Drinking more water may lower heart disease risk, but too much coffee and tea could raise it

A new study finds that high coffee and tea consumption is linked to increased heart disease risk, while drinking more water could offer protection—especially for women.

​​​​​​​Study: Sex differences in the associations of water, coffee and tea consumption with cardiovascular diseases: a prospective cohort study. ​​​​​​​Image Credit: Viktoriya Krayn / Shutterstock

In a recent study published in the journal Frontiers in Nutrition, researchers investigated the associations between water, tea, and coffee intake and subsequent cardiovascular disease (CVD). They further evaluated potential sex differences in these associations using the United Kingdom (UK) Biobank data. Their long-term dataset comprised more than 461,000 participants, followed over a median of 8.7 years.

Study findings revealed that water consumption had a protective effect against CVD risk, with participants reporting higher consumption, which generally depicted lower CVD incidence. In contrast, high coffee and tea consumption (≥6 cups/day) was associated with a higher likelihood of future CVD. The negative associations between excessive coffee/tea consumption and CVD risk were stronger in women than in men. Notably, coffee and tea consumption partially attenuated the benefits of water consumption rather than fully negating them, particularly in participants consuming higher quantities of both water and tea or coffee.

Background

Cardiovascular diseases (CVDs) are an umbrella term for several conditions that adversely impact the heart, circulatory system, or blood vessels. They include coronary heart disease (CHD), heart failure (HF), hypertension, and strokes—together comprising the leading non-transmissible cause of human mortality worldwide. The United States (US) Centers for Disease Control and Prevention (CDC) National Health and Nutrition Examination Study (NHANES) 2017–2020 report estimated that 48.6% of all adults live with CVDs, an alarming progressive growth from previous years.

Research from 2020 estimated 19.05 million human deaths attributable to CVDs, a substantial 18.71% jump from just a decade prior, highlighting the need for research and public health initiatives against these deadly medical conditions. Several factors have been identified as contributing to CVD risk, including genetics, behaviors (diet, sleep, physical exercise, and smoking/alcohol status), and, most recently, sex.

“Compared to men, women possess an additional X chromosome, which may result in variations in gene expression and functional outcomes within the cardiovascular system. Literature data suggest that women experience a two-fold incidence of CVD-related mortality compared to men, indicating that biological sex is a critical determinant in disease severity and resultant heterogeneity.”

While the independent contributions of water and other popular beverages (coffee and tea) to CVD risk have previously been established, their combined associations remain less well understood.

About the Study

The present study aims to address these knowledge gaps by evaluating potential sexual dimorphism in male and female responses to the spectrum of water, tea, and coffee consumption. Study data was obtained from the United Kingdom (UK) Biobank and initially comprised more than 500,000 adults (>40 years) across Wales, England, and Scotland. Participants with previous CVD incidents, incomplete medical data, or inconclusive ages were excluded from the analysis, resulting in a final dataset of 251,383 women and 210,239 men (totaling 461,622 participants).

The ACE touchscreen questionnaire was used to record participant dietary data, specifically the daily frequency and amount of water, coffee, and tea consumption. This data was aggregated into a composite variable for analytical modeling. Participants who recorded “prefer not to say” were excluded from downstream analysis.

UK Biobank medical datasets, including hospital admission data, death registry entries, and primary care repositories, were queried for CVD incidence assessments. Assessment models were adjusted for covariates, including ethnicity, smoking status, alcohol consumption, education, sex, diet (healthy or unhealthy), and age.

Cox proportional hazard regression models were used to investigate the associations between participant data (beverage consumption) and CVD outcomes. Finally, sensitivity analyses were carried out to ensure the robustness of the study findings.

Study Findings

Of the 461,622 participants in the final dataset, HF manifested in 11,098 (2.4%), CHD in 33,426 (7.24%), and stroke in 9,706 (2.1%) of participants. Water consumption evaluations revealed that the liquid has a protective effect against CVD incidence, with higher water consumption (≥6 cups/day) associated with lower CVD hazard ratios (HRs) in both men (HR = 0.87) and women (HR = 0.96). Similar findings were noted for CHD (HR = 0.81 for men and 0.80 for women) and strokes (HR = 0.79 for men and 0.81 for women).

Notably, in almost all cases, women exhibited a higher risk for CVD incidence than their male counterparts. However, the strongest sex-specific differences were found in the associations between coffee/tea intake and CHD risk rather than for all CVD types.

High coffee and tea consumption (≥6 cups/day) was associated with an increased CVD risk of 12–23%. Once again, women showed stronger associations with CVD risk than their male counterparts.

Notably, very high (>8 cups per day) intake of either coffee, tea, or both increased CHD event probability by 48% for men and 49% for women, confirming their adverse cardiovascular effects.

​​​​​​​Associations of composite coffee and tea intake with cardiovascular diseases in different water consumption groups. The multivariable model was adjusted for baseline age, ethnicity, education, income, smoking status, physical activity, diet pattern, body mass index, systolic blood pressure, diastolic blood pressure, triglycerides, high-density lipoprotein, low-density lipoprotein, long-standing illness, disability or infirmity, Townsend Deprivation Index, alcohol consumption and milk consumption.

Conclusions

The present study investigated the effects of water, tea, and coffee consumption on CVD outcomes in an extensive (n = 461,622) long-term (median follow-up duration = 8.7 years) UK Biobank cohort to elucidate potential sexual dimorphism in their impacts on cardiovascular health. Study findings revealed that water had a protective effect against CVD risk, while high coffee and tea intake (≥6 cups/day) was linked to increased CVD incidence in participants who consumed higher daily amounts of either beverage.

Women were impacted more than men across all investigations, confirming their increased susceptibility to CVD events —with the strongest sex-based differences observed in CHD risk.

“…we found that high coffee and tea consumption was associated with an increased risk of cardiovascular diseases in both sexes (especially when they consume ≥6 cups/day); daily water consumption was associated with a lower risk of cardiovascular diseases in both men and women. Our research indicates the significance of moderate fluid consumption in daily life.”