Tea Consumption and Health Outcomes: Umbrella Review of Meta‐Analyses of Observational Studies in Humans

ABSTRACT Numerous observational studies have investigated the role of the Dietary Inflammatory Index (DII®) in chronic disease risk. The aims of this umbrella review and integrated meta-analyses were to systematically synthesize the observational evidence reporting on the associations between the DII and health outcomes based on meta-analyses, and to assess the quality and strength of the evidence for each associated outcome. This umbrella review with integrated meta-analyses investigated the association between the DII and a range of health outcomes based on meta-analyses of observational data. A credibility assessment was conducted for each outcome using the following criteria: statistical heterogeneity, 95% prediction intervals, evidence for small-study effect and/or excess significance bias, as well as effect sizes and P values using calculated random effects meta-analyses. In total, 15 meta-analyses reporting on 38 chronic disease-related outcomes were included, incorporating a total population of 4,360,111 subjects. Outcomes (n = 38) were examined through various study designs including case-control (n = 8), cross-sectional (n = 5), prospective (n = 5), and combination (n = 20) study designs. Adherence to a pro-inflammatory dietary pattern had a significant positive association with 27 (71%) of the included health outcomes (P value < 0.05). Using the credibility assessment, Class I (Convincing) evidence was identified for myocardial infarction only, Class II (Highly suggestive) evidence was identified for increased risk of all-cause mortality, overall risk of incident cancer, and risk of incident site-specific cancers (colorectal, pancreatic, respiratory, and oral cancers) with increasing (more pro-inflammatory) DII score. Most outcomes (n = 31) presented Class III (Suggestive) or lower evidence (Weak or No association). Pro-inflammatory dietary patterns were nominally associated with an increased risk of many chronic disease outcomes. However, the strength of evidence for most outcomes was limited. Further prospective studies are required to improve the precision of the effect size.

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Dietary Inflammatory Index and Health Outcomes: An Umbrella Review of Systematic Review and Meta-Analyses of Observational Studies

Frontiers in Nutrition ◽

10.3389/fnut.2021.647122 ◽

2021 ◽

Vol 8 ◽

Author(s):

Fang-Hua Liu ◽

Chuan Liu ◽

Ting-Ting Gong ◽

Song Gao ◽

Hui Sun ◽

...

Keyword(s):

Prostate Cancer ◽

Colorectal Cancer ◽

Health Outcomes ◽

Observational Studies ◽

Cancer Colorectal ◽

Dietary Inflammatory Index ◽

Umbrella Review ◽

Inflammatory Index ◽

Cancer Breast ◽

Meta Analyses

Background and Aims: The dietary inflammatory index (DII) is associated with non-communicable disease. We conducted an umbrella review to systematically evaluate meta-analyses of observational studies on DII and diverse health outcomes.Methods: We comprehensively searched the PubMed, Web of Science, and Embase databases to identify related systematic reviews and meta-analyses of observational studies. Those investigating the association between DII and a wide range of health outcomes in humans were eligible for inclusion. For each meta-analysis, we estimated the summary effect size by using fixed and random effects models, the 95% confidence interval, and the 95% prediction interval. We assessed heterogeneity, evidence of small-study effects, and excess significance bias.Results: The umbrella review identified 35 meta-analyses assessing associations between DII and various health outcomes: cancer (n = 24), mortality (n = 4), metabolic (n = 4), and other (n = 3). The methodological quality was high or moderate. Of the 35 meta-analyses, we observed highly suggestive evidence for harmful associations between digestive tract cancer, colorectal cancer, overall cancer, pharyngeal cancer, UADT cancer, and CVD mortality. Moreover, 11 harmful associations showed suggestive evidence: hormone-dependent cancer, rectal cancer, colon cancer, breast and prostate cancer, gynecological cancer, breast cancer, ovarian cancer, colorectal cancer, prostate cancer, all-cause mortality, and depression.Conclusion: DII is likely to be associated with harmful effects in multiple health outcomes. Robust randomized controlled trials are warranted to understand whether the observed results are causal.Systematic Review Registration: CRD42021218361

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Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational studies and randomised trials

BMJ ◽

10.1136/bmj.g2035 ◽

2014 ◽

Vol 348 (apr01 2) ◽

pp. g2035-g2035 ◽

Cited By ~ 463

Author(s):

