With information from Camila Maciel, Agência Brasil
The usual consumption of more than three cups of coffee of 50 ml per day increases by up to four times the chance of genetically predisposed people having high blood pressure. The finding is part of a study developed at the University of São Paulo (USP) and published in the journal Clinical Nutrition.
A previous study shows, on the other hand, that moderate consumption of coffee (one to three cups per day) has a beneficial effect on some cardiovascular risk factors – particularly blood pressure.
The main author of the study, Andreia Machado Miranda, postdoctoral fellow in the Department of Nutrition of the Faculty of Public Health of USP (FSP-USP), explains that this conclusion draws attention to the importance of the relationship between coffee consumption and high pressure. “Since most people have no idea whether or not they are predisposed to developing high blood pressure, it is best to drink moderately. As far as we know, from our studies and others already published, this moderate consumption is beneficial for heart health, “he said.
The choice of coffee to evaluate this association was given as one of the most consumed beverages among Brazilians. The research points out that it may be protective for heart health if used moderately, but it can also be villainous for people predisposed to hypertension and in exaggerated doses. According to Andreia, this is because coffee is a mixture of more than 2 thousand chemical compounds.
“The hypothesis of our study is that more than three cups may increase the chances [of high blood pressure] for the presence of caffeine. Caffeine is associated with vascular resistance, that is, difficulty with passage of the flow in the vessels, and also causes vasoconstriction, which is contraction at the level of blood vessels, which hinders the passage of the flow and all this causes there is an increase in blood pressure, “he explained.
Polyphenols, in turn, would be responsible for charitable actions. “They are compounds of plant origin that are not synthesized by the body, so they need to be obtained through diet. They have high antioxidant power, have an antithrombotic action, which means they prevent the formation of thrombi in the vessels, and promote an improvement in vasodilation, unlike the effect of caffeine, “said the researcher.
The survey is based on data from 533 people interviewed in the 2008 São Paulo Municipal Health Survey (ISA). The state survey obtained sociodemographic and lifestyle data, such as age, sex, race, per capita family income, physical activity and smoking through a questionnaire applied to more than 3 thousand participants. In addition, information was collected on food consumption and blood collection for biochemical analysis and DNA extraction for genotyping. At home, the volunteers’ weight, height, and blood pressure were measured. For the research developed by Andreia, a representative sample of adults and the elderly was used.
“With all these data, we did the study of association between blood pressure, genetics and coffee influence. It was there that we found that individuals who had a higher score on the score, ie, who were genetically predisposed [high blood pressure] and who consumed more than three cups of coffee a day, had a fourfold chance of having high blood pressure in relation to those who had no predisposition, “explained the researcher.
The research, which is supported by the Foundation for Research Support of the State of São Paulo (FAPESP), will now assess the effect of coffee consumption on patients with cardiovascular disease – particularly acute coronary syndrome caused by coronary artery obstruction, which irrigates the heart. The researchers will evaluate for 4 years the follow-up data of 1,085 patients who suffered acute myocardial infarction or unstable angina and were attended by University Hospital of USP.