Greek coffee may be the key to greater longevity and heart health- a new study finds that many of the oldest people in the world drink a cup of the caffeinated beverage every morning.

Scientists have long marveled at the extremely high rates of longevity among the elderly residents of Ikaria, an island in Greece. Ikaria, which the New York Times called "The Island Where People Forget to Die," boasts one of the highest longevity rates in the world. Only 0.1 percent of Europeans live past the age of 90, while ten times as many Ikarians live past that age. Not only do an extraordinary number of Ikarians live to see a second century; they also tend to remain vigorously active in old age.

A group of cardiovascular health researchers, led by Dr. Gerasimos Siasos of the University of Athens Medical School, decided to investigate whether Ikarians' habit of drinking boiled Greek coffee had anything to do with their health. Specifically, the research team observed the relation between coffee intake and endothelial function.

The endothelium is a layer of cells that lines blood vessels, and its health is affected by aging and lifestyle habits like smoking. Recent studies indicated that moderate coffee intake can boost endothelial health and reduce the risks of heart disease, so the researchers targeted it as a proxy for Ikarians' longevity.

The results, published in the journal Vascular Medicine on March 18, show a strong correlation between Greek coffee drinking habits and endothelial health.

The study included a sample of 71 men and 71 women from Ikaria, out of 673 Ikarians over the age of 65 who are permanent residents of the island. 80 percent had high blood pressure, 23 percent had diabetes, 73 percent had high cholesterol, 17 percent were active smokers, and 22 percent had a history of cardiovascular disease.

Medical professionals collected questionnaires about the participants' health, lifestyles, and coffee habits, and measured health indicators like high blood pressure and endothelial function. The researchers recorded all types of coffee consumed by participants, including boiled Greek coffee, instant coffee, cappuccino, or filtered coffee.

The results showed that over 87 percent of participants drank boiled Greek coffee every day, and that those participants who drank it had better endothelial function than those who drank other types. Even participants with high blood pressure had better endothelial function if they drank boiled Greek coffee.

"Boiled Greek type of coffee, which is rich in polyphenols and antioxidants and contains only a moderate amount of caffeine, seems to gather benefits compared to other coffee beverages," Siasos said in a statement.

The researchers suspect that boiled Greek coffee retains more of the healthful chemical compounds of coffee, since the boiling water is able to extract more from coffee grounds than it would in other methods like filtering. The basic method involves boiling roasted and finely ground coffee in a pot of water with sugar, though there are many possible variations.

Many recent studies have indicated possible health benefits of coffee, and caffeine in general- among them, preventing Alzheimer's disease and heart disease, lowering oral cancer and skin cancer risk, losing weight, and promoting longevity. Still, it's important to note that anything, especially a drug like caffeine, should be consumed in moderation.

More research needs to be done to observe how boiled Greek coffee, or any caffeinated beverage, might boost cardiovascular health. The study only shows a correlation, not a causation, between drinking Greek coffee and greater endothelial health. Ikarians are known to have many other positive habits, like their heart-healthy Mediterranean diets, that are much more strongly linked to better overall health and longevity.

Still, it couldn't hurt to pick up a habit from the world's oldest people. Greek coffee, also known as Turkish coffee, is fairly easy to brew.

Check out this Greek coffee recipe from Chow.com, or watch this video to find out how to make boiled Greek coffee yourself: