High coffee intake is associated with mortality from cardiovascular diseases in hypertensive individuals

High coffee intake is associated with mortality from cardiovascular diseases in hypertensive individuals

High coffee intake is associated with mortality from cardiovascular diseases in hypertensive individuals

A study published in Journal of the American Heart Association describes that excessive coffee consumption may increase the risk of cardiovascular disease-related mortality in people with severe hypertension.

High coffee intake is associated with mortality from cardiovascular diseases in hypertensive individualsStudy: Coffee and green tea consumption and cardiovascular disease mortality among persons with and without hypertension. Image credit: Bohdan Malitskiy / Shutterstock

Background

Coffee consumption is known to reduce the risk of hypertension and related mortality in the general population. However, it can cause a transient increase in blood pressure in people with hypertension.

Evidence shows that the beneficial effect of coffee consumption depends on the individual’s blood pressure level. In patients with severe hypertension, coffee can cause an acute increase in blood pressure, increasing the risk of cardiovascular diseases.

On the other hand, consumption of green tea is known to lower blood pressure in patients with hypertension. Moreover, green tea reduces the risk of all-cause mortality and cardiovascular disease-related mortality in the general population.

In the current study, researchers investigated the association between coffee or green tea consumption and the risk of cardiovascular disease-related mortality in Japanese people with varying degrees of hypertension.

Study design

A total of 18,609 people, including 6,574 men and 12,035 women, from 24 communities across Japan were included in the study. Participants were asked to complete questionnaires to collect data on demographic characteristics, medical history, lifestyle, and diet.

Participants’ baseline blood pressure was measured by trained personnel. Based on blood pressure levels, participants were categorized into five groups, including optimal and normal blood pressure, high-normal blood pressure, stage 1 hypertension, stage 2 hypertension and stage 3 hypertension.

Important observations

The study investigated the relationship between coffee consumption rates and baseline characteristics of participants belonging to each blood pressure category. A higher rate of coffee consumption was observed among younger participants, current smokers, current drinkers and fewer vegetable consumers. In addition, participants with higher total cholesterol and lower systolic blood pressure were likely to drink more coffee.

The study also investigated the relationship between rates of green tea consumption and baseline characteristics of participants in each blood pressure category. Higher rates of green tea consumption were observed among older participants, frequent fruit eaters, and employed participants.

An association between higher rates of green tea consumption and lower levels of total cholesterol was observed among participants with stage 2-3 hypertension.

Coffee consumption and risk of mortality from cardiovascular diseases

A total of 842 deaths related to cardiovascular disease occurred during the 18.9-year follow-up period.

Consumption of two or more cups of coffee per day was found to increase the risk of cardiovascular disease-related mortality among participants with stage 2-3 hypertension. In contrast, no such association was observed among participants with optimal and normal blood pressure, high-normal blood pressure, or stage 1 hypertension.

Green tea consumption and risk of mortality from cardiovascular disease

Green tea consumption was not found to increase the risk of cardiovascular disease-related mortality among participants with stage 1 to 3 hypertension.

Among participants with high normal blood pressure or optimal/normal blood pressure, consumption of 5-6 cups or 1-2 cups of green tea per day slightly reduced the risk of cardiovascular disease-related mortality.

Green tea.  Image credit: Den Edryshov / ShuuterstockGreen tea. Image credit: Den Edryshov / Shuuterstock

Significance of the study

The study found that high levels of coffee consumption may cause a two-fold increase in the risk of cardiovascular disease-related mortality among people with severe hypertension, but not among people without hypertension or stage 1 hypertension.

The study could not find any negative effect of green tea consumption on the risk of cardiovascular disease-related mortality among people with mild or severe hypertension.

Certain components of caffeinated coffee, including chlorogenic acid, magnesium, and trigonelline, are known to have health benefits, including reduced blood cholesterol levels, inflammation, and improved endothelial function. These positive effects cancel out the negative cardiovascular effects of caffeine in the general population.

Taking into account the findings of the current study, the researchers suggest that the greater sensitivity of people with severe hypertension to the harmful effects of caffeine may actually negate its health benefits and increase the risk of death.

Caffeinated green tea, on the other hand, contains high levels of polyphenols, including epigallocatechin-gallate. Polyphenols have several health benefits, including anti-inflammatory, antioxidant, lipid-lowering, and blood pressure-lowering properties. The positive health effects of green tea catechins are enough to cancel out the negative cardiovascular effects of caffeine.

title_words_as_hashtags]

Leave a Comment

Your email address will not be published. Required fields are marked *