A Prospective Cohort Study On The Relationship Between Tea Drinking And Milk Intake And Cardiovascular Disease In Chinese Residents

Cardiovascular disease(CVD) is the leading cause of death and disease burden globally and in China.The increasing trends of CVD incidence and mortality rates have been contained in developed countries in recent years because of the improvement of CVD prevention,diagnosis,and treatment.However,the CVD incidence and mortality rates are still on the rise in China along with the ageing population and changing of lifestyels.In 2017,4.38 million deaths were attributable to CVD,which made up 40%of all deaths in China.Thus,it is important to strengthen and promote primary prevention against CVD burden through lifestyle modification strategies.Lots of previous studies have proved that CVD incidence and mortality are closely related to behavioral risk factors including smoking,lack of physical activity,unhealthy diets.Promoting healthy behaviors and adopting healthy lifestyle are effective in CVD primary prevention.Plan for the Healthy China 2030 pointed out that it is necessary to popularize healthy lifestyle,adopt self-regulated healthy behaviors such as healthy diets,etc.to promote national health and longevity,to make the country prosperous and strong and the nation rejuvenated.Thus,it is crucial to realize the effects of different behavioral factors thoroughly to provide scientific evidence for CVD prevention and to contain the increase of disease burden of CVD.Part ? Tea Consumption and the Risks of Cardiovascular Diseases among Chinese AdultsBackground and Study AimsAs one of the most popular non-achoholic beverage worldwide,tea has a long history and has formed a unique culture in China.It has attacted great attention from both the public and the researchers because of its potential health benefits.The role of tea consumption in the primary.prevention of CVD remains unclear in cohort studies.This prospective cohort study among general Chinese adults aimed to investigate the associations of tea consumption with the risk of CVD and all-cause mortality and to provide more evidence for the prevention of CVD through lifestyle modification.MethodsWe included three sub-cohorts from the project of Prediction for ASCVD Risk in China(China-PAR)including China Multi-Center Collaborative Study of Cardiovascular Epidemiology(China MUCA1998),International Collaborative Study of Cardiovascular Disease in Asia(InterAsia)and Community Intervention of Metabolic Syndrome in China and Chinese Family Health Study(CIMIC).These three cohorts were established in 1998,2000-2001 and 2007-2008,separately.The China MUCA1998 cohort and the InterAsia cohort were followed during 2007-2008 for the first time and all three cohorts were followed during 2012-2015.Baseline survey included questionnaire which collected information on demographic characteristics,family and personal medical history,lifestyle factors,body measure and biochemistry examinations.Tea consumption information was collected using food frequency questionnaire including tea consumption frequeny,tea consumption amount and the type of tea consumed.During follow-up suerveys,participants went through the same questionnaire survey,physical and biochemistry examinitions as the baseline.Outcomes were identified by interviewing study participants or their proxies and,and hospital records and/or death certificates were also checked.All these records were reviewed by the end-point committee.CVD cases included coronary heart disease(CHD),stroke and its ischemic and hemorrhagic subtypes.All death cases were reviewed and identified according to the International Classification of Disease(10th edition,ICD-10).Study participants were categorized as habitual tea consumers(?3 times/week)or non-habitual tea consumers(<3 times/week).Cox proportional hazard regression models were used to calculate hazard ratio(HR)and the corresponding 95%confidential interval(CI)in relation to tea consumption habits.Areas under survival curves of habitual or non-habitual tea consumers were calculated to estimate the difference of disease-free years or gain of life expectancy.Restricted cubic spline(RCS)was applied to explore the dose-response relationships between tea consumption amounts and the risks of CVD incidence and mortality,and all-cause mortality as well.The influence of behavior changes relating to tea consumption was also explored among participants who had tea consumption information at both baseline and the follow-up survey during 2007-2008 from the InterAsia and the China MUCA1998 cohorts.ResultsA total of 100,902 participants were included in the current study.During a median