If you drink coffee regularly in moderation, you could reduce your risk of heart failure, according to new research in the American Heart Association’s journal Circulation Heart Failure.
Researchers, analyzing previous studies on the link between coffee consumption and heart failure, found that moderate coffee drinking as part of a daily routine may be linked with a significantly lower risk of heart failure. In contrast, indulging excessively may be linked with an increased chance of developing serious heart problems.
“While there is a commonly held belief that regular coffee consumption may be dangerous to heart health, our research suggests that the opposite may be true,” said Murray Mittleman, M.D., Dr.P.H., senior study author and director of the Cardiovascular Epidemiology Research Unit at Beth Israel Deaconess Medical Center in Boston.
“We found that moderate consumption - which we define as the equivalent of about two typical American coffee shop beverages - may actually protect against heart failure by as much as 11 percent,” he said. “On the other hand, excessive coffee drinking - five to six commercial coffee house cups per day has no benefit and may even be dangerous. As with so many things, moderation appears to be the key here, too.”
Researchers reviewed five high quality prospective studies of coffee consumption and heart failure risk published between 2001 and 2011. Combined, the studies included 6,522 heart failure events among 140,220 males and females. Four of the studies were conducted in Sweden and one in Finland.
The study defines moderate consumption as four Northern European servings per day, the equivalent to about two typical 8-ounce American servings. Excessive coffee consumption is 10 Northern European servings per day, the equivalent to four or five coffees from popular American coffee restaurant chains (servings sizes vary from 9 to 20 fluid ounces per serving).
Despite 20 years of reassuring research, many people still avoid caffeinated coffee because they worry about its health effects. However, current research reveals that in moderation—a few cups a day—coffee is a safe beverage that may even offer some health benefits. The September issue of Harvard Women’s Health Watch weighs the pros and cons of this popular beverage and eases the concerns of moderate coffee drinkers.
The latest research has not only confirmed that moderate coffee consumption doesn’t cause harm, it’s also uncovered possible benefits. Studies show that the risk for type 2 diabetes is lower among regular coffee drinkers than among those who don’t drink it. Also, coffee may reduce the risk of developing gallstones, discourage the development of colon cancer, improve cognitive function, reduce the risk of liver damage in people at high risk for liver disease, and reduce the risk of Parkinson’s disease. Coffee has also been shown to improve endurance performance in long-duration physical activities.
For those who drink coffee to stay alert, new research suggests that you’ll stay more alert, particularly if you are fighting sleep deprivation, if you spread your coffee consumption over the course of the day. For instance, if you usually drink 16 ounces in the morning, try consuming a 2-3 ounce serving every hour or so. Again, moderation is the key.
However, as the September issue notes, coffee is not completely innocent. Caffeine, coffee’s main ingredient is a mild addictive stimulant. And coffee does have modest cardiovascular effects such as increased heart rate, increased blood pressure, and occasional irregular heartbeat that should be considered. Studies have been largely inconclusive regarding coffee and its effect on women’s health issues such as breast health, cancer, and osteoporosis. But, the negative effects of coffee tend to emerge in excessive drinking so it is best to avoid heavy consumption.
Researchers didn’t account for brew strength, but coffee is typically weaker in the United States than it is in Europe. They also didn’t differentiate between caffeinated and decaffeinated coffee, but most of the coffee consumed in Sweden and Finland is caffeinated.
“There are many factors that play into a person’s risk of heart failure, but moderate coffee consumption doesn’t appear to be one of them,” said Elizabeth Mostofsky, Sc.D., lead study author and research fellow at Beth Israel.
When it comes to cardiac disease and hearth health, you’ll get a mixed bag of reports when it comes to the effects of coffee or tea.
Excessive coffee drinking is often thought to lead to higher blood pressure. It’s been shown that drinking 4-5 cups of coffee can raise your blood pressure by 5 points, compared to having only 1 cup. This isn’t a huge amount, but the consequences over the years can lead to heart attacks and strokes. Coffee also may raise homocysteine levels in the blood, which is considered a risk factor for heart attacks.
Then again, a study in 2000 with 20,000 Finnish men and women gave the surprising evidence that coffee drinking didn’t result in a higher incident of heart disease. So perhaps coffee isn’t so bad for your heart after all.
A Scottish Heart Health study, examined people who drank large amounts of coffee or tea. Those who drank coffee had healthier hearts than those who drank tea, which seems to go against the popular opinion that tea is better for you than coffee. The researchers were quick to point out that they did not take lifestyle or diet into account for this study.
“This 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. It now appears that a couple of cups of coffee per day may actually help protect against heart failure.”
The American Heart Association recommends that heart failure patients consume only a moderate amount of caffeine - no more than a cup or two of coffee or other caffeinated beverage a day.
Researchers didn’t definitively say why coffee offers a heart-health benefit. But evidence suggests that frequent coffee drinkers develop a tolerance to the beverage’s caffeine, which may put them at a decreased risk of developing high blood pressure.
In a large, long-term study published in the April 24 on-line issue of Circulation, investigators from the Harvard Medical School report that drinking up to 6 cups or more of coffee per day did not increase the risk of coronary artery disease.
Researchers began following over 44,000 men and almost 85,000 women with no history of cardiac disease or cancer in the 1980s. Each participant was questioned with initial enrollment, and then every 2 - 4 years, about their coffee consumption, and the follow-up was continued until 2000. Over 2100 cases of coronary artery disease occurred in these patients during the average 14-year follow-up period. The investigators found that, when the data was adjusted for age, smoking, weight, diabetes, and alcohol consumption, no additional cardiac risk could be attributed to coffee drinking. Furthermore, they found no evidence that coffee caused elevations in blood lipid levels. Similar results were seen in individuals who drank decaffeinated coffee or tea.
Habitual coffee consumption is also associated with a lower risk of type 2 diabetes, with most studies showing the greatest reduction in risk with higher levels of coffee consumption.
“Diabetes and hypertension are among the most important risk factors for heart failure, so it stands to reason that reducing one’s odds of developing either of them, in turn, reduces one’s chance of heart failure,” Mittleman said.
Other co-authors are Megan Rice, Sc.D., and Emily Levitan, Sc.D.
The study was partly supported by grants from the National Institutes of Health.
Read the current American Heart Association guidelines on preventing heart failure or learn about caffeine and heart disease.
Statements and conclusions of study authors published in American Heart Association scientific journals are solely those of the study authors and do not necessarily reflect the association’s policy or position. The association makes no representation or guarantee as to their accuracy or reliability. The association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific association programs and events. The association has strict policies to prevent these relationships from influencing science content.
NR12– 1090 (Circulation/ Mittleman)
American Heart Association