The Health Benefits of Green Tea & Hojicha

At Ryuall, we believe that drinking green tea (Camellia sinensis) will help make you healthier!  We have compiled this informative article sourced from scholarly articles (mostly peer-reviewed research articles) to help you comprehensively learn about how green tea’s health-boosting effects on the body.

Click on each section to learn even more detail about each benefit category. Also, click here to learn about how drinking one of our teas infused with other healthy plant derivatives (butterfly pea/lemongrass, clove, hibiscus, etc.) can give provide you with even more diverse health benefits.

Antioxidant Properties:

Green tea contains polyphenols, including epigallocatechin gallate (EGCG), which act as powerful antioxidants that protect cells from damage caused by free radicals. 

Improved Heart Health:

EGCG may help lower blood pressure, reduce cholesterol levels, and prevent blood clots, reducing the risk of heart disease and stroke. 

Weight Management:

Green tea may boost metabolism and promote fat burning, potentially aiding in weight management. 

Cognitive Function:

The caffeine and L-theanine in green tea can enhance alertness, focus, and memory. 

Reduced Risk of Cancer:

Studies suggest that green tea may have anti-cancer properties, particularly against breast, prostate, and colon cancer. 

Anti-inflammatory Effects:

Green tea polyphenols have anti-inflammatory properties that may help reduce pain and swelling associated with conditions like arthritis. 

Improved Oral Health:

Green tea catechins have antibacterial and antiviral effects that may help prevent tooth decay and gum disease. 

Other Benefits:

Green tea may also:

• protect against neurodegenerative diseases such as Alzheimer’s Disease,

• improve bone health,

• reduce the risk of type 2 diabetes,

• and boost the immune system. 

How Polyphenols Act as Antioxidants that Reduce Cancer Risk

Polyphenols in green tea act as antioxidants by directly scavenging free radicals through a process called "electron donation," where they readily give up hydrogen atoms from their hydroxyl groups, neutralizing the damaging effects of reactive oxygen species (ROS) in the body, thus protecting cells from oxidative stress; they can also indirectly act as antioxidants by stimulating the production of the body's natural antioxidant enzymes. 

Key points about how green tea polyphenols function as antioxidants:

• Direct scavenging:

  
  

  The primary mechanism is the ability of polyphenols, particularly catechins like epigallocatechin gallate (EGCG), to donate hydrogen atoms to free radicals, converting them into less reactive molecules. 

  
  

• Chelating metals:

  
  

  Polyphenols can also bind to transition metals like iron and copper, preventing them from participating in harmful free radical reactions (known as metal chelation).

• Enhancing antioxidant enzyme activity:

  
  

  Studies suggest that green tea polyphenols may indirectly support antioxidant defenses by upregulating the production of enzymes like superoxide dismutase (SOD) and glutathione peroxidase. 

  
  

• Molecular structure:

  
  

  The specific chemical structure of polyphenols, with multiple hydroxyl groups on an aromatic ring, is crucial for their antioxidant activity. 

  
  

Scholarly references links:

• "Recent Advances in the Understanding of the Health Benefits and Molecular Mechanisms Associated with Green Tea Polyphenols" in Journal of Agricultural and Food Chemistry

• "Cellular Defensive Mechanisms of Tea Polyphenols: Structure-Activity Relationship" in International Journal of Molecular Science

• "Antioxidant effects of green tea" in Molecular Nutrition Food Research

How ECGC Can Improve Heart Health

Epigallocatechin gallate (EGCG), a compound found in green tea, can improve heart health by reducing blood pressure, lowering cholesterol levels, inhibiting the formation of plaque in blood vessels, and acting as an antioxidant to protect against oxidative stress, potentially reducing the risk of cardiovascular disease; these effects are achieved through mechanisms like improving endothelial function and regulating inflammation within the blood vessels. 

Key points about EGCG and heart health:

• Reduces blood pressure:

  
  

  Studies have shown EGCG can decrease both systolic and diastolic blood pressure, a significant factor in managing heart disease risk. 

  
  

• Manages cholesterol levels:

  
  

  EGCG may help lower "bad" LDL cholesterol and potentially increase "good" HDL cholesterol, contributing to better cardiovascular health. 

