Tea consumption is inversely associated with depressive symptoms in the elderly: A cross-sectional study in eastern China

Long-Term Consumption of Green Tea Can Reduce the Degree of Depression in Postmenopausal Women by Increasing Estradiol

Postmenopausal women face a higher risk of depression due to a combination of social and physiological factors. As a beverage rich in a variety of bioactive substances, green tea has significant effects on metabolism, inflammation and endocrine, and may reduce the risk of depression, but few studies have looked at the effects of green tea on postmenopausal women. Therefore, we designed this study to investigate the effects of long-term green tea consumption on inflammation, endocrine and depression levels in postmenopausal women. We investigated a tea-producing village and eventually included 386 postmenopausal women, both in the tea drinking and control groups. The results showed that there were significant differences in the degree of insomnia, degree of depression, BMI, SII and estradiol between the two groups. And, green tea consumption may reduce the risk of depression through the mediating pathway of sleep, SII and estradiol. In summary, long-term green tea consumption can reduce the risk of depression in postmenopausal women by reducing inflammation and increasing estradiol. This kind of living habit deserves further promotion.

The role of lifestyle factors in cognitive health and dementia in oldest-old: A systematic review

Oldest-old is the fastest growing segment of society. A substantial number of these individuals are cognitively impaired or demented. Given the lack of a cure, attention is directed to lifestyle interventions that could help alleviate the stress in patients, their families, and society. The aim of this review was to identify lifestyle factors with important roles in dementia prevention in oldest-old. Searches were conducted in PubMed, EMBASE, Scopus and Web of Science. We identified 27 observational cohort studies that met the inclusion criteria. Results showed that eating a healthy diet with plenty of fruits and vegetables, and participation in leisure and physical activities may protect against cognitive decline and cognitive impairment among oldest-old regardless of the APOE genotype. Combined lifestyles may generate multiplicative effects than individual factors. This is the first review known to systematically examine the association between lifestyle and cognitive health in oldest-old. Lifestyle interventions for diet, leisure, or a combination of lifestyles could be beneficial for cognitive function in oldest-old. Interventional studies are warranted to strengthen the evidence.

Association between dietary caffeine, coffee, and tea consumption and depressive symptoms in adults: A systematic review and dose-response meta-analysis of observational studies

Background

Recent studies have reported an association between dietary caffeine intake (coffee and tea) and the presence of depressive symptoms. However, the findings are not conclusive.

Purpose

This study aimed to examine the correlation between the consumption of dietary caffeine (coffee and tea) and the presence of depressive symptoms in adults.

Methods

PubMed and Scopus databases were searched until December 2021. Two investigators analyzed data from identified studies and rated the quality of the evidence using the GRADE approach. Using the random-effects models, we estimated the relative risks (RRs) and 95% confidence intervals (CIs). We also modeled the dose-response associations through a one-stage, weighted mixed-effects meta-analysis.

Results

A total of 29 eligible studies included a total of 422,586 participants. On comparing the highest with the lowest category in cohort studies, we identified an inverse association between the intake of coffee and depressive symptoms (RR: 0.89, 95%CI: 0.82-0.95; I² = 63.7%, GRADE = low). There was a 4% reduction in the risk of depression associated with an increase in coffee intake of 240 ml/day (RR: 0.96, 95%CI: 0.95, 0.98; I² = 22.7%). By comparing the highest category with the lowest category in cohort studies, we discovered that caffeine intake was inversely associated with depressive symptoms (RR: 0.86, 95%CI: 0.79, 0.93; I² = 0.0%, GRADE = moderate). Based on our data analysis, no correlation exists between tea consumption and depressive symptoms.

Conclusion

According to our findings, coffee and dietary caffeine may have a protective effect against the development of depression. However, no evidence suggesting a link between tea consumption and reduced depressive symptoms has been found. Therefore, further longitudinal studies are needed to substantiate the causal relationship between coffee, tea, and caffeine and the risk of depression.

Green tea consumption and risk of depressive symptoms: Results from the TCLSIH Cohort Study

BACKGROUND

The prospective studies on the effect of particular type of tea consumption, especially green tea, on depressive symptoms are limited.

OBJECTIVE

The aim of this study is to investigate the prospective association between green tea consumption and depressive symptoms in a large general adult population.

METHODS

This prospective cohort study investigated 7524 participants aged 25 to 90 years from May 2013 to December 2018 and they were free of cardiovascular disease, cancer, and depressive symptoms at baseline. Green tea consumption was obtained through a validated food frequency questionnaire. Depressive symptoms were assessed by using the Self-Rating Depressive Scale (SDS). The association between green tea consumption and depressive symptoms was analyzed by Cox proportional hazards regression models.

