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Drinking 2 cups of coffee in people with severe hypertension increases the risk of cardiovascular disease death

2023.01.22 23:18:00 Dustin Kim

[Picture of a cup of coffee, photo credit to Pixaby]

According to the study published on December 21, 2022, in the Journal of American Heart Association, a positive correlation between drinking two or more cups of coffee and the risk of cardiovascular death in people with severe hypertension was shown. 

The previous study found that drinking one cup of coffee a day and daily tea consumption did not increase the risk of death from cardiovascular disease at any blood measurement. 

It showed that drinking one cup of coffee can lower the risk of death from a heart attack or stroke in healthy individuals.

Furthermore, separate studies found that drinking one cup of coffee regularly may lower the risk of chronic illnesses such as Type 2 diabetes and some cancers. 

It may also help to decrease the risk of depression, yet it is not clear if this effect is from caffeine or something else in coffee. 

On the other side, drinking too much coffee may increase blood pressure and lead to anxiety, health palpitations, and difficulty sleeping.

This study aimed to investigate whether drinking coffee affects individuals with different degrees of hypertension.

High blood pressure, also called hypertension, is a medical condition in which blood pressure is higher than usual.

High blood pressure forces the heart to work harder to pump blood to the body.

It is created by the force of blood pushing against the walls of blood vessels.

The higher the pressure, the more complex the heart has to pump.

The unit of it is in millimeters of mercury (mm Hg).

According to the American Heart Association and the American College of Cardiology guidelines, hypertension is classified when the blood pressure is 130/80 mm Hg or higher. 

Study participants included more than 6570 men and more than 12000 women, ages 40 to 79 years.

Researchers categorized blood pressure into five categories: optimal and normal (less than 130/85 mm Hg); high normal (130-139/85-89 mm Hg); grade 1 hypertension (140-159/90-99 mm Hg); grade 2 (160-179/100-109 mm Hg); and grade 3 (higher than 180/110 mm Hg). 

The blood pressure measures in grades 2 and 3 were considered severe hypertension in this study. 

Participants provided data through health examinations assessing lifestyle, diets, and medical history for 19 years.  

The data analysis demonstrated that drinking a cup or more coffee a day was associated with twice the risk of cardiovascular disease death compared to those who did not drink any coffee. 

Drinking one cup of coffee daily was not associated with an increased risk of cardiovascular disease death in any blood pressure categories.

Green tea consumption was also not associated with an increased risk of cardiovascular disease death in any blood pressure categories. 

"These findings may support the assertion that people with severe high blood pressure should avoid drinking excessive coffee," said Iso, M.D., Ph.D., M.P.H., director of the Institute for Global Health Policy Research.

"Because people with severe hypertension are more susceptible to the effects of caffeine, caffeine's harmful effects may outweigh its protective effects and may increase the risk of death,” quoted from the research published in the American Heart Association. 

Dustin Kim / Grade 11
Shanghai American School Puxi