A little piece a day keeps depression away, or at least lowers the risk by 70%, according to a new study of 14,000 adults.

The same link was not found for milk chocolate, or for sugar in general, which means it may be something special in the dark chocolate itself. There are many possibilities. Dark chocolate has flavanols that protect brain cells, as well as other ingredients that improve mood like anandamine and phenylethylamine, a neuromodulator. Other research has found that dark chocolate improves memory and reduces the risk of diabetes and heart disease, particularly when it’s greater than 70% dark.

I wouldn’t overdue the dark chocolate however. Limit to 1-2 ounces a day. Dark chocolate can cause migraines, insomnia (it has more caffeine per ounce than coffee), and kidney stones. It’s also not good for the teeth – best to brush after eating it.

It’s possible these results were due to other factors than dark chocolate itself. For example, it could be that health-minded people choose dark chocolate because of all the good news around it. However, the link remained after adjusting for education, age, income, marital status, weight, medical illnesses, physical activity, smoking status, alcohol intake, and total intake of calories and sugars.

Learn more about dietary changes that can treat depression.