Astringent taste in Ayurveda

Astringent taste, also known as 'kashaya rasa' in Ayurveda, is not considered a taste according to modern science, as it is merely a sensation carried by somatosensory fibers to the brain and not perceived by taste buds. This taste is abundant in nature, found in all the green leafy vegetables and raw fruit, along with the bitter taste.

Qualities:

Astringent taste is dry, cold, and heavy.

Actions:

The dryness of this taste reduces water while coldness reduces fire. It pacifies Pita, Kapha, and Rakta while it aggravates Vata. It has very good wound healing properties, haemostasis action(stops bleeding from wounds), reduces secretions, controls diarrhea, controls excessive perspiration,  reduces the flow of urine,

Excess:

If astringent taste is consumed in excess, it will lead to unwanted effects like puckered mouth and throat, gas, constipation, pain in the heart, hoarseness of voice,impotency, blockage of channels, and other vata disorders like paralysis, Bell's palsy, e.t.c. It's not the ideal taste to promote mental well-being. Ayurveda does not advocate consuming raw vegetables in excess. This is totally a Western concept where it is considered fibre-rich and good for constipation and intestinal health. But actually it will increase constipation in the long run because of aggravation of vata in the special seat of vata, i.e. intestine.

Sources:

Most green leafy vegetables and unripe fruits are astringent. Lettuce, cabbage, broccoli, and sprouts are very good examples. Among the fruits persimmon(Japani phal) is astringent.