High blood pressure (HTA) occurs when the force of blood once morest the walls of blood vessels is consistently too high, causing the heart to work harder to pump blood. Current blood pressure guidelines from the American Heart Association (AHA) and the American College of Cardiology (ACC) define hypertension as blood pressure of 130/80 mm Hg or higher.
However, the blood pressure criteria considered in this study are slightly different from these guidelines: participants’ blood pressure was classified into 5 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); grade 3 (greater than 180/110 mm Hg). Grade 2 and 3 blood pressure was considered severe hypertension.
Coffee always beneficial?
Previous studies have found that consuming a cup of coffee a day may, on the contrary, benefit heart attack survivors, including reducing their risk of death and preventing the risk of another heart attack or stroke. Other studies have documented various benefits of regular coffee consumption, once morest chronic diseases in particular, such as type 2 diabetes and certain cancers. Coffee can also help control appetite; coffee reduces depressive symptoms and increases alertness.
Only well-documented riskits consumption in excess can increase blood pressure and lead to anxiety, heart palpitations and sleep disturbances.
But do the protective effects of coffee also apply to hypertensives?
The study, conducted among more than 18,600 participants, men and women, aged 40 to 79 at inclusion, shows that the consumption of 2 cups of coffee or more per day is associated with a double risk of death from cardiovascular disease in people with severe hypertension vs non-coffee drinkers. The study is indeed the first to identify an association between the consumption of 2 cups of coffee or more per day and mortality from cardiovascular disease in people suffering from hypertension.
During the 19-year follow-up, 842 cardiovascular disease-related deaths were documented. The analysis reveals that:
- the consumption of 2 or more cups of coffee per day is associated with a 2 times greater risk of death from cardiovascular disease in people with blood pressure of 160/100 mm Hg or more vs. non-consumers of coffee;
- no increase in the risk of death from cardiovascular causes is identified with the consumption of a single cup of coffee, and regardless of the blood pressure category;
- no increase in the risk of death from cardiovascular causes is identified with the consumption of green tea, regardless of the quantity consumed.
“People with severe hypertension should avoid drinking too much coffee”explain the researchers who recall that the harmful effects of caffeine may, in this group of patients, outweigh its protective effects.
The benefits of green tea -and the absence of adverse effects- are explained by the presence of polyphenols, antioxidant and anti-inflammatory micronutrients. However, further studies are needed on the possible benefits of green tea in people with hypertension. Finally, these coffee vs. tea results may still be surprising given that both coffee and tea contain caffeine; however, coffee slightly more than tea: according to the US FDA, a cup of green or black tea contains 30 to 50 milligrams of caffeine, and a cup of coffee contains more than 80 to 100 milligrams.
We will therefore retain this recommendation ofvery moderate coffee consumption for patients suffering from severe hypertension.