RESULTS

A total of 1064 first incident cases of depressive symptoms (SDS ≥45) occurred during 14,661 person-years of follow-up (median follow-up of 2.0 years). In the crude model, the hazard ratios (95% confidence intervals) were 1.00 (reference), 0.95 (0.81, 1.12), 0.97 (0.83, 1.14) and 0.95 (0.79, 1.14), respectively. After adjusting for demographic characteristics, lifestyle factors, and dietary intake, the multivariable adjusted hazard ratios (95% confidence intervals) were 1.00 (reference), 0.88 (0.74, 1.05), 0.84 (0.69, 1.02) and 0.78 (0.63, 0.97), respectively.

CONCLUSIONS

The prospective study suggests that frequent green tea consumption is associated with a decreased risk of depressive symptoms in the general Chinese population.

Green Tea Consumption and Depressive Symptoms among Japanese Workers: The Furukawa Nutrition and Health Study

Although several cross-sectional studies have described an inverse association between green tea consumption and depressive symptoms, only one study has prospectively investigated this association. We investigated the cross-sectional and prospective associations between green tea consumption and depressive symptoms in a working population in Japan. Participants were 1987 workers who participated in the baseline survey for a cross-sectional association, and 916 participants who did not have depressive symptoms at baseline who responded to both the baseline and follow-up surveys for a prospective association. Green tea consumption was evaluated with a validated self-administered diet history questionnaire. Depression symptoms were evaluated with the Center for Epidemiologic Studies Depression (CES-D) scale. Multiple logistic regression was conducted to estimate the odds ratio of depressive symptoms based on green tea consumption. In the cross-sectional analysis, green tea consumption was not associated with the prevalence of depression symptoms. Moreover, consumption at baseline was not associated with depression symptoms after 3 years; the multivariable-adjusted odds ratio of depressive symptoms for ≥2 cups/day of green tea was 1.12 (95% confidence interval 0.65–1.91) compared with <4 cups/week after adjustment for covariates including dietary factors (trend p = 0.67). Our results suggest that there is no association of consumption of green tea with symptoms of depression in Japanese.

Prevalence of depressive symptoms among older adults in mainland China: A systematic review and meta-analysis

BACKGROUND

To date, the reported prevalence of late-life depression in China has varied considerably, and the pooled overall prevalence of depressive symptoms among older adults in China and the tendency of the rate to change in the past 30 years have remained unknown. Thus, our study was designed to form an accurate and comprehensive picture of the recent prevalence of depressive symptoms among older adults in China.

METHODS

Literature searches were conducted independently by two investigators in English- and Chinese-language databases from database inception to January 2020. The prevalence of depressive symptoms was analysed with a random effects model.

RESULTS

In the 81 eligible studies (n = 261,697) identified, the pooled overall prevalence of depressive symptoms among older adults in China was 20.0% (95% CI, 17.5%-22.8%), with high heterogeneity, Q = 22,947.0, I² = 99.7%, p < .001. Subgroup analyses revealed significant differences in the prevalence of late-life depression depending upon gender, marital status, socio-economic status, and measurement scale(s) used. Meta-regression indicated that the prevalence of depressive symptoms among older adults in China increased from the 1990s to the 2000s but slightly decreased from the 2000s to the 2010s.

LIMITATIONS

Significant heterogeneity among the studies reviewed was unavoidable, and the findings was not generalisable to all regions in China.

CONCLUSIONS

Depressive symptoms are common among older adults in China, and policies should be developed that consider vulnerable older adults in particular.

Type of tea consumption and depressive symptoms in Chinese older adults

Background

Existing research indicates that tea drinking may exert beneficiary effects on mental health. However, associations between different types of tea intake and mental health such as depression have not been fully examined. The purpose of this study was to examine the associations of green tea, fermented tea, and floral tea consumption with depressive symptoms.

Methods

We used data from the 2018 wave of the Chinese Longitudinal Healthy Longevity Survey, a nationwide survey on older adults in mainland China. A total of 13,115 participants (mean age 83.7 years, 54.2% were women) with valid responses were included in the analysis. The type (green, fermented [black, Oolong, white, yellow, dark, and compressed teas], and floral) and the frequency of tea consumption were recorded, and depressive symptoms were assessed using 10-item of the Center for Epidemiologic Studies Depression Scale (CES-D-10). We examined the associations between the type and the frequency of tea intake and depression, controlling for a set of demographic, socioeconomic, psychosocial, behavioral, and health-related variables.

