By John Salak –
In yet another report on the medical love-hate relationship with coffee, the American Heart Association (AMA) warns that drinking two or more cups of coffee a day may double the risk of death from cardiovascular disease for people with severe high blood pressure.
Fortunately, those without high blood pressure don’t have to worry much about drinking a few cups of Java every day, according to the AMA report.
Does that clear things up on coffee consumption? Not really. Apparently, the same study found that one cup of coffee and a daily dose of green tea did not increase the risk of cardiovascular disease death at any blood pressure measurement, even those both drinks contain caffeine.
To confuse matters further, a previous study presented in March 2022 at the American College of Cardiology’s annual session reported that drinking one cup of coffee a day may actually help heart attack survivors by lowering their risk of death after a heart attack. This research also noted that coffee may prevent heart attacks or strokes in healthy individuals. Other studies have cited coffee’s potential to reduce the risk of developing chronic illnesses, such as Type 2 diabetes and some cancers. It may help to control appetite; lower the risk of depression and boost alertness.
Coffee’s mixed bag of help-versus-harm may come down to each individual’s preexisting condition, at least that the researchers involved in the AMA study wanted to examine.
“Our study aimed to determine whether the known protective effect of coffee also applies to individuals with different degrees of hypertension, and also examined the effects of green tea in the same population,” Dr. Hiroyasu Iso, the study’s senior author, explained. “To the best of our knowledge, this is the first study to find an association between drinking two or more cups of coffee daily and cardiovascular disease mortality among people with severe hypertension.”
Iso’s research into hypertension, also known as high blood pressure, involved tracking data from more than 6,500 men and 12,000 women over a 19-year period. The individuals involved ranged in age from 40 to 79 and were located in 45 Japanese communities. The participants provided data through health examinations and self-administered questionnaires assessing lifestyle, diet and medical history.
During the tracking period almost 850 cardio-related deaths occurred and drinking two or more cups of coffee a day was associated with twice the risk of cardiovascular disease death in people with high blood pressure compared to those with severe hypertension who did not drink any coffee. Green tea consumption was not associated with an increased risk of cardiovascular disease mortality across any blood pressure categories.
“These findings may support the assertion that people with severe high blood pressure should avoid drinking excessive coffee,” said Iso. “Because people with severe hypertension are more susceptible to the effects of caffeine, caffeine’s harmful effects may outweigh its protective effects and may increase the risk of death.”
The AMA study also found that people who tended to drink more coffee were more likely to be younger, current smokers and drinkers, who ate fewer vegetables and had higher total cholesterol levels and lower systolic blood pressure.
Green tea’s apparent benefits may stem from the presence of polyphenols, which are micronutrients with healthy antioxidant and anti-inflammatory properties found in plants.
Iso’s research adds another twist to the debate over coffee’s ultimate benefits and dangers, but it does little to end the arguments. In the meantime, those with hypertension should remain vigilant to all manner of lurking threats.