Munich (dpa / tmn) - Fruits, vegetables and cereals are not only rich in vitamins and minerals, but are also full of secondary plant substances. These fulfill various tasks in the plant.

"Some provide color and aroma, others ward off predators or regulate growth processes," explains Andrea Danitschek, nutrition expert at the Bavarian Consumer Center.

For example, carotenoids and flavonoids color fruits and vegetables in shades of yellow and red. Glucosinolates give radish, cabbage and mustard the typical spiciness.

Secondary plant substances are considered healthy, for example because of their anti-inflammatory properties. However, the results from cell studies and animal experiments cannot simply be transferred to humans. That is why it is controversial to take plant substances in isolation as food supplements.

"It makes more sense to take in secondary plant substances via fruit, vegetables and cereal products," Danitschek recommends. This is how the substances work in a natural combination and there are no overdoses.