Food is more than just a source of energy - it contains a variety of chemical compounds that can have very different effects in the body. Some of these substances are produced unintentionally during heating or processing. They are sometimes suspected of being harmful to health and are therefore closely examined. At the same time, many plant-based foods contain bioactive substances with potentially positive effects. One example of this is anthocyanins - coloring plant substances that are found in berries, among other things, and have antioxidant properties. In this lecture, we will look at both sides: risky and protective ingredients in our food. Using current research and our own human studies, we will show how these substances work in the body, what modern food analysis is finding out about them and why food chemistry is key to evaluating our diet.