It might seem too good to be true, but dark chocolate is good for you and scientists now know why. Dark chocolate helps restore flexibility to arteries while also preventing white blood cells from sticking to the walls of blood vessels. Both arterial stiffness and white blood cell adhesion are known factors that play a significant role in atherosclerosis. What's more, the scientists also found that increasing the flavanol content of dark chocolate did not change this effect. This discovery was published in the March 2014 issue of The FASEB Journal.

"We provide a more complete picture of the impact of chocolate consumption in vascular health and show that increasing flavanol content has no added beneficial effect on vascular health," said Diederik Esser, Ph.D., a researcher involved in the work from the Top Institute Food and Nutrition and Wageningen University, Division of Human Nutrition in Wageningen, The Netherlands. "However, this increased flavanol content clearly affected taste and thereby the motivation to eat these chocolates. So the dark side of chocolate is a healthy one."

To make this discovery, Esser and colleagues analyzed 44 middle-aged overweight men over two periods of four weeks as they consumed 70 grams of chocolate per day. Study participants received either specially produced dark chocolate with high flavanol content or chocolate that was regularly produced. Both chocolates had a similar cocoa mass content. Before and after both intervention periods, researchers performed a variety of measurements that are important indicators of vascular health. During the study, participants were advised to refrain from certain energy dense food products to prevent weight gain. Scientists also evaluated the sensory properties of the high flavanol chocolate and the regular chocolate and collected the motivation scores of the participants to eat these chocolates during the intervention.

"The effect that dark chocolate has on our bodies is encouraging not only because it allows us to indulge with less guilt, but also because it could lead the way to therapies that do the same thing as dark chocolate but with better and more consistent results," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "Until the 'dark chocolate drug' is developed, however, we'll just have to make do with what nature has given us!"