Results

Overall, intakes of green tea, fermented tea, and floral tea were all significantly associated with lower prevalence of depressive symptoms, independent of other risk factors. Compared with the group of no tea intake, the adjusted ORs of depressive symptoms for daily green tea, fermented tea, and floral tea intake were 0.85 (95% CI: 0.76–0.95), 0.87 (95% CI: 0.76–0.99), and 0.70 (95% CI: 0.59–0.82), respectively. Linear associations were observed between the frequencies of all three types of tea intake and depressive symptoms (P < 0.05 for trends for all three types). The associations of the type and the frequency of tea intake and depressive symptoms were robust in several sensitivity analyses.

Conclusions

Among Chinese older adults, regularly consumed any type of tea (green, fermented, or floral) were less likely to show depressive symptoms, the associations seemed more pronounced among floral tea and green tea drinkers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02203-z.

Tea Consumption and Depression from Follow Up in the Singapore Longitudinal Ageing Study

OBJECTIVES

Experimental evidence suggest that tea polyphenols have anti-depressant effect and tea consumption may reduce the risk and severity of depression. We investigated whether tea consumption was associated with changes in depressive symptoms over time among Asian older adults.

DESIGN

Population-based prospective cohort study with mean 4 years of follow up.

SETTING

Singapore Longitudinal Ageing Study (SLAS) of community-living older persons.

PARTICIPANTS

3177 participants overall (mean age 67 years) and 3004 participants who were depression-free at baseline.

MEASUREMENTS

Baseline tea consumption which include Chinese (black, oolong or green) tea or Western (mixed with milk) tea and change in Geriatric Depression Scale (GDS) measure of depression. Incident depression was defined by GDS≥5, and GDS depression improvement or deterioration by GDS change of ≥4 points. Estimated odds ratio and 95% confidence intervals (OR, 95%CI) were adjusted for baseline age, sex, ethnicity, education, housing type, single/divorced/widowed, living alone, physical and social activity, smoking, alcohol, number of comorbidities, MMSE, and baseline GDS level.

RESULTS

Compared to non-tea drinkers, participants who consumed ≥3 cups of tea of all kinds were significantly less likely to have worsened GDS symptoms: OR=0.32, 95% CI=0.12, 0.84. Among baseline depression-free participants, the risk of incident GDS (≥5) depression was significantly lower (OR=0.34, 95%CI=0.13, 0.90) for daily consumption of all types of tea, and Chinese (black, oolong or green) tea (OR=0.46, 95%CI=0.21,0.99).

CONCLUSION

This study suggests that tea may prevent the worsening of existing depressive symptoms and the reduce the likelihood of developing threshold depression.

Effects of Polyphenols in a Mediterranean Diet on Symptoms of Depression: A Systematic Literature Review

Depression is a mood disorder which currently affects 350 million individuals worldwide. Recently, research has suggested a protective role of diet for depression. The Mediterranean-style dietary pattern has been highlighted in several systematic reviews as a promising candidate for reducing depressive symptoms. It has been speculated that this could be due to the high polyphenol content of foods commonly found in the diet. Therefore, the aim of this review was to assess the effects of polyphenols found in a Mediterranean diet on the symptoms of depression. A systematic literature review was conducted of original research which assessed the role of polyphenols on the symptoms of depression in humans. The following databases were searched: PROQUEST, SCOPUS (Elsevier), MEDLINE (EBSCO), CINAHL, and EMBase, up to 18 February, 2019. The inclusion criteria consisted of both observational and experimental research in adults aged 18-80 y that assessed depression scores in relation to polyphenol intake. A total of 37 studies out of 12,084 met the full inclusion criteria. Of these, 17 were experimental studies and 20 were observational studies. Several different polyphenols were assessed including those from tea, coffee, citrus, nuts, soy, grapes, legumes, and spices. Twenty-nine of the studies found a statistically significant effect of polyphenols for depression. This review has found both an association between polyphenol consumption and depression risk, as well as evidence suggesting polyphenols can effectively alleviate depressive symptoms. The review uncovered gaps in the literature regarding the role of polyphenols for depressive symptoms in both young adults and men. This review was registered at www.crd.york.ac.uk/PROSPERO as CRD42019125747.

Association between tea consumption and depressive symptom among Chinese older adults

Background

Despite accumulating evidence on the protective effect of tea consumption against depression, studies specifically focusing on the elderly population are yet limited. This paper examined the association between the frequency and duration of tea drinking and depressive symptoms of older adults by gender and age groups, based on a nationally representative sample in China.

Method

The study employed the panel data from 2005, 2008/2009, 2011/2012 and 2014 waves of Chinese Longitudinal Healthy Longevity Survey (CLHLS). We used the frequency and consistency of tea drinking behaviors to identify four types of tea consumption amongst Chinese seniors. Depressive symptoms were assessed by a five-item scale. Linear mixed effects models were applied.

