June 27, 2012 (Boston, Massachusetts) — Once again, a study points to coffee as cardioprotection, at least when it's consumed in moderation. A meta-analysis of prospective studies mostly of people with no MI history saw their risk of incident heart failure follow a J-shaped curve in relation to coffee intake . The risk reached its lowest at daily consumption of four Scandinavian-style servings, or perhaps two cups by US standards.
"That protection slowly goes away with five or more cups per day," according to lead author Dr Elizabeth Mostofsky (Beth Israel-Deaconess Medical Center and Harvard School of Public Health, Boston, MA). And at levels of 10 European cups per day or more, she told heartwire , "there may potentially be harm."
The meta-analysis of five trials, four of which were conducted in Sweden and the fifth in Finland, was published online June 26, 2012 in Circulation: Heart Failure.
In light of the findings, current heart-failure prevention guidelines based on the view that coffee raises risk  should be reconsidered, according to Mostofsky. Those recommendations "were based on the best available evidence at the time, but it didn't account for other differences between coffee drinkers and non–coffee drinkers."
Indeed, the new meta-analysis is consistent with abundant other evidence for lower risk of diabetes, stroke, and other conditions with increasing coffee intake.
The combined five-study population consisted primarily of people without a history of cardiovascular disease or hypertension, and the relative-risk reductions with coffee intake were unrelated to sex and history of MI or diabetes in subgroup analyses. And on their own, the individual studies adjusted for demographics and standard cardiovascular risk factors such as cholesterol levels.
Relative Risk (RR) of Incident Heart Failure* by Daily Cups of Coffee (Northern-European Style) in a Five-Study Meta-Analysis
|Cups/day||RR (95% CI)|
*p =0.02 for nonlinearity and for overall significance of curve
Coffee's prowess in warding off heart failure is probably indirect, according to Mostofsky, who pointed to evidence suggesting coffee cuts the risk of diabetes. "And since that’s a strong risk factor for heart failure, presumably these findings may be showing that coffee consumption is lowering the risk of type 2 diabetes, and that in turn is associated with a lower risk of heart failure."
The study was supported by the National Institutes of Health. Neither Mostofsky nor her coauthors had disclosures.
Heartwire from Medscape © 2012 Medscape, LLC
Cite this: Coffee vs Heart Failure: A Few Cups Per Day Protects - Medscape - Jun 27, 2012.