A new study suggests a cup of coffee can improve small blood vessel function and might be beneficial for cardiovascular health.

The research findings of the small study involving 27 "healthy" adults were presented at American Heart Association's Scientific Sessions 2013, according to a news release:

"On one day, each participant drank one five-ounce cup of either regular or decaffeinated coffee. Then researchers measured finger blood flow with laser Doppler flowmetry, a non-invasive technique for gauging blood circulation on a microscopic level. Two days later, the experiment was repeated with the other type of coffee. Neither the researchers nor the participants knew when they were drinking caffeinated coffee."

According to a news release, participants who drank a cup of caffeinated coffee increased their blood circulation by 30 percent "over a 75-minute period compared to those who drank decaffeinated coffee."  The study participants ranged from ages 22 to 30 and were people who did not "regularly" consume coffee.

"This gives us a clue about how coffee may help improve cardiovascular health," said Masato Tsutsui, M.D., Ph.D., in a statement, lead researcher and a cardiologist and professor in the pharmacology department at the University of the Ryukyus in Okinawa, Japan.

Researchers monitored blood pressure, heart rate, and vascular resistance levels in the study participants, and took blood samples to eliminate the increased blood flow was not due to hormones on blood vessel function.  The heart rate levels of the participants were also the "same" in both of the study groups. 

However, researchers are unclear as to how or why caffeine actually improves the blood flow.  Tsutsui believes caffeine may work to reduce inflammation and "open blood vessels."

"If we know how the positive effects of coffee work, it could lead to a new treatment strategy for cardiovascular disease in the future," Tsutsui said.