In their study, which appeared in the journal Clinical Nutrition, they looked at the relationship between genetic predisposition, daily coffee intake and blood pressure and found that genetically at-risk individuals who consume more than three cups of coffee a day have a higher likelihood of developing hypertension.
The healthfulness of drinking coffee has been the subject of debate for years. While some studies link the popular morning drink to different health problems, such as high blood pressure and insomnia, other studies highlight the benefits of moderate coffee consumption, which include a faster metabolism and better brain performance. (Related: Researchers say coffee has a number of health benefits you probably never heard of.)
In a previous study, lead author Andreia Machado Miranda found that drinking one to three cups of coffee a day helped decrease cardiovascular risk factors, such as blood pressure and blood homocysteine levels. This study, however, did not include genetic analysis, which led Miranda and colleagues to conduct another investigation to determine if coffee consumption influenced blood pressure in people genetically predisposed to hypertension.
The researchers calculated the genetic risk scores of 533 older adults who took part in the Sao Paulo City Health Survey, a cross-sectional population-based survey conducted between 2008 and 2009. This study reported no correlation between high blood pressure and drinking up to three cups of coffee a day.
The researchers based the genetic risk scores of the participants on four common DNA sequence variations, which have previously been associated with a predisposition to high blood pressure. The more gene variations an individual had, the higher his genetic risk score.
Upon analyzing each participant's genetic risk score, daily coffee consumption and blood pressure, the researchers found that a high genetic risk score and high coffee intake corresponded to a greater risk of high blood pressure.
In particular, drinking more than three cups of coffee daily increased the high blood pressure risk of genetically predisposed participants fourfold.
The researchers said that these findings highlight the importance of reducing coffee intake for individuals who have a high genetic risk of developing hypertension, a known risk factor for cardiovascular disease.
Despite their findings, Miranda says that drinking coffee still offers significant health benefits. When consumed in moderation, coffee can protect cells from oxidative damage and inflammation because of its rich antioxidant content.
Coffee is also rich in polyphenols, particularly chlorogenic acid. This compound helps lower blood sugar levels by promoting glucose uptake by cells and increasing insulin sensitivity. Chlorogenic acid also helps regulate blood pressure.
According to the American Heart Association (AHA), caffeine, the natural stimulant in coffee, can help improve mood, enhance athletic performance and reduce the risk of dementia.
Drinking coffee every day is not bad for your health, so long as you consume moderate quantities. As many studies suggest, coffee consumption should be limited to no more than three cups a day so you can enjoy its heart and other health benefits without worries.