Many of us regularly enjoy, or even crave, chocolate at times. As you consider your chocolate choices, opting for dark chocolate may be your best bet. Research continues to identify a variety of health and mental health benefits associated with dark chocolate.

The polyphenols in cocoa and dark chocolate are associated with antioxidant, anti-inflammatory, cardiovascular, mood and other benefits. Milk chocolate, on the other hand, doesn’t have the same concentration of polyphenols.

A recent study of young healthy women found that a single serving of “dark chocolate may have beneficial affect during acute stress due to its ability to buffer cardiovascular reactivity.” A similar affect was not found with milk chocolate.

Researchers have also looked at what happens to the brain when a person eats dark chocolate. A 2018 study found changes in electrical brain oscillations in several regions of the brain after study participants consumed dark chocolate. Dark chocolate may even improve vision, at least temporarily. A small study found that two hours after eating a dark chocolate bar (but not a milk chocolate bar) there were noticeable improvements in participants’ vision. The study did not look at whether the improvements lasted.

Dark chocolate is also associated with beneficial effects on mood and mental health. A 2019 study led by researchers at University College in London looked at data on more than 13,000 adults in the U.S. and their consumption of dark and milk chocolate. Controlling for many other health and lifestyle factors, the study found that individuals who ate dark chocolate had significantly lower odds of reporting depressive symptoms than those who ate no chocolate at all. The positive effects of dark chocolate were not seen with milk chocolate. However, they caution that further research is needed to confirm and clarify the role of dark chocolate in contributing to reduced depression symptoms.

A randomized double-blind study looked at potential mental health benefits of dark chocolate shortly after consuming it and over a period of 30 days. The healthy middle-age participants each received a dark chocolate drink mix (with a high dose of polyphenols, a low dose, or a placebo) each day. After 30 days, those with the high dose of polyphenols experienced a significant increase in calmness and contentedness compared to those with the placebo. They found no impact on mood shortly after consuming the dark chocolate.