Alberta Cancer Foundation

Green Tea: Healer or Hype?

Genmaicha, Jasmine, Gunpowder, Yerba Mate. All of these names have one thing in common – they are all varieties of green tea. Walk down the supermarket aisle and you will be amazed at how many varieties of tea are available. This is no surprise when you consider how important it is in many cultures and is second only to water in worldwide popularity as a beverage.

Many cultures already believe in the healing powers of green tea. It offers protection against cardiovascular disease and kidney stones, helps strengthen bones and teeth, as well as boosts the immune system. Researchers have also been busy trying to form concrete evidence to support green tea and its role in cancer prevention.

There is no evidence green tea fights cancer in humans, but studies have shown promising results for the drink. Inside that tea bag, green tea is rich in catechins (also known as flavanoids), which act as powerful antioxidants in the body. One cup of green tea has 30 to 40 per cent catechins. This compared to the only three to 10 per cent found in black teas. The strongest catechin associated with cancer-preventing properties and most heavily researched is epigallocatchin gallate (or EGCG). Many studies have found that green tea and EGCG can inhibit tumour growth from occurring as well as decrease the amount of times tumour cells will multiply during all stages of cancer development.

While the evidence does appear promising, most studies have looked at animals or isolated human cancer cells. Few studies have involved humans, and the ones that have are often mixed or less conclusive. This may be that the amount of EGCG given to most animals is higher than most individuals would normally choose to drink (greater than six cups per day). It is also difficult to draw conclusions in human studies because of different genetics, lifestyle factors and tea consumption among individuals. Some of the more promising studies to date, however, have shown that individuals who drank two or more cups of green tea a day had lower incidences of both prostate and ovarian cancer than those who were not tea drinkers.

A recent study found green tea may interfere with some cancer drugs. Please talk to your doctor about any herbal remedies you take. This is no reason to throw out your tea bags just yet. There are still benefits to including tea into your daily routine. Without sugar, honey or milk, tea is still a great zero-calorie beverage choice. It can also be a great comfort during those bone-chilling winter days or a quick pick-me-up mid-afternoon.


Tania Vander Meulen is a private practice dietician working out of Kensington Physical Therapy and Dynamic Sports Physiotherapy.