E. Theodoratou ◽

I. Tzoulaki ◽

L. Zgaga ◽

J. P. A. Ioannidis

Keyword(s):

Vitamin D ◽

Health Outcomes ◽

Systematic Reviews ◽

Observational Studies ◽

Randomised Trials ◽

Umbrella Review ◽

Meta Analyses ◽

Multiple Health

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Dietary Carbohydrate and Diverse Health Outcomes: Umbrella Review of 30 Systematic Reviews and Meta-Analyses of 281 Observational Studies

Frontiers in Nutrition ◽

10.3389/fnut.2021.670411 ◽

2021 ◽

Vol 8 ◽

Author(s):

Ya-Shu Liu ◽

Qi-Jun Wu ◽

Jia-Le Lv ◽

Yu-Ting Jiang ◽

Hui Sun ◽

...

Keyword(s):

Metabolic Syndrome ◽

Health Outcomes ◽

Systematic Reviews ◽

Observational Studies ◽

Carbohydrate Intake ◽

Dietary Carbohydrate ◽

Umbrella Review ◽

Suggestive Evidence ◽

All Cause Mortality ◽

Meta Analyses

Background and Aims: The associations between dietary carbohydrate and diverse health outcomes remain controversial and confusing. To summarize the existing evidence of the association between dietary carbohydrate intake and diverse health outcomes and to evaluate the credibility of these sources of evidence. We performed this umbrella review of evidence from meta-analyses of observational studies.Methods: PubMed, Embase, Web of Science databases, and manual screening of references up to July 2020 were searched. Systematic reviews with meta-analyses of observational studies in humans investigating the association between dietary carbohydrate intake and multiple health outcomes were identified. We assessed the evidence levels by using summary effect sizes, 95% prediction intervals, between-study heterogeneity, evidence of small-study effects, and evidence of excess significance bias for each meta-analysis.Results: We included 43 meta-analyses of observational research studies with 23 health outcomes, including cancer (n = 26), mortality (n = 4), metabolic diseases (n = 4), digestive system outcomes (n = 3), and other outcomes [coronary heart disease (n = 2), stroke (n = 1), Parkinson's disease (n = 1), and bone fracture (n = 2)]. This umbrella review summarized 281 individual studies with 13,164,365 participants. Highly suggestive evidence of an association between dietary carbohydrate intake and metabolic syndrome was observed with adjusted summary odds ratio of 1.25 [95% confidence interval (CI) 1.15–1.37]. The suggestive evidences were observed in associations of carbohydrate consumption with esophageal adenocarcinoma (0.57, 95% CI = 0.42–0.78) and all-cause mortality (adjusted summary hazard ratio 1.19, 95% CI = 1.09–1.30).Conclusions: Despite the fact that numerous systematic reviews and meta-analyses have explored the relationship between carbohydrate intake and diverse health outcomes, there is no convincing evidence of a clear role of carbohydrate intake. However, there is highly suggestive evidence suggested carbohydrate intake is associated with high risk of metabolic syndrome, suggestive evidence found its association with increased risk of all-cause mortality and decreased risk of esophageal adenocarcinoma.Systematic Review Registration: CRD42020197424.

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Human Immunodeficiency Virus Infection and Diverse Physical Health Outcomes: An Umbrella Review of Meta-analyses of Observational Studies

Clinical Infectious Diseases ◽

10.1093/cid/ciz539 ◽

2019 ◽

Vol 70 (9) ◽

pp. 1809-1815 ◽

Cited By ~ 4

Author(s):

Igor Grabovac ◽

Nicola Veronese ◽

Sinisa Stefanac ◽

Sandra Haider ◽

Sarah E Jackson ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Health Outcomes ◽

