Tea
Written by Tommy Li and Jerry Lau
Tea was and still is one of the most highly sought after commodities in the world. From its origins in a small province in ancient China, to its massive rise as a huge motivator in world conflicts, tea has been anything but a drink. But why tea? Tea has been used around the world for its perceived medicinal qualities, its rich taste, its ability to bring people together, etc. Here we will focus on tea’s perceived medicinal qualities and weigh out how the health claims on tea hold out versus the scientific community.
Teas’ health claims range from the relatively benign claim of improving blood pressure and circulation to eye-raising claims of being able to fight various forms of cancer (3). However most studies state that these health benefits come from drinking tea over long periods of time and do not paint tea as a “miracle substance” that many from the tea industry characterize it to be. How does tea have these benefits? There are substances in tea called polyphenols, more specifically catechins and epicatechins. Lab and animal studies find that these molecules have anti-inflammatory and antioxidant properties (1). This is corroborated by multiple studies in the field; one such study stating that patients with elevated blood pressure or hypertension would benefit from regular tea intake which was shown to have positive effects on the patients’ blood pressure (2).
There are many different types of tea available to purchase; some popular ones being black tea, green tea, oolong tea, and Kombucha. Although all teas contain polyphenols, not all teas are made equal. For example, Kombucha, a probiotic-rich fermented drink made with tea (green or black), sugar, bacteria, and yeast, is very interesting. Kombucha has a yeast component that usually includes Saccharomyces and other species; the bacterial component almost always includes Gluconacetobacter xylinus. It can be a fermented slightly effervescent, sweetened (slightly sour) drink used as a functional beverage to provide health benefits (0.5-3% alcohol). Microbes break sugars down to alcohol and CO2. Then bacteria converts alcohol to acids (e.g. acetic). It has been traditionally used primarily in Manchuria, Russia, eastern Europe and Japan. Kombucha claims to have benefits to asthma, cataracts, diabetes, diarrhea, gout, herpes, insomnia and rheumatism; to shrink the prostate, raise the libido, reverse grey hair, remove wrinkles, relieve hemorrhoids, lower hypertension, prevent cancer, to promote general well-being, help to lose weight, treat constipation, and to stimulate the immune system (4). But because of its microbial sourcing and possible non-sterile packaging, it is not recommended for people with poor immune function (HIV), women who are pregnant or nursing, and children under 4 years old. Furthermore, matcha, a type of green tea, is very effective in reducing stress. Beside caffeine, it also contains theanine, a major amino acid in green tea that exhibits a stress-reducing effect in mice and humans (5).
The potentials of tea have been analyzed in many experiments. Further research will be needed to investigate more benefits and side effects. Given the tremendous amount of time in history, people have learned to appreciate tea - a taste of age.
References:
Zhang Z, Feng X, Wang Y, et al. Advances in research on functional genes of tea plants. Gene. 2019;711:143940.
Mahdavi-Roshan M, Salari A, Ghorbani Z, Ashouri A. The effects of regular consumption of green or black tea beverages on blood pressure in those with elevated blood pressure or hypertension: A systematic review and meta-analysis. Complement Ther Med. 2020;51:102430.
“The Hidden Health Benefits of Tea”. Health and Wellness. PennMedicine. https://www.pennmedicine.org/updates/blogs/health-and-wellness/2019/december/health-benefits-of-tea. Accessed 2021 Aug 26.
Beaufort, S, Bouajila, J, Taillandier, P. “Understanding Kombucha Tea Fermentation: A Review”. https://pubmed-ncbi-nlm-nih-gov.jerome.stjohns.edu/29508944/ 2018 Mar;83(3):580-588.
Unno K, Furushima D, Hamamoto S, Iguchi K, Yamada H, Morita A, et al. . Stress-reducing function of matcha green tea in animal experiments and clinical trials. Nutrients. (2018) 10:1468. 10.3390/nu10101468
Green tea, extracted from Camellia sinensis leaves, has been revered for centuries for its refreshing taste and presumed health advantages. Traditional Chinese and Indian medicines acknowledge its therapeutic properties, and contemporary studies continue to unveil its potential in pharmacology. A prominent constituent of green tea is catechins, antioxidants that may safeguard cells against harm. Among these, epigallocatechin gallate (EGCG) stands out for its potent antioxidant properties. Antioxidants neutralize harmful free radicals, thereby reducing oxidative stress and inflammation, both of which are linked to various chronic ailments.
