Pure, Soothing, Powerful Tea since 2004

Pure, Soothing, Powerful Tea since 2004


Have you ever wondered if Sencha powder really kills cancer cells? Is the tea you are drinking a cancer-fighting tea?

The answer is YES, and we have the proof, thanks to a team of German scientists, who conducted thorough, in-depth research on our Edible Green® Sencha green tea powder with a focus on Leukemia and Multiple Myeloma cells.

The results of this just-published study are remarkable and I am excited to share them with you.

Pharmaceutical Biologists Study SEI MEE TEA Sencha

Probably you are wondering why Japanese Sencha powder sold from us located in Oregon was used in a study in Germany. It started with a gentleman who was looking for heavy metal free organic green tea. Mr. Strobel is funding ongoing research on multiple myeloma, a cancer his father succumbed to. He also believes in a whole food plant-based diet.

One day, he purchased our Sencha powder, and he suggested to Prof. Efferth at Johannes Gutenberg University in Germany that they throw the Sencha powder into his research. And one year later, the results came in. Mr. Strobel reached out to us and told us this great news.


The leader of the research group, Professor Thomas Efferth, is chair of the Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Mainz, Germany.

Both Mr. Strobel and Prof. Efferth believe in natural products or herbal medicine as a more efficient treatment against cancer than synthetic drugs. This notion is opposite to the approach of “Western School Medicine.” This research is part of their ongoing effort to reveal the truth of mother nature one step at a time.

Here are Prof. Efferth’s exact words:

“Especially for natural products, it is well known that they act on multiple targets and inhibit multiple pathways. Mother nature “invented” compounds that attack different mechanisms. For example, a plant is able to inhibit viruses and bacteria by compounds that inhibit several pathways in viruses and bacteria, not only one. This makes these compounds very efficient. In modern pharmacology, it is frequently stated that mono-specific drugs would be better because they have fewer side effects. In my opinion, this is a misconception. Because single mechanism drugs are frequently subject to resistant development. If one mechanism of action is switched off by a tumor cell (or a virus or bacteria), then the drug is not active anymore. If you have a “drug” acting against several mechanisms, switching off one mechanism does not inactivate a bioactive compound. Mother nature was smarter than mankind in this respect.”

The researchers observed results that confirm this belief. We are excited to tell you about their discoveries.

And thanks to the generosity and noble vision by this amazing research team, the whole research is shared online, so you can read this detailed study: ­­­­­­­­­“Chemo-preventive Property of Sencha Tea Extracts towards Sensitive and Multidrug-Resistant Leukemia and Multiple Myeloma Cells.”

I have to be honest with you; I am not a doctor and it was not an easy read. I needed to ask a bunch of questions. Prof. Efferth kindly sent me detailed answers. I made a summary below using the new understanding I gained from their kind correspondence! I hope it will be helpful for you too. If you would like to find more details on each section, please click the above link and read the original report.

Sencha Study

Sencha powder green tea benefits

Graphical abstract of the study

What was observed

During the research, Edible Green Sencha powder antioxidants significantly affected cancer cells and induced cell cycle arrest followed by the death of cancer cells, so-called “apoptosis.”

As you know, cancer is characterized by uncontrolled tumor cell growth and abnormal cell cycle progression. Green tea has been well studied in various types of “solid cancer,” but not in “hematologic malignancies,” such as leukemia and multiple myeloma.

 1. Introduction

The introduction is a great resource for those who would like to dig deep into the benefits of Catechin green tea antioxidants. Please visit the original report to read the scientific findings on green tea benefits.

 2. Materials and methods

Certified USDA organic sencha powder was purchased from SEI MEE TEA LLC. Sencha powder was “extracted” with 3 different solvents. However, please note that this “extract” is not the same as the “extract” available as a supplement. The professor explained to me this process is a must for the study because this process eliminates the compounds which are not pharmacologically active, such as cellulose or lignin. The extracted amount varied depending on the solvent, which is shown below under “3) Another cup, please!”

