estimatedthat major depressive disorders affect 21 million adults in the United States.
- Researchers in Japan say that matcha tea powder may be able to help ease depression as well as boost mood and mental performance.
- They say the powder boosts mental health by activating dopaminergic neural circuits.
- Their study was done on mice and experts say more research on human subjects is needed.
Researchers said their findings showed the traditional Japanese tea can help boost mood and mental performance by activating dopaminergic neural networks and improving depressive symptoms in mice that previously experienced stress from social isolation.
Matcha has been touted for its health benefits. However, according to researchers from Japan’s Kumamoto University, more mechanistic research is required, which is why the study was done on mice. They said further research could help develop better antidepressants.
The researchers pointed out that depression is the most prevalent mental health condition in the world and the number of people affected by it continues to grow.
Although its onset varies, it’s believed to come from reduced dopamine in the brain. Dopamine is a neurotransmitter and hormone playing an important role in elevating one’s mood.
Antidepressants can counter low dopamine, but many have side effects. People can also develop resistance to antidepressants, requiring higher doses or changes in medication.
Traditionally used in tea, matcha comes from the leaves of Camellia sinensis, which are rich in mood-boosting compounds.
Researchers say regular matcha consumption in mice during previous studies has improved anxiety-like behavior in the lab animals by activating dopamine function via dopamine D1 receptor signaling.
Dr. Yuki Kurauchi of Kumamoto University led a team of researchers to investigate the effects of matcha tea powder on depression in socially isolated mice.
The team used stress-tolerant BALB/c and stress-susceptible C57BL/6J mice it subjected to social isolation stress.
They said orally administering a matcha tea suspension appeared to reduce levels of depression in the stress-susceptible mice. This was measured by the mice’s performance in tail suspension tests, which are commonly used to evaluate depression in mice.
“Matcha tea reduced the immobility time only in stress-susceptible mice that experienced greater stress from social isolation and exhibited higher depression-like behavior, in comparison to the stress-tolerant mice.” Kurauchi said in a statement.
An analysis of the mice brains revealed activation of the prefrontal cortex and nucleus accumbens in the stress-susceptible mice after they consumed matcha. These regions form an important part of the dopaminergic circuit and are crucial for controlling dopamine levels in the brain.
Their activation — indicated by an increase in the number of cells expression c-Fos, an important indicator of neural activity—would typically boost dopamine levels, elevating one’s mood.
Experts told Healthline they were optimistic about the study but pointed out there are differences between mice and humans.
“There is limited information about whether matcha can affect depression in humans and the optimal dose and duration of use of matcha to prevent or treat depression has not been established,” said Dr. Kelly Johnson-Arbor, a medical toxicology physician and medical director at National Capital Poison Center.
“For now, it’s unclear whether matcha is effective in altering moods in humans.” Johnson-Arbor told Healthline. “While most healthy individuals may be able to incorporate matcha tea into their daily routine as part of a healthy, balanced diet, it’s important to remember that matcha has not been conclusively proven as effective in affecting the development of depression in humans.”
“People should always check with their doctor prior to using matcha, or any other natural remedy, to manage symptoms of depression,” she added.
Victoria Chan, a licensed naturopathic doctor specializing in integrative mental health and medically trained in pharmaceuticals, told Healthline that matcha contains high concentrations of L-theanine, an amino acid that calms the brain and nervous system. This also reduces the jittery effects of the tea’s natural caffeine.
“The scientific community is constantly learning more about why depression develops,” Chan said. “Unlike popular misconceptions, depression is not solely caused by unbalanced neurotransmitters or ‘chemical imbalances.’ Depression can be caused by dysfunctions in digestion, hormones, immune responses, thyroid, detoxification, allergic responses, nutrition, liver, genetics, stress responses, amongst many other factors.”
Chan said matcha lessens depression in ways beyond affecting neurotransmitters.
“If your antidepressant medication is not relieving your depression, you may have a root cause that isn’t fully dictated by neurotransmitters – which antidepressant pharmaceuticals mostly affect,” Chan said. “If this is the case, you could benefit from treating your depression through other biological pathways and using tools that help those different pathways like how matcha does.”
Dr. Zeeshan Afzal, a dermatologist and medical officer for AI healthcare platform Welzo, told Healthline that matcha’s L-theanine and caffeine can combine to improve brain function.
However, Afzal also cautioned not to get too enthusiastic yet.
“While the study done on mice may provide some insights into the potential antidepressant,” Afzal said. “It’s important to note that the results may not necessarily translate to humans. Mice and humans have different physiologies and there are often significant differences in how drugs and treatments affect the two species.”
Afzal said more affective human studies are necessary.
“If future studies confirm the antidepressant effects of matcha, it could potentially become a natural alternative or complementary treatment for depression,” he said. “However, it is important to note that there is still much research to be done in this area, and people with depression should always seek the guidance of a qualified healthcare professional for diagnosis and treatment.”