The medicinal benefits of green tea are manifold, including potential protection against cardiovascular disease. Research suggests that green tea consumption may decrease LDL cholesterol levels and diminish the risk of heart disease. Catechins in green tea may also enhance endothelial function, which helps regulate blood pressure and clotting, further supporting heart health. Green tea has been linked to a reduced risk of certain cancers. Studies indicate that EGCG may impede tumor growth and prevent cancer cell proliferation, particularly in breast, prostate, and colorectal cancers. Although further research is needed to fully comprehend the mechanisms, green tea's anti-cancer properties show promise. Green tea is also associated with weight management and metabolic health benefits. Some studies suggest that catechins can boost energy expenditure and fat oxidation, leading to weight and body fat reduction. Green tea extract supplements are sometimes used as a natural weight loss aid. Another area of interest is green tea's potential to protect the brain. Some studies suggest that catechins may shield brain cells from damage and reduce the risk of neurodegenerative diseases like Alzheimer's and Parkinson's. Green tea consumption has also been linked to improved cognitive function and reduced cognitive decline in older adults. Green tea catechins can interact with various enzymes and signaling pathways in the body. For example, EGCG can inhibit the activity of catechol-O-methyltransferase (COMT), an enzyme that breaks down neurotransmitters like dopamine, potentially affecting mood and cognition.
Green tea also contains caffeine, albeit in smaller amounts than coffee. Caffeine is a stimulant that can enhance alertness, concentration, and mood. The combination of caffeine and catechins in green tea may synergistically boost brain function, contributing to its reputation as a "brain-boosting" beverage.
In conclusion, green tea offers a wide range of potential health benefits, supported by both traditional knowledge and modern research. Its abundant antioxidants, particularly EGCG, contribute to its medicinal properties, which include cardiovascular protection, cancer prevention, weight management, and neuroprotection. While more research is needed to fully understand the mechanisms and optimize its therapeutic use, incorporating green tea into a balanced diet may offer numerous health advantages.
References:
https://www.nccih.nih.gov/health/green-tea#:~:text=Tea%20has%20been%20used%20for,headaches%2C%20and%20promoting%20weight%20loss.
https://www.mskcc.org/cancer-care/integrative-medicine/herbs/green-tea
The Benefits of Epigallocatechin Gallate from Green Tea
Many studies explore the potential health benefits of Epigallocatechin gallate (EGCG), a polyphenol found in green tea, specifically for its anti-cancer effects and protective properties against neurodegenerative diseases. However, its limited bioavailability after oral administration hinders its use in medication, relegating it to dietary supplements like green tea extract. The need for further modifications is emphasized to make EGCG suitable for widespread medical applications.
Numerous studies have investigated the correlation between tea consumption and health benefits, with green tea being associated with a reduction in various cancers. While more evidence is required to confirm these findings, EGCG has demonstrated anti-cancer effects on various cancer cells in vitro and protective properties against neurodegenerative diseases like Alzheimer's and Parkinson's.
In biological studies, EGCG has shown anti-tumor activity against a wide range of cancers, inhibiting growth, adhesion, migration, invasion, metastasis, and angiogenesis. Its antioxidant potential and molecular properties enable the regulation of gene expression and signaling pathways, influencing the immunological system against tumors and reducing the accumulation of abnormal proteins during cellular aging.
Various studies have explored the relationship between EGCG and breast cancer. EGCG acts on breast cancer cells by inhibiting signaling pathways, resulting in cell cycle arrest and apoptosis. Derivatives of EGCG have been synthesized to improve stability and solubility, but despite enhanced physicochemical properties, their biological activity did not significantly differ from basic EGCG. Other studies explored novel derivatives with potential anti-metastatic activity and inhibition of urokinase plasminogen activator, a biomarker associated with high metastasis risk.
Research on molecular mechanisms revealed that certain derivatives, like peracetylated EGCG, significantly inhibited proteasomal activity, induced apoptosis, and inhibited tumor growth in breast cancer models. These derivatives also demonstrated efficacy in reducing neuropathic pain.
In addition to breast cancer, EGCG derivatives showed effectiveness against other female-specific neoplastic diseases, such as endometriosis and uterine fibroids. Studies indicated their anti-angiogenic, anti-oxidative, and growth-inhibiting capacities without affecting ovarian follicles and uterine endometrial glands.
EGCG's antimicrobial effects, particularly against viruses, have been explored, with potential relevance in the context of the COVID-19 pandemic. In terms of antiviral and antimicrobial activities, EGCG derivatives have demonstrated potent effects against a range of viruses. Acyl derivatives of the chemical structure exhibit high antiviral, antibacterial, and antifungal activities. Additionally, EGCG conjugation with chitooligosaccharides and chitosan enhances antimicrobial activity, potentially extending the shelf life of perishable foods.
