Green tea has been consumed and hailed for its health benefits for centuries around the world. All teas, except the herbal varieties, are brewed from the dried leaves of the Camellia sinensis bush. Green tea is made from the un-oxidised leaves and is one of the least processed forms of tea. It therefore contains a higher level of antioxidants and beneficial polyphenols. It accounts for only about 20% of the total tea consumption.
Green tea was used in traditional Chinese and Indian medicine to heal wounds and control bleeding, to aid digestion, to regulate body temperature and to improve heart and mental health. Nowadays studies have suggested that the positive effects can range from weight loss to helping type 2 diabetes, liver disorders and Alzheimer’s disease. But it is important to note that more evidence is required before these possible health benefits are proved definitive.
Possible health benefits of green tea
- Cancer – The polyphenols in tea have been shown to decrease tumour growth in animal and laboratory studies according to the National Cancer Institute in the US. Researchers believe these high polyphenol levels help kill cancerous cells and stop them from growing. But the amount of tea required for cancer preventative effects has varied widely in studies from 2 to 10 cups a day. We will also take a look at the possible benefits of matcha tea which is powdered green tea in which the whole leaves are consumed thus increasing the concentration of the possible beneficial ingredients.
- Lowering Cholesterol – Studies have found that consuming green tea have lead to a modest but significant reduction in LDL or bad cholesterol. However the quantities required suggest that 4 cups or less have no effect.
- Heart Disease – A study in 2006 which followed over 40,000 Japanese participants between the ages of 40 and 79 for 11 years concluded that green tea consumption is associated with reduced mortality due to all causes including cardiovascular disease. The participants who drank at least 5 cups a day had a significantly lower risk of dying than those who drank less than one cup per day.
- Weight Loss – Studies have been inconclusive in this area so more research is needed.
- Reducing Risk of Stroke – A study published in the journal Stroke: Journal of the American Heart Association, found that adding daily green tea and coffee to your daily diet helped lower the risk of stroke.
- Alzheimer’s Disease – Various studies have looked at molecules in green tea which could protect cells from the toxic effects of the protein amyloid-beta.
- Type 2 Diabetes – Once again the relationship between green tea and diabetes has produced inconsistent results in studies carried out so far.
- Working Memory – Research published in the journal Psychopharmacology in 2014 suggests that green tea can enhance our brain’s cognitive functions particularly the working memory.
- Inflammatory Skin Diseases – A study in 2007 concluded that green tea could help treat skin disorders such as dandruff and psoriasis.
- Rheumatoid Arthritis – A new study has found that a compound in green tea could be an effective treatment for RA.
There are few side effects for adults of drinking green tea but those taking anticoagulant drugs such as warfarin should drink it with caution due to its vitamin K content.
Matcha is a powdered form of green tea and one cup delivers the equivalent antioxidant power of 10 cups of green tea. It is also said to have approximately 15 times the amount of antioxidants as blueberries or pomegranates. There have been few studies on the health benefits of matcha but it can be assumed that the possible benefits of green tea would be obtained from matcha as well.