  
  

• Antioxidant activity:

  
  

  EGCG's antioxidant properties help combat oxidative stress which can damage blood vessel lining and contribute to plaque formation. 

  
  

• Improves endothelial function:

  
  

  EGCG can enhance the function of the endothelial cells lining blood vessels, promoting healthy blood flow and reducing inflammation. 

  
  

• Anti-inflammatory effects:

  
  

  By inhibiting inflammatory pathways, EGCG can help prevent the development of atherosclerosis, a condition where plaque builds up in arteries. 

Scholarly references links:

• "Molecular understanding of Epigallocatechin gallate (EGCG) in cardiovascular and metabolic diseases" in Journal of Ethnopharmacology.

• "EGCG, a green tea polyphenol, improves endothelial function and insulin sensitivity, reduces blood pressure, and protects against myocardial I/R injury in SHR" in American Journal of Physiology Endocrinology and Metabolism

• "EGCG, a green tea catechin, attenuates the progression of heart failure induced by the heart/muscle-specific deletion of MnSOD in mice" in Journal of Cardiology

• "Preventive Effects of Catechins on Cardiovascular Disease" in Molecules

How Green Tea Aids in Weight Loss

Green tea has been suggested to have weight loss benefits. Here are some potential mechanisms: 

• Increased Metabolism:

Green tea contains caffeine and catechins, which may stimulate metabolism and increase calorie burning. 

• Reduced Appetite:

Caffeine in green tea may suppress appetite, leading to reduced calorie intake. 

• Fat Oxidation:

Catechins in green tea may promote fat oxidation, meaning the body burns fat for energy. 

• Improved Insulin Sensitivity:

Green tea may improve insulin sensitivity, which can help regulate blood sugar levels and reduce fat storage. 

• Other Factors:

Green tea can enhance exercise performance, reduce visceral fat (fat around the organs), and promote a healthy gut microbiome. 

Scholarly references links:

• "Green tea for weight loss and weight maintenance in overweight or obese adults" in Conchrane Database of Systematic Reviews

• "The Effect of Green Tea Extract on Fat Oxidation at Rest and during Exercise: Evidence of Efficacy and Proposed Mechanisms" in Advances in Nutrition

How Green Tea Improves Cognitive Function

Green tea may improve cognitive function, including memory and executive function. Compounds in green tea, such as caffeine, theanine, and catechins, may contribute to its cognitive benefits:

• Brain activation

  
  

  Green tea extract may increase activation in the prefrontal cortex, which is involved in executive function. 

  
  

• Antioxidants

  
  

  Green tea contains catechins, which are antioxidants that may help prevent cell damage to brain neurons.

  
  

• Theanine

  
  

  Theanine may cross the blood-brain barrier and help inhibit the stimulant effects of caffeine. It may also protect the brain and improve sleep quality. 

Scholarly references links:

• "Green tea consumption and cognitive function: a cross-sectional study from the Tsurugaya Project" in The American Journal of Clinical Nutrition

• "Green tea effects on cognition, mood and human brain function: A systematic review" in Phytomedicine

• "Effects of Matcha Green Tea Powder on Cognitive Functions of Community-Dwelling Elderly Individuals" in Nutrients

How Green Tea Reduces the Risks of Cancer

Green tea may potentially reduce the risk of breast, prostate, and colon cancer primarily due to its high concentration of a compound called epigallocatechin gallate (EGCG), a powerful antioxidant that can inhibit cancer cell growth, promote apoptosis (programmed cell death), and potentially prevent the spread of tumors in laboratory studies.

Key mechanisms of action:

• Antioxidant activity:

  
  

  EGCG can neutralize harmful free radicals in the body, which can damage DNA and contribute to cancer development. 

  
  

• Cell cycle regulation:

  
  

  Studies suggest EGCG can interfere with the cell cycle, preventing cancer cells from rapidly dividing and proliferating. 

  
  

• Apoptosis induction:

  
  

  EGCG may trigger programmed cell death in cancerous cells, causing them to self-destruct. 

