Drinking coffee moderately may reduce the risk of heart failure, but drinking too much makes this benefit disappear, according to a new review.
People who drank two cups of coffee a day were 11 percent less likely to have heart failure, compared with people who drank no coffee. Heart failure occurs when the heart cannot pump enough blood to meet the demands of the body, and can be caused by factors ranging from high blood pressure to pregnancy.
Constantly drinking too much coffee, however, negates this benefit: no difference in heart failure risk was seen between non-coffee drinkers’ and those who drank more than three cups a day.
"As with so many things, moderation appears to be the key here," said study author Dr. Murray Mittleman, director of the Cardiovascular Epidemiology Research Unit at Beth Israel Deaconess Medical Center in Boston.
The study showed an association, not a cause-and-effect link.
Still, there is reason to think coffee lowers heart failure risk, the researchers said. Moderate coffee consumption may increase drinkers' caffeine tolerance, which could in turn limit their susceptibility to high blood pressure. Additionally, coffee drinking has been shown to lower the risk of developing Type 2 diabetes. Diabetes and hypertension are major risk factors for heart failure, Mittleman said.
People who have already have heart failure should consume no more than one to two cups of coffee per day, according to the American Heart Association.
The finding "is good news for coffee drinkers, of course, but it also may warrant changes to the current heart failure prevention guidelines, which suggest that coffee drinking may be risky for heart patients,” said study author Elizabeth Mostofsky, a research fellow at the center.
The researchers looked at data collected on 140,220 people in Sweden and Finland who participated in five previous studies. There were a total of 6,522 cases of heart failure between 2001 and 2011. The causes of heart failure often cannot be reversed, but the condition can be treated.
The researchers took into account the differing serving sizes between Europe and the United States (European servings are generally smaller), however, they did not account for coffee's strength or whether the coffee was caffeinated, though they noted that in northern Europe, it typically is.
The study was published yesterday (June 26) in the journal Circulation Heart Failure.
Pass it on: Moderate coffee drinking lowers the risk of heart failure.