Nov 20, 2013 01:59 PM EST By Staff Reporter, UniversityHerald Reporter

The effects, benefits, and detriments of coffee gained more ground when a recent study showed how caffeine boosted the performance of small blood vessels, which contribute to cardiovascular health, USA Today reported.

The study, presented Wednesday at the American Heart Association's meeting in Dallas (busy month for the AHA), tested 27 healthy, non-coffee drinking adults, ages 22 to 30. A group of researchers, including Masato Tsutsui from the University of the Ryukyus in Okinawa, Japan, gave them two types of coffee - regular and decaf - on separate days. Afterwards, they assessed participants' "reactive hyperemia" in their index fingers, one method by which to measure the efficiency of one's blood vessels, according to USA Today.

While drinking regular coffee, participants' blood vessels (within their index finger) performed 30 percent better (meaning improved blood flow, according to Newsday) than when they drank decaffeinated coffee. The effects of caffeine lasted for 75 minutes.

Tsustui and colleagues also found that caffeine increased blood pressure, an established side effect, and decreased blood flow in the index finger (reported by USA Today), indicating the rate of blood flow is not necessarily related to high vascular function. Rather, the improved performance of the inner lining of the blood vessels is more important, according to Tsutui.

"This is an intriguing observation that may help us understand why consumption of coffee may be beneficial," said former AHA president Dr. Gordon Tomaselli. Previous research had already found a link between heart health and coffee consumption, but those studies couldn't show why, according to Newsday.

Of course, too much of anything is a bad thing - though some research has shown up to two cups of coffee per day yielded its most beneficial effects, Newsday reported.

"Small amounts of coffee may have a benefit, but a higher consumption of coffee definitely raises blood pressure. It definitely raises heart rate, and it makes you more prone to heart palpitations," cardiologist Vincent Bufalino told USA Today. "We see that every day in terms of the use of caffeine in patients. A lot of people sense that a cup of coffee gives them a lift but too much can have negative effects."

To continue the research, future scientists should broaden the study, according to Bufalino. "It's hard to come to broad-based scientific conclusions based on this one small study. The research is limited to one cup of coffee."

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