  
  

• Anti-inflammatory effects:

  
  

  Green tea polyphenols may have anti-inflammatory properties which could help prevent the development of tumors.

  
  

  Potential benefits to a few specific cancers

  
  

  • Breast cancer:

    
    

    Research indicates that green tea consumption may be linked to a reduced risk of breast cancer, particularly in postmenopausal women, potentially due to EGCG's ability to modulate estrogen levels. 

    
    

  • Prostate cancer:

    
    

    Studies in animal models have shown that EGCG can inhibit the growth of prostate cancer cells and may potentially help prevent prostate cancer progression. 

    
    

  • Colon cancer:

    
    

Green tea polyphenols may help prevent colon cancer by inhibiting the growth of colon cancer cells and influencing the development of precancerous lesions.

Scholarly references links:

• "Cancer and metastasis: prevention and treatment by green tea" in Cancer Metastasis Review

• "Is Green Tea Drinking Associated With a Later Onset of Breast Cancer?" in Annals of Epidemiology

• "Tea Polyphenols and Their Preventive Measures against Cancer: Current Trends and Directions" in Foods

• "Matcha green tea (MGT) inhibits the propagation of cancer stem cells (CSCs), by targeting mitochondrial metabolism, glycolysis and multiple cell signalling pathways" in Aging

How Green Tea Reduces Bodily Inflammation

Green tea has anti-inflammatory properties that may help prevent inflammation and joint pain. Green tea’s polyphenols, especially epigallocatechin-3-gallate (EGCG), have antioxidant and anti-inflammatory properties. 

How green tea reduces inflammation:

• Suppresses inflammatory genes

  
  

  EGCG reduces the expression of genes that trigger inflammation, such as COX-2, TNF-α, and MMP-1 

  
  

• Scavenges reactive oxygen species

  
  

  Green tea's antioxidant properties help reduce inflammation by neutralizing damaging molecules 

  
  

• Inhibits nuclear factor-κB activity

  
  

  Green tea reduces the activity of NF-κB, which is involved in inflammation 

  
  

• Green tea may also aid in the following specific conditions:

  • Studies have shown that green tea may help with rheumatoid arthritis

  • Green tea may also help with kidney disease

  • Green tea may help with exercise-induced changes in body composition. 

  • Green tea may help with urinary albumin-creatinine ratio in diabetic patients

Scholarly references links:

• "Impacts of Green Tea on Joint and Skeletal Muscle Health: Prospects of Translational Nutrition" in Antioxidants

• "The anti-inflammatory properties of green tea extract protect against gentamicin-induced kidney injury" in Biomedicine and Pharmacotherapy

• "Chronic Inflammatory Diseases and Green Tea Polyphenols" in Nutrients

• "Does green tea extract enhance the anti‐inflammatory effects of exercise on fat loss?" in British Journal of Clinical Pharmacology

• "Going Green: Green Tea for Rheumatoid Arthritis" on healthline.com

  
  
  
  

  

  
  

How Green Tea Improves Oral Health

Green tea can improve oral health by reducing bacteria, lowering acidity, and reducing inflammation. 

Reduces bacteria:

• Green tea's antioxidants kill bacteria 

  
  

• Green tea reduces the number of bacteria and acid in saliva and plaque 

  
  

• Green tea polyphenols reduce sulfur compounds and oral bacteria that cause bad breath 

  
  

Lowers acidity:

• Green tea lowers the acidity of saliva and plaque 

  
  

• This makes it harder for bacterial acids to attack tooth enamel 

  
  

Reduces inflammation:

• Green tea's antioxidants reduce inflammation in the body 

  
  

• This can help with gum disease, which is caused by inflammation from plaque buildup 

  
  

• This may also help reduce the risk of oral cancer 

  
  

Other oral benefits:

• Green tea can help prevent tooth decay and cavities 

  
  

• Green tea can help prevent bone loss, which maintains the strength of the dental arch and face shape 

  
  

Tips for drinking green tea:

• Drink unsweetened green tea 

  
  

• Avoid adding sweet or acidic ingredients to your green tea, such as lemon, sugar, and honey