Lack of a causal relationship between tea intake and sleep disorders: a two-sample Mendelian randomization study

Background:The relationship between tea intake(TI)and sleep disorders(SDs)has been a topic of interest for some time,but there remains a lack of data showing a causal relationship.We aimed to use a two-sample Mendelian randomization study to determine whether there is a causal link between TI and SDs.Methods:We collected data regarding TI,with a focus on green tea intake(GTI),herbal tea intake(HTI),and rooibos tea intake(RTI);and data regarding SDs and insomnia from genome-wide association studies.We analyzed these data using an inverse variance-weighted two-sample Mendelian randomization study,by means of the TwoSampleMR package in R4.2.3 software.Results:We found no genetic causal relationships of TI,GTI,HTI,or RTI with insomnia.The odds ratios(ORs)for these relationships were as follows:TI:OR=0.61,95%confidence interval(CI):0.29–1.28;GTI:OR=1.04,95%CI:0.95–1.14;HTI:OR=0.98,95%CI:0.82–1.17;and RTI:OR=1.04,95%CI:0.99–1.09.In addition,there were no genetic causal relationships of TI,GTI,HTI,or RTI with SDs.The OR values for these relationships were as follows:TI:OR=0.6,95%CI:0.34–1.06;GTI:OR=1,95%CI:0.93–1.07;HTI:OR=0.89,95%CI:0.66–1.2;and RTI:OR=1.02,95%CI:0.98–1.06.Conclusion:We found no causal relationships of TI with SDs or insomnia,irrespective of the type of tea consumed.However,additional Mendelian randomization studies are required to further explore the relationships of the timing and quantity of tea consumption with SDs and insomnia.

Genetic causal relationship between tea intake and cerebral aneurysm: a two-sample Mendelian Randomization Study

Background:Prior research has established a strong link between cerebral aneurysm(CA)occurrence and inflammation.Tea intake(TI)has been found to have anti-inflammatory properties through multiple mechanisms,potentially lowering CA incidence.This study aims to employ Mendelian Randomization(MR)methodology to explore the genetic causality between TI and CA.Methods:We collected Genome-wide association study(GWAS)data for CA,TI,Green tea intake(GTI),Herbal tea intake(HTI),and Rooibos tea intake(RTI).The MR analysis employed the TwoSampleMR package and utilized the inverse variance-weighted(IVW)method.Results:The findings suggest no genetic causal relationship between TI and CA(IVW:OR=1.10,95%CI:0.59–2.05,P=0.772).Similarly,there is no genetic causal association between GTI and CA(IVW:OR=1.07,95%CI:0.91–1.26,P=0.388),HTI and CA(IVW:OR=1.00,95%CI:0.89–1.13,P=0.943),or RTI and CA(IVW:OR=1.02,95%CI:0.96–1.09,P=0.472).Conclusion:There is no genetic causal relationship between TI and CA,and the different types of tea do not change this result.Further MR analysis is needed to investigate whether there is a potential genetic causal association between the quantity of TI and CA.

No genetic causal relationship between tea intake and diabetes:a two-sample Mendelian randomization study

Background:Previous studies have suggested a potential risk-reducing effect of tea intake(TI)on diabetes.However,the specific impacts of TI on different types of diabetes and its underlying mechanisms remain unclear.To further explore this topic,we conducted a comprehensive investigation to assess the causal relationship between TI and various types of diabetes,as well as its effects on blood glucose(Glu)and glycated hemoglobin(HbA1).Methods:We collected genome-wide association study data for TI,diabetes,type 1 diabetes(T1D),type 2 diabetes(T2D),Glu,HbA1,green tea intake,herbal tea intake,and Rooibos tea intake from the IEU database.Subsequently,we performed two-sample Mendelian randomization analysis using the TwoSampleMR package.Results:Our analysis revealed no evidence of a causal relationship between TI and the incidence of diabetes,T1D,blood Glu,HbA1c,or T2D.Similarly,no genetic causal relationship was found between green tea intake and diabetes,T1D,T2D,Glu,or HbA1c.The same applied to herbal tea intake and Rooibos tea intake,as there was no genetic causal link with diabetes,T1D,T2D,Glu,or HbA1c.Conclusion:Based on our findings,there is no indication of a causal relationship between TI and the incidence of all types of diabetes,regardless of the specific tea type.However,to comprehensively understand the potential effects of TI on diabetes incidence,including the quantity and timing of intake,further evaluation through additional Mendelian randomization studies is warranted.