 3. Results

1) Cytotoxicity of Sencha extracts against cancer cells
They studied the effects of 3 Sencha tea and doxorubicin (a chemotherapy drug) on leukemia cells, both sensitive and resistant to the drugs. The results showed that Sencha powder tea was effective to decrease the viability of cancer cells significantly. Doxorubicin reduced viability as well; however, doxorubicin needed to be concentrated 7,758 times more to kill the drug-resistant cells. This result suggests patients will experience stronger side effects from the concentrated drug when cancer cells become resistant to the drug.

Prof. Efferth pointed out in our correspondence that Sencha powder tea required nearly the same concentrations to kill both sensitive and resistant cells. And Professor went on: This indicates that Sencha tea was not included in the resistance phenotype of the resistant cells. This means, Sencha tea was excluded from the “substance list” that tells the resistant cells which substances they need to become resistant to. Thus, Sencha tea worked for both cells.

Another remarkable fact from the study was that the viability of resistant cancer cells was still 30% even after the higher concentration of the drug, doxorubicin, was used.

The research also observed another remarkable contrast from the synthetic drug: Sencha tea differentiated between normal cells and cancerous cells, both sensitive and resistant cells. That means, no damage was done to normal cells while cancer cells died.

2) Cell Cycle Arrest

Now, the research moved on to analyze the cancer cells’ growth cycle. Great news—the cancer cells’ growth was clearly “arrested,” and was followed by the death of cancer cells, so-called “apoptosis.”

By studying molecular events in cells, scientists have determined that the phase of the cell cycle can be divided into 4 steps: Gap 0 (G0), Gap 1 (G1), S (synthesis) phase, Gap 2 (G2), and Mitosis (M phase).

They studied the effect on CCRF/CEM (leukemia) and KMS-12-BM (multiple myeloma), and Sencha tea induced G0/G1 and G2/M phase arrest followed by apoptosis.

3) Another cup, please!

The next agenda the scientists tackled was to see how the concentration would affect the apoptosis rate. They observed the efficacy for four different concentrations. The findings were that the more concentrated dose with longer exposure caused a correspondingly increase in apoptosis.

We hear this question often: how much is too much?

According to the studies I found below, the toxicity of EGCG is 800mg/day.
“Scientific opinion on the safety of green tea catechins” EFSA Journal

“The safety of green tea extract supplementation in postmenopausal women at risk for breast cancer: results of the Minnesota Green Tea Trial” Food and Chemical Toxicology

And the following study says the safe limit of EGCG is 338mg/day.
“The safety of green tea and green tea extract consumption in adults – Results of a systematic review” Regulatory Toxicology and Pharmacology
The extracted materials, pharmacologically active compounds including EGC, EGCG, ECG, GCG, and GA are shown below:

Sencha extract quantity

A ¼ tsp. powder weighs 0.5g. When you scoop “generously,” it could weigh 1g.

The above studies concluded consuming green tea as “tea” is safe while caution is needed when you take a supplement or supplement extract. It is important to clarify that the “extract” used in this study is not the same as the “supplement extract.”

Why did the scientists extract Sencha tea for the research? Prof. Efferth answered, “We used extracts of the powder. The powder still contains a lot of compounds that are not pharmacologically active (e.g. cellulose or lignin) and the powder cannot be completely solved to be taken up by cells. Therefore, we use solvents to extract the pharmacologically active compounds (such as Catechin and others).”

4) Green Tea’s pro-oxidant effect

The next research was to measure ROS, “Reactive Oxygen Species” caused by Sencha tea. ROS is frequently used as a synonym for free radicals.

Wait. Green tea is supposed to be “antioxidants”—neutralizing free radicals, not creating them!

That is true. And here’s our educational moment: “Green tea polyphenols harbor both antioxidant and pro-oxidant effects in cancer prevention,” as the research stated on page 11.

“Antioxidants” is a familiar term for a healthy diet. Thus, “pro-oxidants” are a bad guy. I was so confused by the term “potent pro-oxidants.” Why can “pro-oxidants” be “potent”?

