Green Tea and Cancer
Tea is made of dried tea leaves which contain anti-cancer food compounds called catechins. Black tea (green tea that has been heat processed) has low levels of this compound, while less processed white and green teas contain much higher amounts.
Epigallocatechin gallate (EGCG) is a type of catechin, the most abundant of the catechins found in tea. EGCG has been shown to have significant anticancer properties – it stops cancer cells from dividing and also initiates cell suicide (known as apoptosis)1.
Green tea and cancer
Powerful antioxidant – green tea has strong antioxidant activity – it absorbs damaging free radicals in the blood that could trigger cancer.
Reduces risk of cancer – green tea has been shown to reduce breast cancer by 22%2, prostate cancer by 48%3 and colorectal cancer by 57%4.
Cancer progression – in order to grow beyond a certain size, tumours need access to blood vessels which provide them with oxygen and nutrients. This means that tumours have to be able to stimulate new blood vessel growth all around them (a process called angiogenesis). Green tea has been shown to interfere with a tumours ability to stimulate this blood vessel growth – thus, in theory, stopping an existing tumour from being able to grow and spread.
Additional health benefits – green tea has also been shown to have beneficial effects in Alzheimer’s disease, stroke, obesity, Parkinson’s disease and diabetes5.
How to drink green tea
Be wary of drinking green tea with milk – scientific studies have shown that cow’s milk reduces the antioxidant activity of green tea6. Many people drink green tea with soya milk, however there is a study that has shown that the combination of green tea catechins and a compound in soya milk (genistein) can actually promote cancerous growth7. There is not enough evidence, at all, to prove this association, however it would perhaps be advisable to drink green tea either on its own, or with a good quality nut or oat milk.
Drink at least 3 cups a day – it has been suggested that you need to drink a minimum of 3 cups of green tea a day, steeped for at least 5 minutes, to benefit from its ability to block cancer cell growth8.
Avoid decaf – the decaffeination process has been shown to reduce the amount of catechins present in tea9. Fortunately, green tea has about a quarter of the caffeine content of black tea, but each individual will need to determine how much caffeine they personally can tolerate. Drinking decaffeinated green tea is still better than drinking no green tea.
Favour Japanese tea – the catechin content of Japanese tea is generally higher than that of Chinese tea. Matcha and Sencha green teas both have high catechin content (of the two, Sencha has the highest concentration).
Invest in green tea powder – you can consume a greater concentration of catechins by using green tea powder, as this is made of ground tea leaves. This way you are ingesting the full leaf, as opposed to the water that the leaves have been steeped in.
Green tea has long been valued for its medicinal properties, although it is still not widely drunk in western societies. Drinking green tea or green tea powder could have substantial long term health benefits and as potent anti-cancer food should form an integral part of any anti-cancer diet.
For more detailed information on the anticancer diet, the book ‘Food to Fight Cancer: What Your Doctors Aren’t Ready to Tell You’, is available to purchase on Amazon, or at The Green Apple Club Shop.
About the author:
Sonia Nicholas is a Biomedical Scientist and Freelance Clinical Science Writer & Editor. She has been working in the field of clinical science for fifteen years.
Sonia believes that everyone can improve their health by eating a clean diet – a claim that scientific research increasingly supports. Sonia also believes that healthy, clean eating is accessible to all and doesn’t have to be an expensive lifestyle choice.
All of the information on The Green Apple Club website is in line with current, recommended Government guidelines on nutrition. All of the articles on the website are evidence based and fully scientifically referenced.
Article tags: green tea, anti-cancer diet, green tea and cancer, match green tea, anti-cancer food