What Exactly Are Secondary Plant Compounds
The importance of energy providers such as carbohydrates, fats, and proteins, as well as the mineral content and vitamins, along with the trace elements, is long integrated into our eating habits. In recent years, however, a group of plant components - secondary plant compounds - has also come into the consumer's view. Quantitatively, these substances make up only a small part of daily nutrition. Yet, even though humans take in only 1 to 2 g (depending on dietary habits) of these secondary plant compounds with a balanced mixed diet, they ingest many different individual substances with this amount.
Secondary plant compounds are a group of chemically very diverse molecules that, as the name suggests, occur exclusively in plants. They are produced in contrast to carbohydrates, fats, proteins, and dietary fibers, which are formed in the primary plant substance metabolism, in what is called secondary metabolism. The term "secondary" does not make a statement about the importance of these substances. For plants, they fulfill a multitude of very important functions. They serve, for example, as defense against pests and diseases or as growth regulators and also as precursors to colorant production. Given their great significance for the plant, it was assumed that these substances could also have an effect in the human body. Today we know that such pharmacological effects are indeed present. Secondary plant compounds can have both health-promoting and harmful effects on the body.
Although their number is so large, secondary plant compounds can be classified into different substance classes based on their molecular structure. In science, several main substance classes are usually used for this purpose. However, there are numerous other compounds that cannot be assigned to this scheme. The most important representatives include carotenoids, saponins, phytosterols, glucosinolates, flavonoids, phenolic acids, protease inhibitors, phytoestrogens, isoflavonoids, lignans, monoterpenes, and sulfides.
What Do Secondary Plants Cause
The antioxidant effect of secondary plant compounds has been investigated for a long time. Here, it is not only the delay in the aging process that is considered but especially an anticarcinogenic effect, i.e., cancer prevention. Antioxidants capture harmful radicals that constantly arise in our metabolism and render them harmless.
Furthermore, their effects on the immune system are being researched. In some representatives, a hormonal impact has been identified. This context also refers to phytoestrogens.
Flavonoids have a broad spectrum of action. They occur in citrus fruits and onions but also in many medicinal plants such as hawthorn, ginkgo, or chamomile. Their effect is well known from traditional medicine. They act anti-inflammatory and possess not only antioxidant properties but also protect blood vessels. Additionally, they support the effects of other components.