NEW ORLEANS, Louisiana -- Chocoholics were given further reason to rejoice Saturday when a small clinical study showed that dark chocolate improves the function of blood vessels.

While the researchers cautioned against bingeing on bon bons, they said the findings of the trial were clear and called for larger such studies to confirm the results.

"In this sample of healthy adults, dark chocolate ingestion over a short period of time was shown to significantly improve (blood vessel) function," said Dr. Valentine Yanchou Njike of Yale Prevention Research Center, a co-investigator of the study.

The results, presented at the annual American College of Cardiology scientific meeting in New Orleans, Louisiana, add to mounting evidence of the health benefits of dark chocolate.

During the six-week trial, 45 people were given 8 ounces (227 grams) of cocoa without sugar, cocoa with sugar or a placebo each day.

An upper arm artery's ability to relax and expand to accommodate increased blood flow -- known as flow mediated dilation, or FMD -- was measured using high-frequency ultrasound before and after daily cocoa or placebo consumption.

Of the 39 subjects who completed the trial, FMD improved significantly in both cocoa groups -- by 2.4 percent among those who had it without sugar and 1.5 percent among those who had it with sugar. It dropped 0.8 percent in the placebo group.

"While the findings from this study do not suggest that people should start eating more chocolate as part of their daily routine, it does suggest that we pay more attention to how dark chocolate and other flavonoid-rich foods might offer cardiovascular benefits," Njike said.