Observational Studies ◽

Umbrella Review ◽

Physical Health Outcomes ◽

Suggestive Evidence ◽

Immunodeficiency Virus ◽

Maternal Sepsis ◽

Meta Analyses ◽

Related Mortality

Abstract Background Our aim was to assess both the credibility and strength of evidence arising from systematic reviews with meta-analyses of observational studies and physical health outcomes associated with human immunodeficiency virus (HIV) but not acquired immunodeficiency syndrome. Methods We performed an umbrella review of observational studies. Evidence was graded as convincing, highly suggestive, suggestive, weak, or nonsignificant. Results From 3413 studies returned, 20 were included, covering 55 health outcomes. Median number of participants was 18 743 (range 403–225 000 000). Overall, 45 (81.8%) of the 55 unique outcomes reported nominally significant summary results (P < .05). Only 5 outcomes (9.0%; higher likelihood of presence of breathlessness, higher chronic obstructive pulmonary disease [COPD] prevalence, maternal sepsis, higher risk of anemia, and higher risk of all fractures among people living with HIV [PLWHIV]) showed suggestive evidence, with P values < 10–3; only 3 (5.5%; higher prevalence of cough in cross-sectional studies, higher incidence of pregnancy-related mortality, and higher incidence of ischemic heart disease among PLWHIV in cohort studies) outcomes showed stronger evidence using a stringent P value (<10–6). None of the unique outcomes presented convincing evidence (Class I), yet 3 outcomes presented highly suggestive evidence, 5 outcomes presented suggestive evidence, and 37 outcomes presented weak evidence. Conclusions Results show highly suggestive and suggestive evidence for HIV and the presence of a cough, COPD, ischemic heart disease, pregnancy-related mortality, maternal sepsis, and bone fractures. Public health policies should reflect and accommodate these changes, especially in light of the increases in the life expectancy and the incidence of comorbidities in this population.

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Ambient PM 2.5 Exposure and Various Health Outcomes: An Umbrella Review of Systematic Reviews and Meta-Analyses of Observational Studies

SSRN Electronic Journal ◽

10.2139/ssrn.3854663 ◽

2021 ◽

Author(s):

Si-Tian Zang ◽

Qi-Jun Wu ◽

Xin-Yu Li ◽

Chang Gao ◽

Ya-Shu Liu ◽

...

Keyword(s):

Health Outcomes ◽

Systematic Reviews ◽

Observational Studies ◽

Umbrella Review ◽

Meta Analyses

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Tea Consumption and Risk of Cancer: An Umbrella Review and Meta-Analysis of Observational Studies

Advances in Nutrition ◽

10.1093/advances/nmaa077 ◽

2020 ◽

Vol 11 (6) ◽

pp. 1437-1452 ◽

Cited By ~ 1

Author(s):

Tai Lim Kim ◽

Gwang Hun Jeong ◽

Jae Won Yang ◽

Keum Hwa Lee ◽

Andreas Kronbichler ◽

...

Keyword(s):

Oral Cancer ◽

Cancer Risk ◽

Biliary Tract ◽

Observational Studies ◽

P Value ◽

Tea Consumption ◽

Umbrella Review ◽

Different Types ◽

Meta Analyses ◽

Risk Of Cancer

ABSTRACT Tea is one of the most widely consumed beverages, but its association with cancer risk remains controversial and unclear. We performed an umbrella review to clarify and determine the associations between tea consumption and various types of cancer by summarizing and recalculating the existing meta-analyses. Meta-analyses of observational studies reporting associations between tea consumption and cancer risk were searched on PubMed and Embase. Associations found to be statistically significant were further classified into levels of evidence (convincing, suggestive, or weak), based on P value, between-study heterogeneity, prediction intervals, and small study effects. Sixty-four observational studies (case-control or cohort) corresponding to 154 effect sizes on the incidence of 25 types of cancer were included. Forty-three (27.9%) results in 15 different types of cancer were statistically significant. When combining all studies on the same type of cancer, 19 results in 11 different types of cancer showed significant associations with lower risk of gastrointestinal tract organ cancer (oral, gastric, colorectal, biliary tract, and liver cancer), breast cancer, and gynecological cancer (endometrial and ovarian cancer) as well as leukemia, lung cancer, and thyroid cancer. Only the reduced risk of oral cancer in tea-consuming populations (OR = 0.62; 95% CI: 0.55, 0.72; P value < 10−6) was supported by convincing evidence. Suggestive evidence was found for 6 results on biliary tract, breast, endometrial, liver, and oral cancer. To summarize, tea consumption was shown to have protective effects on some types of cancer, particularly oral cancer. More well-designed prospective studies are needed with consideration of other factors that can cause biases.

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