Results

We found that consistent and frequent tea-drinking was associated with significantly less depressive symptoms, and such impact was partially mediated by socioeconomic status, health behavior, physical health, cognitive function, and social engagement. However, the association was only significant for males and the oldest-old, rather than females and younger elders.

Conclusions

Consistent and frequent tea-drinking may effectively reduce the risk of depressive symptoms for the Chinese elderly. The promotion of the traditional lifestyle of tea drinking could be a cost-effective way towards healthy aging for China.

Electronic supplementary material

The online version of this article (10.1186/s12877-019-1259-z) contains supplementary material, which is available to authorized users.

Analysis of Genetic Diversity and Development of a SCAR Marker for Green Tea (Camellia sinensis) Cultivars in Zhejiang Province: The Most Famous Green Tea-Producing Area in China

Camellia sinensis (L.) O. Kuntze is one of the most important non-alcoholic beverage crops in Asian and African countries. In recent years, many green tea cultivars have been released and played an important role in improving the production and quality of tea trees. The objectives of this study were to assess the genetic diversity of the eighteen main green tea cultivars in Zhejiang Province-the most famous green tea-producing area of China-using start codon-targeted (SCoT) markers and to develop a specific sequence-characterized amplified region (SCAR) marker for application in cultivar diagnosis. Thirty-one SCoT primers produced 264 loci, 226 of which were polymorphic. The genetic similarity coefficients among these green tea cultivars ranged from 0.587 to 0.814, indicating that a high level of genetic diversity was present. Both a UPGMA dendrogram and a PCoA plot grouped the tea cultivars into three groups. The partitioning of groups in the UPGMA and PCoA was similar, and much of the clustering was highly consistent with the classification of tea cultivars according to their genetic backgrounds. A unique SCoT band, SCoT4-1649, specific to the tea cultivar 'Yingshuang,' was transformed into a SCAR marker. This SCAR marker is highly useful for the identification and germplasm conservation of green tea cultivars.

Black tea increases hypertonic stress resistance in C. elegans

Here we identified that BTE (black tea extract), within the studied concentration range, is more effective than GTE (green tea extract) in protecting C. elegans against hypertonic stress, by enhancing survival after exposure to various salts, and alleviating suffered motility loss and body shrinkage. The mechanism of such protection may be due to the ability of black tea to induce the conserved WNK/GCK signaling pathway and down-regulation of the expression levels of nlp-29. Intriguingly, black tea does not relieve hypertonicity-induced protein damage. The findings implicate the potential health benefits of black tea consumed worldwide.

Blood Pressure Is Associated with Tea Consumption: A Cross-sectional Study in a Rural, Elderly Population of Jiangsu China

OBJECTIVES

Tea has long been hypothesized to possess hypotensive effects. However, there is uncertainty regarding the association of tea consumption with arterial blood pressure (BP). We aimed to examine the association between tea consumption and BP components including systolic BP (SBP) and diastolic BP (DBP).

DESIGN

Community-based, cross-sectional study of Suzhou City, Jiangsu Province, China.

SETTING

Tea consumption has protective influence on BP and presence of hypertension.

PARTICIPANTS

4579 older adults aged 60 years or older from the Weitang Geriatric Diseases study.

MEASUREMENTS

Detailed information regarding tea consumption was collected using a pre-designed questionnaire. BP components were measured at least 3 times with a minimum 5-minute interval, by well-trained research nurses.

METHODS

Data of 4579 older adults (response rate: 82%) aged 60 years or older from the Weitang Geriatric Diseases study were included in the analysis and we estimated the relationship of tea consumption and BP using linear regression models and the association between tea consumption and risk of hypertension using logistic regression models.

RESULTS

In linear regression models, higher tea consumption frequency was found to be associated with lower systolic BP values, after adjusting for the effect of age, sex, education level, lifestyle-related factors, and cardiometabolic confounding factors in overall (coefficient =-1.49, P=0.0003), normotensive (coefficient =-0.91, P=0.017) and participants without anti-hypertensive treatment (coefficient =-1.26, P=0.027). Significant inverse association between diastolic BP and frequency of tea consumption was also observed in the overall subjects (coefficient =-0.74, P=0.003). In multivariate logistic analyses, habitual tea drinking was inversely associated with presence of hypertension [odds ratio (OR)=0.79, P=0.011] , and there was a progressive reduction in risk associated with higher frequency of tea consumption (P for trend=0.011).

CONCLUSION

Habitual tea consumption was found to be associated with lower values of components of BP and a reduced likelihood of having hypertension in older adults. Given the widespread consumption of tea throughout China and the world, together with the major cardiovascular disease risk, our findings have important implications for human health.