EGCG's antioxidant properties are well-documented, attributed to its ability to scavenge free radicals, chelate metal ions, and inhibit certain enzymes. Derivatives with non-polar moieties display improved antioxidant activity. Similarly, theaflavins, with structural similarities to EGCG, demonstrate superior antioxidant capabilities in specific aspects.
In terms of anti-allergic and anti-inflammatory activities, EGCG and its derivatives show promise. Certain derivatives exhibit potential in suppressing histamine release contributing to anti-allergic effects. Furthermore, EGCG and its derivatives exhibit anti-inflammatory effects by modulating TNF-α and NF-κB signaling pathways, which is important in preventing chronic diseases associated with inflammation.
Despite these promising findings, challenges related to the stability and metabolism of EGCG, particularly during prolonged storage and exposure to gastrointestinal conditions, need to be addressed. Future research directions may focus on optimizing formulations, exploring EGCG as a carrier for other active substances, and developing pharmaceutical nanoformulations to overcome limitations related to physicochemical properties.
References:
A. Kumagai, Y. Nagaoka, T. Obayashi, Y. Terashima, H. Tokuda, Y. Hara, T. Mukainaka, H. Nishino, H. Kuwajima, S. Uesato Tumor chemopreventive activity of 3- O -acylated (−)-epigallocatechins Bioorg. Med. Chem., 11 (2003), pp. 5143-5148
A.T. Reddy, S.P. Lakshmi, E. Maruthi Prasad, N.Ch Varadacharyulu, L.D. Kodidhela Epigallocatechin gallate suppresses inflammation in human coronary artery endothelial cells by inhibiting NF-κB Life Sci., 258 (2020), Article 118136
Bakun P, Mlynarczyk DT, Koczorowski T, Cerbin-Koczorowska M, Piwowarczyk L, Kolasiński E, Stawny M, Kuźmińska J, Jelińska A, Goslinski T. Tea-break with epigallocatechin gallate derivatives - Powerful polyphenols of great potential for medicine. Eur J Med Chem. 2023 Dec 5;261:115820
L. Zan, Q. Chen, L. Zhang, X. Li Epigallocatechin gallate (EGCG) suppresses growth and tumorigenicity in breast cancer cells by downregulation of miR-25 Bioengineered, 10 (2019), pp. 374-382
S. Zhu, Y. Li, Z. Li, C. Ma, Z. Lou, W. Yokoyama, H. Wang Lipase-catalyzed synthesis of acetylated EGCG and antioxidant properties of the acetylated derivatives Food Res. Int., 56 (2014), pp. 279-286
The rise of bubble tea in western society has provoked inquiries about its health benefits and side effects from daily consumption. Bubble tea also known as “boba,” “tapioca pearls,” or “pearls,” is a popular tea originated from East Asia, specifically in Tainan and Taichung in 1980. Bubble milk tea is made from cassava seeds and contains sweeteners, milk, various toppings, flavorings, and ice. The popular tapioca pearls, usually made from starch, contain high levels of carbohydrates and depending on the flavors have various high-fructose corn syrup, and surgery fruit concentrates. This drink has become widely purchased by all ages and daily consumption of a high caloric drink raises the question of obesity risk and if there are any nutritional benefits.
The tapioca pearls are mixed with all types of teas- black, green, oolong- which have nutritional value but is misleading due to the high sugar content. While the tea itself are rich in nutrients and in their history, the additional sweeteners reduce the nutritious calories. The chewy consistency makes the pearls have an addicting taste. In addition, the high amount of fructose found in sugar-sweetened beverages increases the feeling of hunger. This will cause leptin resistance which is the hormone responsible for signaling satiety. This trendy drink is another one to add to the list of sugary drinks with high sugar content.
The sugar-sweetened beverage may contribute to the rise of obesity, risk of type 2 diabetes mellitus, and cardiovascular diseases. The cassava balls dipped in brown sugar are ingredients that stimulate high blood sugar levels. It may also cause painful stomach problems in any individual but especially in the elderly. Too much of anything is not good but in this case, it is especially detrimental when we are not sure of all the contents in the drink. Overall, it is important to be weary of what we consume especially if it’s on a daily basis.
