Researcher at the Tohoku University located in Japan recently published a study in Clinical Nutrition showing that when older subjects drank green tea they had a lower incidence of depression symptoms than their non tea drinking counterparts.
1,058 women and men who were 70 years or older residing in Sendai, Japan participated in the study. The scientists evaluated depression based on the Geriatric Depression Scale. After the subjects took a dietary questionnaire the results were analyzed for the frequency and type of tea they consumed. Blood samples were then analyzed for a major marker for inflammation, C-reactive protein.
27% of men and 29% of women who participated in the study fell into the range of experiencing mild or sever depressive symptoms. After adjusting the data for other risk factors those who drank more than 4 cups of green tea each day had a 44% lower rate of experiencing depressive symptoms. In regards to sever depressive symptoms those drinking 4 cups of tea had a 52% lower adjusted risk.
The researchers hypothesized that the tea's anti-inflammatory properties were responsible for the increase depression risk. But, the study was unable to show an association between the subjects green tea consumption and C-reactive protein.
They then proposed the anti-stress component of tea, the theanine content, may explain the reduced depression findings. Theanine is an amino acid in green tea. It has the ability to penetrate the brain-blood barrier, which could cause increases in serotonin and dopamine; two compounds associated with improved mood and reduced stress.
Although they aren't positive why, the researcher have found a link between lower risks of depression and the consumption of 4 cups or more of green tea a day. They are looking to do another study to further examine whether or not the theanine is the spark that may be effective in the treatment and prevention of depression symptoms in again patients.
Until then keep drinking green tea, because it has a lot of other health benefits that we often talk about.
Because, Looking and feeling Old is Optional.