Prof. Efferth kindly explained responding to my question: “The compounds can be ‘antioxidant’ for normal cells, but at the same time, the same compounds are pro-oxidant against ‘cancer cells.’

“Inhibition of cancer cell viability and induction of apoptosis by green tea polyphenols in vitro has been reported to result from the generation of hydrogen peroxide and superoxide anion.”

Yes, this is not a typo or mistake. Again, here’s the kind explanation by Prof. Efferth: “ROS are oxygen radical molecules, such as superoxide, hydrogen peroxide, and hydroxyl radicals. The term, free radicals, is broader and includes also radical molecules without oxygen. In many cases, both terms are used in a synonymous manner.”

And cancer cell death is the result of the generation of ROS or oxidative stress induced by Sencha. The pro-oxidant activity leads to dysfunction in the cancer cells and ultimately kills the cancer cells.

I will not repeat how they conducted the study here so please refer to the original report for the details. Most importantly, the results demonstrated that “oxidative stress” generated by Sencha extracts did induce the apoptosis of leukemia and multiple myeloma cells that they tested.

Sencha powder

5) Sencha in action in Mitochondria

The researchers observed the Edible Green Sencha powder antioxidants work “in action” at the level of Mitochondria. Mitochondria are known as “the powerhouse of the cell,” as Mitochondria are where the biochemical processes of respiration and energy production occur.

Mitochondria are the major site of production of “ROS”, reactive oxygen species. Increased ROS in mitochondria causes oxidative stress, loss of MMP, Mitochondrial membrane potential, and DNA damage in malignant cells, and finally the death of cancer cells.

Their data suggested that Edible Green Sencha powder increased the ROS generation of cancer cells, and caused mitochondrial dysfunction of cancer cells, and thus apoptosis of the cancer cell. More examinations could exactly determine how much would be the optimal amount/concentration, Prof. Efferth added in our correspondence.

6) Genetic analysis to determine which type of cancer is vulnerable

The last examination they conducted is called COMPARE and Hierarchical Cluster Analyses of Microarray Data.

The words might have just slipped over your head—for me too. So, I requested Prof. Efferth’s help to understand, and here’s the explanation. Please brace yourself, as it is quite amazing.

We talked about the uniqueness of each individual and disease. In the ideal world, it would be fabulous if you could determine which drug, and which treatment would be the best for the patient. This analysis is the foundation and beginning of the investigation. You determine the gene expression profile of the patient’s tumor. According to the expression profile, you can predict the responsiveness of cancer cells to the drug.

Prof. Efferth says, “It is certainly a long way to go to reach this goal, but proof-of-principle experiments show that this may be generally possible in principle. And if this is possible for established cancer drugs, it should also be possible for cytotoxic natural products.”

The significance of this study is the experiments show that it is indeed possible to select a set of genes and you can make a prediction of a compound’s effectiveness against a tumor based on the gene profile.


The results support the chemo-preventive properties of Edible Green Sencha Powder against hematologic malignances through multiple routes of action in vitro. Although further clarification needs to be done regarding dosage etc., this comprehensive research confirmed Sencha tea has multifactorial cytotoxicity against cancer cells while not damaging normal cells.

Current cancer treatment with chemo-drugs is the battle of chemo-drugs killing either you or cancer. The efforts to learn the mechanism of how Sencha tea powder really acts on the cancer cells like this research will lead to more discoveries about our intricate body system and will help us to harness the healing mechanisms nature has provided for us.


This article was reviewed and approved by both Prof. Efferth and Mr. Strobel. I am so grateful for their generosity because it is important for me to send you an accurate report, which was made possible thanks to the wonderful help of Prof. Efferth and Mr. Strobel.

I hope this article has boosted your confidence and knowledge in your SEI MEE TEA. Please feel free to share this good news with your friends and loved ones!

Disclaimer: The above statements have not been evaluated by the Food and Drug Administration. The efficacy of these products has not been confirmed by FDA-approved research. These products are not intended to diagnose, treat, cure or prevent any disease.

Meet the Author:  Kiyomi

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