7th in series of 20 

Most People Believe that Drinking Tea Helps Prevent and Fight Disease

 Perhaps the benefit to this being part of our ancient oral healing tradition has infused it so deeply into our belief system, that there seems to be little dispute. Or it may be because we tend to feel better when we drink tea. And when we share tea. And for decades now, modern medical research has invested heavily in studies to determine how Camellia sinensis actually benefits our health. The experience of tea as a medicine can now be observed on a cellular level and understood in terms of specific diseases and unhealthful consitions.

What's Healthy About Tea graphic

To be very clear, no one selling tea can use any of the results of medical research to promote their products. But, when you look at a list like this and consider the decades of research and centuries of belief in the benefits of drinking tea, it is not surprising that increasing numbers of research projects are setting up laboratory conditions and also studying habitual tea drinkers to better understand and document the oral history. But the US FDA and other international counterparts continue to restrict sharing health claims in retail settings.

In this 7th article in the series we will take a quick overview of some of the diseases that are being studied to see how tea helps prevent and fight some very diverse and complex conditions.


Some of the most abundant research into the health benefits of tea relates to cancer. Many studies over the last 15 years are building a body of data that re applicable to cancer in general and to some specific forms of cancer. These include cancers of the bladder, breast lungs, ovaries, colon, kidney, esophagus, pancreas, prostate, and skin. Almost all research uses green tea rather than other kinds of tea. There are studies in both human consumption studies and also clinical trials using tea extracts. Studies in controlled laboratory studies tend to show more beneficial results. This tends to be because there are so many lifestyle variables that impact the efficacy of tea as a daily practice. But significant numbers of studies show that Camellia sinensis does offer benefits.

We have studied cancer prevention with green tea for over 30 years, and our collaborations have produced numerous significant results, both from basic studies and with cancer patients and the general human population (Fujiki et al., 20022012). 

Cancer Prevention with Green Tea and Its Principal Constituent, EGCG: from Early Investigations to Current Focus on Human Cancer Stem Cells    Hirota Fujiki,1,* Tatsuro Watanabe,1 Eisaburo Sueoka,1 Anchalee Rawangkan,2 and Masami Suganuma2

Heart Disease

Studies have shown that habitual tea drinkers with a long-term daily practice (at least three cups/day) have a reduced risk of heart disease and stroke. It is observed that they have improved function of blood vessels, better circulation, and healthier cholesterol levels.

One Taiwanese study on more than 1500 subjects who consumed between 2 – 3 cups of tea/day, showed that a 65% reduction in developing high blood pressure. 

2002 Harvard study followed 1900 heart attack patients. They reported a significant increase in the survival rate of those who were regular tea drinkers vs. non-tea-drinkers. 


Our findings suggest that ingestion of black tea with food containing sugar is beneficial in glycemic control and diabetic prevention.

From: Black tea consumption improves postprandial glycemic control in normal and pre-diabetic subjects by Arisa Butacnum MSc, Rewadee Chongsuwat PhD, Akkarach Bumrungpert PhD published in Asia Pacific Journal of Clinical Nutrition

Neurological Diseases 

Some of the most interesting and promising studies into tea and health are related to neurological function. This includes dementia, Parkinson’s, Huntington’s, and muscular dystrophy. 

According to the documents, green tea exhibits antidepressant, anti-neurodegenerative (e.g., anti-Parkinson and anti-Alzheimer), as well as neuroprotective effects.     From: Green Tea, A Medicinal Food with Promising Neurological Benefits.  by Hossein Akbarialiabad 1Mohammad Dahri Dahroud 2Mohammad M Khazaei 2Saeed Razmeh 3Mohammad M Zarshenas 1 

Green tea polyphenols are now being considered as therapeutic agents in well-controlled epidemiological studies, aimed to alter brain aging processes and to serve as possible neuroprotective agents in progressive neurodegenerative disorders such as Parkinson’s and Alzheimer’s diseases.   

From: Neurological mechanisms of green tea polyphenols in Alzheimer’s and Parkinson’s diseases.  by Orly Weinreb 1Silvia MandelTamar AmitMoussa B H Youdim

Weight Management

Weight loss with tea is a hot topic and an often abused marketing strategy. No evidence drinking tea alone will result in measurable weight loss. A more responsible discussion for using tea to shed pounds is to include it in a more comprehensive program for maintaining healthy body weight. That being said, drinking tea does help to speed up metabolism, helps the body recover after exercise, and is a very effective replacement for high-calorie beverages sweetened with sugar.

Fighting Super-Bugs That Resist Antibiotics

Antibiotic-resistant bacteria continue to threaten global health. Researchers continue searching for chemical solutions, but a 2018 study concludes that a compound found in green tea might increase the efficacy of existing antibiotic drugs.

The most recent study looking for ways to solve the antibiotic resistance crisis investigated green tea. The authors of the study conclude that one particular compound in green tea might bolster failing antibiotics and help them to kill bacteria more efficiently.  By the scientists, from the University of Surrey School of Veterinary Medicine in Guildford, United Kingdom, focused on the bacterium Pseudomonas aeruginosa.  Read Article in Medical News Today by by Lisa Templeton on October 6, 2019 

Attention Deficit Disorders 

Tea is a kind of stimulant and many adults like to drink it. The caffeine in tea can reduce one’s fatigue, increase people’s self-confidence, motivation, alertness, vigilance, efficiency, concentration, and cognitive performance. This report proposes that tea consumption may be an effective active treatment for adult ADHD.

Tea consumption may be an effective active treatment for adult attention deficit hyperactivity disorder (ADHD) by Kezhi Liu 1Xuemei LiangWeihong Kuang

Liver Disease

Animal studies indicate that drinking several servings of tea per day as a regular habit can help protect the liver from damage by toxic substances like alcohol by reducing inflammation in the liver.

We concluded that there is a significant protective effect of green tea drinking on liver diseases. Specifically, green tea intake is associated with decreased risk of HCC, fatty liver disease, hepatitis, liver cirrhosis, and chronic disease. From: The effect of green tea intake on risk of liver disease: a meta-analysis  by Xueru Yin,1 Jiqiao Yang,2 Tony Li,3 Liyan Song,4 Tinglu Han,5 Mei Yang,1 Huihua Liao,1 Jianjun He,1 and Xiaozhu Zhong1


Measurable benefits of drinking several cups or glasses of tea on a daily basis have been found in older women but not in premenopausal women. 

Older women who drank tea had higher BMD measurements than did those who did not drink tea. Nutrients found in tea, such as flavonoids, may influence BMD. Tea drinking may protect against osteoporosis in older women.  From: Tea drinking and bone mineral density in older women   byVerona M Hegarty, Helen M May, Kay-Tee Khaw

Looking Further Into Ways that Tea Helps Prevent and Fight Disease

In the next six articles of the series, we will refer back to some of the scientific research terminology and apply it to deeper dives into the findings for ways that tea helps prevent and fight disease. We will look at several different forms of cancer, cardiovascular disease, neurological disease and dementia, diabetes, osteoporosis, and liver disease. We will consider multiple studies in each category of illness, from some of the earlier studies to newly published research.