Cultivated plants are the foundations of the modern human civilization because they are used as food, building material and source of great number of useful chemical compounds. Original species have been greatly transformed during domstification. Those used for food, selected traits were amount of yield, ease of harvest or taste and digestibility improvement. Better taste and digestibility were, in most cases, the result of removal of some toxic compound or antinutrient. Also, lots of food preparation techniques were developed to displace or neutralize unwanted chemicals form plants. Antinutrents are found in every plant species eaten every day around the world. Wheat contains phytic acid which binds metal cations and hinders their apsorption, beans has lectins which are able to cause haemolysis, soy sinthesises protease inhibitors to impede protein digestion, potato has glycoalkaloids which are poisonous to humans and plants from Brassicaceae fammily contain glucosinolates which have detrimental effect on thyroid gland. Even though those chemicals are generally recognised as unwanted, they also have desirable properties. They are responsible for caracteristic taste and aroma of some foods, they can protect teeth or blunt blood glucose spikes after meal. When disussing poisons, it is useful to have in mind that the dose makes the poison.