Nitric oxide signals the blood vessels to dilate or expand. It has a role in transporting oxygen to the tissues. It is produced when the body relaxes. Anything that helps the body to relax, or anything that combats stress, can help the supply of oxygen to the cells and reduce blood pressure.
There are over 300 different chemicals found in chocolate. Undoubtedly there are benefits in chocolate that have not yet been discovered in a laboratory. However many people would attest to the fact that they feel good when they have eaten some chocolate. Perhaps we don't really need to know every action of this delicious food. It is good to know though that amongst other nutrients it contains potassium, magnesium and vitamins B1, B2, D and E.
Enjoy good health,