follow-up of 7.3 years,3683 CVD events,1477 CVD deaths,and 5479 all-cause deaths were recorded.Compared with never or non-habitual tea drinkers,the multivariate HR(95%CI)among habitual tea drinkers was 0.91(0.85-0.97),0.82(0.73-0.91)and 0.87(0.81-0.92)for CVD incidence,CVD mortality and all-cause mortality,respectively.Habitual tea drinkers had 1.56 years longer of CVD-free year and 2.17 years longer of life expectancy at the index age of 50 years.Furthermore,consistent habitual tea drinkers during the follow-up period had much lower risks of CVD incidence and all-cause mortality,with the corresponding HR of 0.68(0.53-0.86),0.42(0.26-0.70)and 0.73(0.57-0.92),respectively.ConclusionTea consumption was associated with reduced risks of CVD and all-cause mortality,especially among those consistent habitual tea drinkers.The health benefits of tea consumption were more robust and consistent among men and hatibutal green tea consumers.Part ? Milk Intake and the Risks of Cardiovascular Diseases among Chinese Adults Background and Study AimsDairy products are nutrient-rich and popular diet choice worldwide and are recommended by dietary guidelines in many countries.However,previous studies on the health effects of dairies did not reach any confirm conclusion and there were obvious differences between the results in eastern and western populations.Meta-analyses based on original studies conducted among the western populations did not observe cardiovascular protective effects of dairy products,while studies in Japan or Singapore found that milk might decrease the risk of CVD.In addition,some studies in countries with high consumption levels like Sweden and Denmark reported that milk intake would increase the risk of CVD or all-cause mortality.Milk consumption level among Chinese adults has been low and few epidemiological studies before paid attention to the relationship between milk intake and CVD incidence,CVD mortality or all-cause mortality in China.Thus,the aim of the current study was to explore these relationships using large-scale prospective cohort study and to provide new evidence for the dietary guidelines in China.MethodsWe included three sub-cohorts from the China-PAR including China MUCA1998,InterAsia and CIMIC,which were the same as in the PART I.During the 2007-2008 surveys for these three cohorts,questions about milk consumption were included in the uniformed food frequency questionnaires.Dietary items included milk and yogurt,which were treated equally,and the information on the frequency and amount of milk intake was collected.Participants also attended physical and biochemistry examinations.Outcomes were identified by interviewing study participants or their proxies,and hospital records and/or death certificates were also checked.All these records were reviewed by the end-point committee.CVD cases included CHD,stroke and its ischemic and hemorrhagic subtypes.All records of death cases were reviewed and the causes of death were identified according to ICD-10 codes.According to the Dietary Guidelines for Chinese Residents(2016)and the sizes of commercially available prepackaging milk products,study participants were categorized into four groups:never drank milk,1-150g/d,151-299g/d,?300g/d.Cox proportional hazard regression models were used to calculate HR(95%CI)of CVD incidence,cause-specific mortality and all-cause mortality related to milk intake.RCS analyses were applied to examine dose-response associations.ResultsAmong the 91,757 participants with a median follow-up period of 5.8 years,we documented 3877 CVD cases and 4091 all-cause deaths.Only 24.6%of all study participants reported that they had milk intake habits.Compared with participants who never consumed milk,the multivariate-adjusted HR(95%CI)of CVD incidence for 1-150g/d,151-299g/d and>300g/d was 0.97(0.89-1.07),0.83(0.71-0.97)and 0.68(0.45-1.02),respectively;each 100g increase of daily milk intake was associated with 8%lower risk of CVD incidence(HR,0.92;95%CI:0.87-0.97;P=0.003).Compared with participants who never consumed milk,the multivariate-adjusted HR(95%CI)of CVD mortality for 1-150g/d,151-299g/d and>300g/d was 1.04(0.90-1.21),0.89(0.7-1.14)and 0.63(0.31-1.26),respectively;and the HR(95%CI)associated with each 100g increase of daily milk intake was 0.93(0.86-1.01)(P=0.092).We did not observe statistical significant association between milk intake and all-cause mortality.ConclusionDaily milk intake was associated with lower risk of CVD incidence and mortality in a linear inverse relationship.The findings provide new evidence for dietary recommendations in CVD prevention among Chinese adults and people with similar dietary pattern in other countries.