Blue tea: benefits and harm, contraindications

Tea drinking has long been a tradition in the culture of our people. Many people start their morning and end their day with tea. Some prefer black, others - green. There are fans of various additives in the drink, which gives it a variety of tastes. In the summer heat, they remember hibiscus - red tea. But most have not even heard of blue tea. But it exists and is an elite expensive variety.

What is blue tea made of?

Blue tea is obtained from the flowers and leaves of the Thai orchid by drying and fermenting them.

Clitoria ternatea L. (Clitoria ternatea), [ 1 ] is an evergreen ornamental vine native to tropical Asia, known as butterfly pea, and a member of the Fabaceae family. It is common in tropical areas such as Asia, the Caribbean, Central and South America. It produces large blue flowers, which is where the tea gets its name. Clitoria ternatea is widely used as a traditional herbal medicine. In addition to its biological activity, the Clitoria ternatea flower is a source of natural food coloring and a blue-colored drink worldwide. Its root extract is used medicinally to treat whooping cough and in Ayurvedic practice. [ 2 ]

The tradition of making the drink comes from Thailand, where it is called nam dok anchan. Flowers are often used as food coloring. They are picked at dawn, so that the buds are still closed, and only by hand. First, they are dried in the open air, until the core of the flower is wet and the outer part is already dry, then they are oxidized. Before packaging, they are twisted into spirals.

The taste of blue tea

Those who have tried blue tea note its unique light aroma and taste, slightly reminiscent of iodine. At first glance, nothing special, but something makes you return to it again and again and want to drink another cup of the drink.

During the brewing process, the water turns blue and the aroma acquires notes of flowers, wild mushrooms, and other unusual shades.

Uses of blue tea

In addition to food pleasure, blue tea perfectly quenches thirst, relieves anxiety. In addition, antioxidants contained in tea have a beneficial effect on the condition of the skin, [ 3 ] nails, hair, and can be recommended for use in the treatment of various types of skin wounds. [ 4 ] Can be used to prevent the progression of cognitive impairment in patients with vascular dementia and Alzheimer's disease. [ 5 ] Cyclotides from C. ternatea can be used for chemosensitization in the treatment of cancer. [ 6 ]

Types of blue tea

There are many varieties of blue tea, differing in the country of origin and degree of fermentation. Blue tea from Thailand "Nam Dok Anchan", mentioned above, can be found in the trade network under the name "blue purple "Chang shu anchan"", "butterfly pea tea", "clitoria ternate", "butterfly pea", from versions of the translation of the name of the plant.

There is also Chinese blue tea. It is related to the so-called oolongs - semi-fermented teas. The raw material for it is the tea bush, not the ternate clitoria. Due to the incomplete processing of the tea leaf, but only its edges, when brewing, an unusual color is obtained. These teas are called blue-green, because something in between blue and black is obtained. Depending on the degree of fermentation, the color of the drink also differs.

There are several varieties: Dong Fai Mei Ren, Feng Huang Dan Cong, Da Hong Pao Tea. The latter is a very expensive variety. All of them are characterized by excellent aroma and taste.

Vietnamese blue tea is ordinary tea leaves flavored with the flowers of the tropical plumeria tree. Its flowers are white, red, purple, and bluish. They give a very pleasant fresh, slightly citrusy aroma with a hint of jasmine. Plumeria, blooming blue, gives the drink the corresponding color.

Tea gourmets value not only a high-quality and unusual drink, but the entire tea ceremony is important to them. Another category of people ignores this, and it is for them that blue tea producers have provided packaging in bags for quick preparation.

How to brew blue tea flowers correctly?

You can feel the real taste of blue tea only by brewing it correctly. To do this, rinse a porcelain or glass teapot with boiling water, pour 2 teaspoons of raw materials into it and pour in a small amount of hot water (80-90ºС). Literally after 10 seconds, drain it and fill the glass again, leave for 5 minutes, pour into cups.

The tea is ready, you can add sugar, honey, lemon, although true connoisseurs drink it just like that. It is good both hot and cold. Interestingly, the brew can be used up to 3 times, this does not worsen the properties of the tea. It should be drunk in moderation, several times a day, some sources recommend only 1-2 times a week.

Health benefits of blue tea

The chemical composition of the plant has not been sufficiently studied, but the components found include saponins, malonylated flavonol glycosides, [ 7 ] flavonoids, carbohydrates, a number of fatty acids (palmitic, stearic, oleic, linoleic and linolenic acids), tannins, antioxidants, high-molecular peptides, cyclotides. This entire "set" provides the following beneficial properties of blue tea:

• eliminates insomnia;
• relieves stress;
• calms;
• improves memory, attention, [ 8 ], [ 9 ];
• has a significant hepatoprotective effect in liver damage caused by drugs; [ 10 ]
• antimicrobial and diuretic action; [ 11 ]
• antidiarrheal activity. [ 12 ]

Studies have reported antiplatelet, vasodilatory, antipyretic, anti-inflammatory, analgesic [ 13 ], [ 14 ], nootropic, anxiolytic, antidepressant, anticonvulsant and antistress [ 15 ] properties of Clitoria ternatea, it exhibits antidiabetic [ 16 ], antiasthmatic and antioxidant activity.

Recently, it was reported that the aqueous extract of Clitoria ternatea flowers inhibited digestive enzymes such as intestinal α-glucosidase and pancreatic α-amylase in vitro [ 17 ]. It exhibited larvicidal activity against three major mosquito vectors Aedes aegypti, Culex quinquefasciatus and Anopheles stephensi. [ 18 ]

Contraindications for use

Blue tea is contraindicated for pregnant women, during lactation, in case of intolerance to the chemical composition of the plant, anemia. It has the property of thinning the blood, therefore, when taking drugs that reduce blood clotting, you need to take this fact into account.

Harm of blue tea

Having a pronounced sedative effect, blue tea can cause harm to people whose profession or hobby is associated with the severity of reactions, for example, driving a car. The appearance of an allergy to the plant is also possible.