In order to account for the physiological effects of chemical elements in living organisms using some Biological System of Elements (BSE) established by Markert in 1994 [1], the familiar Periodic Chemical System of Elements (PSE) according to Mendelejew and Meyer from 1869 was completed and modified using the Geochemical System of Elements (GSE) by Railsback [2-4, 5]. BSE goes beyond accumulating essentiality investigations, despite obvious technical and analytical limitations. In correlation among abundances of elements in different samples of biological origins, there are deep-rooted biochemical factors and relationships which these authors began studying and describing in more detail in the late 1990's. Until the end of 2017, the BSCE was referred to as the Biological System of Elements (BSE). Lithium is not considered a vital or essential trace element. However, Li is present in our body and has important functions, especially for the psyche. Specifically, Li is important for mental health. The application of Li as pharmaceutical therapeutic equivalent for bipolar disorders (formerly called manic depressive disorders) is a well-known example of the use of a monovalent cation on neurological therapy. One of the main scientific objectives of this review and future research is the use of functional food in supporting and balancing the therapeutic dose of Li in the human body. In order to describe a possible application of a "functional food therapy by Li” and to meet its “scientific philosophy" a first look was given to Liaccumulating plants. We explain the use of plants containing high amounts of Li and described possible effects of increased Li concentrations in the human body. Finally, we should confirm if "natural food therapy” (for instance “green pills”) can positively support mental human health care benefits by fitting the ratio of Li/neurological diseases. For example, diseases like chronic bipolar disorders. Accordingly, the BSCE will continue to identify and investigate other chemical elements for using them in an effective Functional Food Therapy (FFT) of chronic neurological diseases and possibly other diseases.