: This exploratory cross-sectional analysis suggests that Mt5178 C/A polymorphism modulates the effects of coffee consumption on erythrocytic parameters and the risk of anemia in male Japanese health check-up examinees.

Unexpected combined effects of NADH dehydrogenase subunit-2 237 Leu/Met polymorphism and green tea consumption on renal function in male Japanese health check-up examinees: a cross-sectional study.

BACKGROUND: NADH dehydrogenase subunit-2 237 leucine/methionine (ND2-237 Leu/Met) polymorphism is associated with longevity in Japanese. A previous study has shown that ND2-237 Leu/Met polymorphism modulates the effects of green tea consumption on risk of hypertension. For men with ND2-237Leu, habitual green tea consumption may reduce the risk of hypertension. Moreover, there is a combined effect of ND2-237 Leu/Met polymorphism and alcohol consumption on risk of mildly decreased estimated glomerular filtration rate (eGFR) (<90 ml/min/1.73 m2). Several beneficial effects of green tea on the kidney have been reported. The objective of this study was to investigate whether ND2-237 Leu/Met polymorphism modifies the effects of green tea consumption on risk of mildly decreased eGFR in male Japanese health check-up examinees. RESULTS: For ND2-237Leu genotypic men, after adjustment for confounding factors, green tea consumption may increase the risk of mildly decreased eGFR (P for trend = 0.016). The adjusted odds ratio (OR) for mildly decreased eGFR was significantly higher in subjects with ND2-237Leu who consume ≥6 cups of green tea per day than those who consume ≤1 cup of green tea per day (adjusted OR = 5.647, 95% confidence interval: 1.528-20.88, P = 0.009). On the other hand, for ND2-237Met genotypic men, green tea consumption does not appear to determine the risk of mildly decreased eGFR. CONCLUSION: The present results suggest that ND2-237 Leu/Met polymorphism unexpectedly modifies the effects of green tea consumption on eGFR and the risk of mildly decreased eGFR in male Japanese subjects.