While current American Heart Association heart failure prevention guidelines warn against habitual coffee consumption, some studies propose a protective benefit, and still others find no association at all. Amidst this conflicting information, research from Beth Israel Deaconess Medical Center attempts to shift the conversation from a definitive yes or no, to a question of how much. “Our results did show a possible benefit, but like with so many other things we consume, it really depends on how much coffee you drink,” says lead author Elizabeth Mostofsky, MPH, ScD, a post-doctoral fellow in the cardiovascular epidemiological unit at BIDMC. “And compared with no consumption, the strongest protection we observed was at about four European, or two eight-ounce American, servings of coffee per day.” The study published June 26 online in the Journal Circulation: Heart Failure, found that these moderate coffee drinkers were at 11 percent lower risk of heart failure.
Data was analyzed from five previous studies – four conducted in Sweden, one in Finland – that examined the association between coffee consumption and heart failure. The self-reported data came from 140,220 participants and involved 6,522 heart failure events. In a summary of the published literature, the authors found a “statistically significant J-shaped relationship” between habitual coffee consumption and heart failure, where protective benefits begin to increase with consumption maxing out at two eight-ounce American servings a day. Protection slowly decreases the more coffee is consumed until at five cups, there is no benefit and at more than five cups a day, there may be potential for harm.