Clitoria Ternatea

Clitoria ternatea is a herbaceous perennial vine of the pea family (Fabaceae), recognised worldwide by common names such as butterfly pea, blue pea, Asian pigeonwings and, in Ayurvedic tradition, aparajita ^[1][5]. The plant produces slender climbing stems, elliptic leaflets and showy solitary flowers that are most often a deep blue with a pale yellow throat, although white and mauve forms occur ^[1][5]. Its flat pods hold several seeds, and like other legumes it forms root associations with rhizobia that fix atmospheric nitrogen, which makes it useful as a soil-improving cover and forage crop ^[1].

The species is thought to have originated in tropical Asia, and its scientific name references the Indonesian island of Ternate; it has since been carried throughout the tropics of Asia, Africa, Australia and the Americas ^[1]. The blue petals are edible and have a long history as a natural dye. In parts of Southeast Asia they colour rice dishes and sweets, and steeped as a caffeine-free tea the flowers yield a striking blue infusion that turns purple or pink when an acid such as lemon juice is added ^[1][5]. This pH-sensitive colour shift has made the flower popular in colour-changing drinks and cocktails, although its use as a food additive is not uniformly approved; European authorities have not cleared it as a permitted colour, and at least one spirit product was recalled on that basis ^[1].

The blue colour comes chiefly from ternatins, an unusual group of polyacylated anthocyanins derived from delphinidin 3,3',5'-triglucoside, which are prized for their relative stability and antioxidant behaviour ^[5]. Alongside these pigments the flowers and other tissues carry flavonol glycosides of kaempferol, quercetin and myricetin, together with phenolic acids, triterpenoids and, in the seeds and leaves, a family of stable cyclic peptides called cyclotides ^[4][6]. Extracts of the flower have shown antioxidant, anti-inflammatory, antimicrobial and antidiabetic activity in laboratory assays, which underlies interest in the plant as a functional food ingredient ^[6].

In the folk and Ayurvedic medicine of the Indian subcontinent, Clitoria ternatea has traditionally been regarded as a brain tonic taken to support memory and to calm the mind ^[2]. Pharmacological studies in rodents have reported that extracts of the aerial parts and roots can improve performance on learning and memory tasks while showing anxiolytic, antidepressant, anticonvulsant and antistress effects ^[2]. Work focused on the root has linked these benefits to inhibition of acetylcholinesterase and to protection of hippocampal neurons in models of reduced blood flow to the brain ^[3][4]. This research remains largely preclinical; controlled human trials establishing a cognitive benefit are lacking, and most evidence comes from cell and animal experiments ^[3][6].

As a plant, Clitoria ternatea is not a scheduled or controlled substance, and it is widely traded as dried flowers, teas, powders and flower extracts used for colouring and as dietary supplements ^[1][6]. Regulatory acceptance of the flower as a food colour varies by country, and its standing as a novel food or additive continues to be assessed in some jurisdictions ^[1].

Very well tolerated, with a long history as a food and tea and minimal reported side effects. High doses may cause mild nausea. Human safety data at concentrated doses is limited but the plant is generally regarded as safe; avoid excessive use in pregnancy.