References:
What’s In your boba? | the public health advocate. What’s in Your Boba? (n.d.). https://pha.berkeley.edu/2017/12/03/whats-in-your-boba/
Zubairi, S. I., Kasim, Z. M., Zahiri, M. H. A. M., & Huda-Faujan, N. (2023, August 30). Health concern of phenomenally premium boba milk tea and pearls beverages in Kuala Lumpur: Sugary content and Physico-chemical profiles analysis. Current Research in Nutrition and Food Science Journal. https://www.foodandnutritionjournal.org/volume11number2/health-concern-of-phenomenally-premium-boba-milk-tea-and-pearls-beverages-in-kuala-lumpur-sugary-content-and-physico-chemical-profiles-analysis/
Tea:
Written by: Hillary Pham and Jae Chang
Tea is a drink that is loved by so many all around the world. Many can enjoy this tea drink in numerous, different ways, whether that can be hot or cold. There is also a wide range of teas; like black tea, chamomile tea, green tea, oolong tea and still so much more! And over the years, many people have curated creative tea drinks that are loved by so many. Nevertheless, there are still a lot of people who haven't recognized that tea is an excellent source of supplements to receive great health benefits from.
In Asia, tea is the second most consumed beverage besides water. Tea is proven to be a rich source of pharmacologically active molecules that provide great health benefits. An example of the beneficial pharmacologically active molecules in tea is polyphenols. They constitute the majority of active compounds in teas and exist as catechins. The types of catechins in teas include EGCG, epigallocatechin, epicatechin-3-gallate and epicatechin, gallocatechins and gallocatechin gallate. In black tea, other forms of polyphenolic compounds exist including theaflavins and thearubigins.
Matcha tea originally derived from Japan is a type of powdered green tea. Although they are quite similar, many tend to confuse green tea with matcha tea. Green tea uses brewed tea leaves to produce the so-loved green tea drink. On the other hand, matcha is actually the pulverized version of the green tea leaves. By pulverizing the green tea leaves beforehand, it produces an even stronger concentration of the green tea allowing for even more nutrients and benefits to be extracted. It is evident that the process of making matcha green tea is a lot more strenuous as compared to the brewed green tea. This is because during the growth period of the matcha green tea, it is necessary to shade the plants since it enhances the flavor and taste of the tea. It can additionally, provide all the health benefits of the tea as it will contain chemical compounds like caffeine, chlorophyll, and catechins. Through its entire process, matcha green tea is considered as the highest quality tea due to its laborious extraction, purified form, and chemical components.
Besides the taste and the flavor of the green tea, the health benefits of matcha green tea are why it is also so loved by many. Matcha green tea has high levels of antioxidants as well as anti-inflammatory compositions. The high levels of antioxidants are attributed to the catechin content found in the green tea. Some clinical researchers believe that regular consumption of matcha green tea can prevent diseases and “may have a positive effect on both physical and mental health” (Kochman et. al). Many research have demonstrated using cell culture and animal studies that tea polyphenols like catechins have beneficial effect on diseases such as cancer, diabetes, and cardiovascular diseases.
In contrast to matcha tea, the beverage of tea that holds the spot for the world’s highest tea consumption is black tea. It is followed by green tea, oolong tea, and white tea. Black tea is consumed usually in US, Europe, Africa, and India and is processed by crushing and drying the tea leaves to effect fermentation. As stated previously, teas have antioxidant properties; however, it also contains traces of proteins, carbohydrates, amino acids, lipids, vitamins, and minerals. Within it, the polyphenols give unique tea aroma as well as its health benefits. The number of polyphenols is highest in green tea than black or oolong tea, and therefore green tea has the most amount of antioxidant properties. Among the catechin found in teas, EGCG is the chemical that has been the most studied in green teas. Studies show a cup of green tea has 200 mg of ECG which is also seen to have chemo-preventive and chemotherapeutic effects against many types of cancers. The recommended daily consumption for green tea is around three to five cups a day which provides around 250 mg of catechins. Unfortunately, despite the many beneficial effects of EGCG, this compound has low bioavailability when consumed orally, and developing methods to deliver EGCG to the target areas has proven to be a significant challenge.
Teas are one of the most popular beverages in the world. It contains chemicals that provide a range of beneficial health effects. One of the catechins found in teas is EGCG and it modulates some signal transduction pathways and has chemotherapeutic effects. However, it is important to note that some molecules involved in signaling pathway may be affected by EGCG and in reverse cause chronic disease like cancer. Ultimately, while teas have some health benefits including anti-inflammatory effects, further clinical evidence and stronger proof is required to accurately determine the mechanisms of cancer prevention by tea in people.
References:
Kochman, J., Jakubczyk, K., Antoniewicz, J., Mruk, H., & Janda, K. (2021). Health benefits and chemical composition of matcha green tea: A review. Molecules, 26(1), 85.
Khan, N., & Mukhtar, H. (2018). Tea Polyphenols in Promotion of Human Health. Nutrients, 11(1), 39. https://doi.org/10.3390/nu11010039