New research unveils a beverage lauded for its established benefits in managing abrupt blood pressure increases. However, caution is urged as when combined with alcohol, its health impacts could intensify, potentially leading to more adverse effects.
Tea is a widely popular beverage enjoyed by people all over the world. Numerous studies have emerged in recent times highlighting the positive impact of tea consumption on various health conditions, such as hypertension, cardiovascular disorders, diabetes, stroke, heart attack, and mortality.
Nonetheless, there are several factors that can potentially diminish the health advantages associated with tea consumption. These factors include the presence of milk, smoking habits, coffee consumption, lifestyle choices, and gender.
It is important to note that there is limited data available regarding the potential interactions between alcohol and tea, particularly in relation to outcomes such as hypertension and mortality.
In a newly published study featured in the Nutrition Journal, a team of researchers delved into the potential correlation between tea consumption and its protective effects against hypertension and mortality among Chinese individuals. The study aimed to determine whether this protective relationship would be influenced by alcohol intake.
In this extensive and forward-looking cohort study, researchers aimed to explore the relationship between tea consumption, changes in blood pressure (BP), and mortality among individuals who consume alcohol compared to those who do not, in China.
The study encompassed a total of 6,387 participants from the China Health and Nutrition Survey (CHNS), spanning the period from 1993 to 2011.
For the analysis in question, individuals who had at least two records of tea consumption, with a minimum of one record from 1993, were included. The researchers employed a technique called group-based trajectory modeling (GBTM) to identify distinct long-term patterns of tea consumption over the course of 18 years.
Information on tea intake during the preceding year, including the average number of cups consumed daily, was gathered through in-person surveys conducted in various follow-up rounds between 1993 and 2011. Participants who reported consuming alcohol during the previous year were categorized as current alcohol consumers. The outcomes examined in the study were mortality from any cause and changes in blood pressure readings.
To gather information on mortality, interviews were conducted with family members of deceased individuals. The duration of follow-up was determined by recording either the last day of life or the date of the final survey, whichever occurred earlier.
To assess the cumulative mortality rate, the research team employed Cox regression modeling and Kaplan-Meier statistics. They also used restricted cubic splines to examine potential non-linear associations between the average consumption of tea and the risk of death.
The effects of different trajectories of tea intake on blood pressure were evaluated using generalized linear mixed-effects modeling (GLMM). Additionally, the hazard ratio (HR) was calculated, taking into account various covariates such as age, marital status, sex, nationality, residence, level of education, occupation, annual household income, smoking habits, comorbidities (such as diabetes, hypertension, and cancer), use of antihypertensive medication, and mean values for body mass index (BMI), waist circumference, and hip circumference
Data from the China Health and Nutrition Survey (CHNS) was collected from 12.0 provinces using a multistage, random-cluster sampling method. The CHNS study began in 1989 and involved periodic follow-ups every two to four years until 2015, encompassing over 30,000 individuals.
The average age of the participants was 54 years, with a gender distribution of 50% male. Approximately 33% of the individuals reported consuming alcohol at the time of the study.
The study population was categorized into three groups based on their tea consumption habits: non-tea consumers (no cups consumed daily), light tea consumers (one cup per day), and high tea consumers (three to four cups per day). Among the study participants, 2,838 fell into the light tea consumption group, while 1,478 were categorized as high tea consumers.
Following a median follow-up period of 18 years, nine percent of the participants (n=580) passed away. The analysis revealed that the relationship between tea intake and mortality was influenced by alcohol consumption.
The mortality rate among individuals who consume high amounts of tea was found to be lower compared to non-tea consumers (HR 0.8). However, this reduced mortality risk associated with high tea intake was observed only among those who do not consume alcohol (HR 0.6).
The relationship between tea consumption and mortality among current alcohol consumers followed a linear pattern, indicating that the benefits of tea against mortality were overshadowed by the presence of alcohol. Furthermore, the results from the GLMM modeling revealed that alcohol also masked the blood pressure-lowering effects of tea. These findings were consistent when analyzing the data separately for males and females.
Individuals who consumed high amounts of tea on a daily basis were more likely to be older males who smoked and resided in urban areas.
Current alcohol consumers had a higher likelihood of engaging in unhealthy lifestyles, such as smoking, and exhibited higher values for BMI, waist circumference, and hip circumference compared to non-alcohol drinkers. These factors could potentially diminish the positive effects of tea consumption.
According to the study, the presence of alcohol in the body diminishes the beneficial effects of tea-derived polyphenols, which are known for their antioxidant properties. Additionally, it has been observed that drinking tea can contribute to a delay in arterial stiffness, which may be responsible for its positive impact on reducing blood pressure.
The study overall revealed that individuals who consumed three to four cups of regular tea had a lower risk of mortality and were able to prevent increases in blood pressure. However, it was found that the consumption of alcohol reduced the benefits of tea and, in some cases, even posed risks to health.
These findings support and expand on previous studies that have reported the positive effects of tea consumption on mortality rates, particularly in the Chinese population. It is important to note, however, that the sample used in this study does not fully represent the entire nation, and therefore, the generalizability of the findings is limited.
To further explore this topic, according to the authors, future research should focus on analyzing national data obtained from randomized controlled trials (RCTs) that investigate tea consumption, including the specific types of tea consumed, utilizing objective assessment methods. This will provide a more comprehensive understanding of the relationship between tea intake and its health benefits.
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