Defending Against Cancer
Vegetables deliver a great array of salutary substances, such as various flavanoids, vitamins and minerals that are vital to basic health
Know Your Grocery
The substances in plant produce that account for the health benefits are sometimes called phytochemicals. One system that employs phytochemicals most extensively is Traditional Chinese Medicine (TCM). However, some regular grocery items can be surprisingly full of them: grapes, strawberries, olives, watercress, coriander, or even onions and soy beans are some common providers. Dr George Ku, who has previously worked as a pharmaceutical developer for over 20 years in the US and the holder of a long list of patents, and who has in recent years become an advocate for natural therapies, pinpoints three types of food products which cancer preventive phytochemicals can be effectively obtained in the diet (11):
- Cruciferous vegetables such as bok choi, cabbage, broccoli etc for the phytochemical indole-3-carbinol
- Turmeric, the intensely yellow ginger used in curry powder, for curcumin
- Green tea for tea catechins, in particular epigallocatechin-3-gallate —EGCG
There are actually a few substances from different categories of tea that can be contributive to cancer prevention (12), but since tea and its constituents are naturally existing materials which pharmaceutical companies cannot claim patents of, not a lot of resources have been put into more researches for better understanding and usage of them. A video of interest in the popular TED Talk program, Dr William Li of the Angiogenesis Foundation presents the fact that even the most effect drugs for cancer compare only marginally with substances in our normal grocers (13).
We present in this article here whatever is found by the science community, and hope more enlightening studies will come by. Most of the cancer and tea studies now focus in catechins and some touch on theaflavins, a group of flavonoids transformed from catechins.
Substances in Tea
EGCG — epigallocatechin 3-gallate — one of green tea’s catechins, is a most powerful antioxidant
Tea catechins are the majority of substances inside the fresh tealeaves, besides, of course, water and cellular structural materials (which some scholars refer to as ashes). They can be 15 to 30% of the dried weight of the leaf. Of all the catechins, EGCG, a somewhat bitter and white (colourless when dissolved in water) material, is most studied for its outstanding anti-carcinogenic potential.
Catechins exist in almost all categories of tea when they are freshly produced. Green and white teas hold the most of them. Some quantity of the catechins is transformed into other substances during production processing for oolongs, more so in black and dark teas. Some of these transformed substances are also of unique health nature, some are also taste and aroma materials. Examples of health interests are gallic acid, theaflavins, and some other forms of flavonoids.
It is also important to note that in addition to catechins and the above mentioned, other substances in tea such as theanine (a unique amino acid in tea), caffeine, vitamins, essential oils and minerals are also part of the package that delivers the synergic health effects of tea.
Catechins are fragile materials that can degenerate upon excessive contact with light, heat, humidity, oxygen and other foreign matters. Excessive processing, poor quality, and non-protective packaging result in the loss of catechins, and for that matter most substances in the tealeaves that contribute to tea’s health and taste qualities. The difference between a better quality whole leaf tea and a mass market product can be extremely dramatic. We have discussed that in various articles in this site and will not repeat here. Make your choice wisely.
