Nature of increase and decrease

vṛddhi: samānai: sarveṣāṃ viparītai: viparyaya: |
Equal qualities lead to increase, and opposing qualities lead to decrease.
For example, dryness is
the quality of Vata. If a Vata body type person exposes himself to dry cold weather, his dryness and in turn Vata will increase, leading to dry skin. In the same way, oiliness is opposite quality of
dryness. If he applies oil to the skin, then the dryness and related Vata is decreased.

Six tastes
Svadu – Madhura – sweet, Amla – Sour, Lavana – Salt, Tikta – Bitter, Ushna – Katu – Pungent,
Kashaya – Astringent are the six types of Rasa.
They are successively lower in energy. That means, Sweet taste imparts maximum energy to body and the astringent, the least.
Effect of tastes on Tridosha

tatrādyā mārutaṃ ghnanti traya: tiktādaya: kapham |
kaṣāya tikta madhurā: pittamanye tu kurvate ||
In the list of tastes, the first three, i.e. Sweet, sour and salt mitigates Vata and increases Kapha.
The last three, i.e. bitter, pungent and astringent tastes mitigates Kapha and increases Vata
Astringent, bitter and sweet taste mitigates Pitta. Sour, salt and pungent tastes increase Pitta