Plants do not want to be eaten. Like all living things, they also have their defense mechanism that ensures their species’ development and perpetuation. Unlike animals, plants cannot run away from their predators. They just stand bravely still and let chemistry protect them.
Their defenses are in the form of natural pesticide and toxin compounds that ward off herbivire pests. These abilities of the plants to defend themselves despite their inability to move, made them to be one of the most successful living organisms on earth.
Sometimes these plants compounds can be very toxic, like the ones present in hemlock poison which was used in Ancient Greece to kill prisoners, Socrates was sentenced to death by drinking this plant extract.
There are also plant compounds that are non toxic, but very bitter, sour, or sappy, which help the plant ward off insects and animals. These are the plants that we call “edible”, not necessarily “palatable”. It can be consumed by humans without causing immediate harm to the consumer. In fact, some of the compounds present in plants can be helpful to humans not only for nutrition, but also to heal various human sicknesses.
In China, there are more than 16,000 ancient cultivars of flora that are still being used in Traditional Chinese Medicine.
With the advancement in science, people learned to cultivate plants by removing or reducing the compounds that are responsible for their unpleasant taste. It resulted to sapid fruits and vegetable that we know today.
Science experts are now able to observe the bioactivity and bioavailability of phytochemicals and how these plant compounds can help in the preventing, managing and delaying human health disorders. The benefits of tea are attributed to catechins and other active compounds present in the leaves White tea for example is a functional food - it is a beverage, and at the same time can function as an alternative or complementary medicine.