A just came across a recent study that demonstrated that green tea could significantly improve depression symptoms, in particular anhedonia.
Green tea (Camellia sinensis) extracts, as well as their main component, the polyphenol
epigallocatechin-3-gallate (EGCG), reportedly have antistress, anticancer, and
antioxidant effects. Recent studies suggest a beneficial association between green tea
consumption and symptoms of depression; however, the underlying mechanism behind
that association is unclear. Anhedonia, the inability to experience pleasure, is a
characteristic of depression, marked by reduced pleasure, altered motivation, and
disturbed reward learning.1,2 A reduced reward-learning function has been linked to
persistent anhedonia in depressed patients.3
“It has been evidenced that reduced dopamine neurotransmission might
contribute to the anhedonia and loss of behavioral incentive in depressive disorder,
therefore it is important to examine the regulatory role of green tea on the brain circuitry
activated by reward learning,” write the authors.
Compared with the control treatment, the green tea produced significantly greater
improvements in the MADRS (P<0.01) and HRSD-17 (P<0.001) total scores.
I’ve been drinking green tea occasionally and noticed that it seemed more stimulating than regular tea. This seemed odd to me since green tea has approximately half the amount of caffeine compared to black tea. According to this study and others the stimulating effects could be due to an increase in dopamine activity in the reward center of the brain.
Green tea is recommended for Pitta and Kapha types in Ayurveda. Pitta types are said to have more problems with inflammation so green tea, which has an astringent quality to it, would be recommended. Inflammation has been shown to in turn to be associated with depression. I found one recent journal article in addition that supports the idea that tea, black or green, has anti-inflammatory properties.