Coffee is one of the most widespread and loved drinks in the world but at the same time also one of those capable of generating the most debates between doctors and nutritionists.
In fact, there are those who argue that it is absolutely beneficial for health and those who argue that it is much less so and that one should not overdo it.
Getting a precise idea and making your way through the numerous theses may seem difficult but the reality is that there is no absolute truth, but that much depends on the aspects that are taken into consideration, on the starting health conditions of the people and on their style of life.
If a few cups of coffee a day have no effect on those who are in a general state of good health, they could be dangerous for people suffering from high blood pressure because it would increase the risk of death due to stroke or heart attack.
This is what emerged from a recent Japanese study.
What does the research support
Although coffee is rich in precious and beneficial antioxidants, it must not be forgotten that it also contains high percentages of caffeine, a powerful natural stimulant that negatively affects various functions of the body, including the sleep routine and, above all, cardiovascular health.
The attention of new Japanese research, published in the Journal of the American Heart Association, focused precisely on this last aspect, which established that people with very high blood pressure should strongly limit the consumption of coffee throughout the day. In fact, it would be enough to drink a couple of cups a day to see the risk of dying from a heart attack, stroke, or other types of cardiovascular disease doubles.
But be careful, the experiment was conducted with American measurements, and a cup corresponds to 8 ounces, therefore 240 ml.
Since it is a long coffee, however, the comparison with the Italian espresso cannot be made only on the basis of the size of the cup.
Indeed, a long coffee contains from 80 to 100 milligrams of caffeine, while an espresso, although usually around 35, can contain between 50 and 80 mg of caffeine, and a 50 ml cup made with a mocha up to 120 mg.
The importance of the discovery
Coffee, on the other hand, would not have the same effect on people with lower blood pressure levels, who according to research would not be affected by a similar intake.
The latter aspect is not surprising and is not at all new given that previous studies had already revealed it, even going so far as to suggest that a cup of coffee a day could help reduce the risk of death following a heart attack or prevent hypertension and heart attacks and stroke in healthy adults.
On the other hand, what makes the recent work innovative is the fact that it has managed to shed light on some specific aspects ignored until now and to demonstrate that drinking too much coffee in some subjects can lead to very serious consequences.
“Our study aimed to determine whether the known protective effect of coffee on the heart also applied to individuals with varying degrees of hypertension. In addition to this, we also examined the effects of green tea in the same population," explained Hiroyasu Iso, senior author of the study and director of the Institute for Global Health Policy Research at the National Center for Global Health and Medicine in Tokyo.
At the same time, the possible incidence of the consumption of green tea was in fact also analyzed, which however, despite also containing caffeine, was found to be irrelevant.
How the study was carried out
The study involved a rather large number of participants overall: 6,574 men and 12,035 women who decided to join the Japan Collaborative Cohort Study for Evaluation of Cancer Risk between 1988 and 1990 and who were followed up until 2009.
Coming from 30 different Japanese communities, all individuals were aged between 40 and 79 when they signed up for the program and after self-reporting their daily coffee and tea consumption, diet, lifestyle, and medical history were observed for the established period of time and evaluated using questionnaires and self-reports but also data relating to their health examinations.
To establish the impact of coffee, consumption was self-reported and blood pressure was measured at a single point, with no changes taken into account.
At the end of the observation, it was therefore found that participants with severe hypertension who drank two or more cups of coffee a day had a double risk of dying from cardiovascular disease, compared to those who did not drink coffee at all.
Even limiting yourself to just one cup of coffee or replacing it with any amount of green tea would not increase your risk, regardless of your blood pressure level.
