June 27, 2012
Moderate Amounts Of Coffee Shield Against Heart Failure
Connie K. Ho for redOrbit.com
The influence of coffee on the heart has been unknown for a period of time. While some studies state that habitual coffee consumption can be harmful, other studies propose that coffee has a protective benefit. Researchers from the Beth Israel Deaconess Medical Center (BIDMC) worked to find how much coffee could affect patients.
Interesting enough, the investigators discovered that moderate coffee drinkers have an 11 percent lower risk of having heart failure.
"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," commented lead author Elizabeth Mostofsky, a post-doctoral fellow in the cardiovascular epidemiological unit at BIDMC, in a prepared statement. "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 project data was pooled from five previous studies, including four completed in Sweden and one completed in Finland. The scientists analyzed the information to study the connection between coffee consumption and heart failure. A total of 140,220 participants self-reported data and included 6,522 heart failure events.
In general, the authors determined that the data showed a “statistically significant J-shaped relationship” between habitual coffee consumption and heart failure. As such, protective benefits start to increase with consumption maxing out at two eight-ounce American servings a day. They found that protection slowly declines as people drink more coffee; when people drink five cups, there is no benefit, and, more than five cups, can lead to possible bodily harm.
Even though the research doesn´t show distinctly how moderate coffee consumption can shield the heart from failure, investigators believe that the connection between the two could possibly be explained by the relationship between regular coffee drinking, diabetes, and elevated blood pressure. In particular, diabetes and elevated blood pressure are strong risk factors of heart failure.
"There is a good deal of research showing that drinking coffee lowers the risk for type 2 diabetes,” noted senior author Dr. Murray Mittleman, a physician in the Cardiovascular Institute at Beth Israel Deaconess Medical Center and director of BIDMC's cardiovascular epidemiological research program, in the statement. "It stands to reason that if you lower the risk of diabetes, you also lower the risk of heart failure."
Based on past research, scientists also propose that light coffee and caffeine consumption can increase blood pressure.
"But at that moderate range of consumption, people tend to develop a tolerance where drinking coffee does not pose a risk and may even be protective against elevated blood pressure," explained Mittleman in the statement.
However, this particular project was not able to examine the strength of coffee or the differences between caffeinated and un-caffeinated coffee.
"There is clearly more research to be done," says Mostofsky. "But in the short run, this data may warrant a change to the guidelines to reflect that coffee consumption, in moderation, may provide some protection from heart failure."
The study from BIMDC was recently published in the online edition of the journal Circulation: Heart Failure.