Beyond the morning buzz: Coffee's potential health benefits

Coffee drinkers around the world savor the bitter brew on a daily basis. But are there any grounds for concern regarding coffee's effects on the heart? On the contrary: the case for drinking coffee seems to be growing, reports the March 2015 Harvard Heart Letter. Coffee — minus the cream and sugar — is a nearly calorie-free beverage brimming with antioxidants. It also might ease artery-damaging inflammation and deliver a substance that helps the body regulate blood sugar.

"The evidence for the benefits of coffee consumption is even more convincing than it was five years ago, especially when it comes to preventing type 2 diabetes and reducing the risk of heart disease and stroke," says Dr. Frank Hu, professor of nutrition and epidemiology at the Harvard School of Public Health.

Although caffeine is by far the most studied compound in coffee, the beverage is a complex brew that contains hundreds, if not thousands, of bioactive components. Among these are vitamins, minerals, and potent, plant-based anti-inflammatory compounds known as polyphenols. Most likely, it's the combination of these substances, rather than caffeine itself, that confers coffee's potential health benefits.

Caffeine, a mild stimulant, triggers a short-term rise in blood pressure and heart rate. While some coffee drinkers welcome the stimulant effect, others complain that caffeine causes daytime jitters and sleepless nights. Now, researchers acknowledge that a moderate amount of caffeine is fine for most people with heart disease as long as they don't have a heart-rhythm problem.

"People develop tolerance to caffeine within a few days, so the effects cannot be extrapolated to the long term. Over time, caffeine does raise the resting metabolic rate and increase energy expenditure, albeit modestly, so it may actually turn out to be helpful in controlling body weight," says Dr. Hu.

Read the full-length article, "A wake-up call on coffee"