In June 2022, a study published in the scientific magazine Nutrients explored the potential mechanisms behind depression under laboratory conditions in mice. Researchers were specifically interested in the impact of green tea consumption on biological responses to stress and inflammation in the brain. The study focused on four main ingredients typically found in green tea, including caffeine, theanine, arginine, and epigallocatechin gallate.
The findings of this research revealed that consumption of green tea components with specific CE/TA ratios, particularly 2 to 8, has the ability to suppress depression-like behavior, adrenal hypertrophy, and brain inflammation. This suggests that daily consumption of green tea with a CE/TA ratio of 4-5 can benefit individuals in terms of improving mood.
In May 2022, another study published in the Journal of Nutritional Science and Vitaminology explored the correlation between human subjects drinking green tea and the likelihood of experiencing depressive symptoms. This systematic review and meta-analysis of observational studies included a total of 8 observational studies that primarily focused on the Asian population. The findings indicated an inverse relationship between the consumption of green tea and depressive symptoms. A higher daily intake of green tea was associated with a lower frequency of reports concerning symptoms of depression. Based on these findings, it was recommended that the general population should consume 3 cups of green tea each day in order to decrease these symptoms.