I was diagnosed with aggresive prostate cancer 6 years ago. I started
drinking at least 4 cups of green tea a day. My prostate is almost
back to normal. Now i'm getting allergic to caffiene. Question is does
decaffinated green tea still have the polyphenals particulaly ECGC in
it?

Hello kws1~

What an interesting question! The answer is not a simple ?yes? or
?no,? however. It?s more like a ?it depends.?

As one website relates in question and answer form: 

Q: ?Does decaffeinated green tea still have the health-promoting
phytochemical called Epigallo-catechin-gallate (EGCG)??

A: ??not all methods to remove caffeine are equal?[one] method using
water and effervescence retains about 95% of the original content of
various catechins in green tea, including EGCG, compared to the method
using ethyl acetate which retains only ~30% of the ECGC?Be a label
reader, and call or write the company of a product that does not share
its decaffeinating method on the label to inquire about the method
used.?

(?Frequently Asked Questions,? Dr. Myers, MS RD:
http://www.cancerrd.com/FAQs/FAQ17.htm )

The same site mentions SALADA Green Tea?s site as offering further info:

?Q. How much caffeine is in Green Tea?
A. An average cup (6 oz) of green tea contains approximately 30
milligrams of caffeine?A brewed cup of Salada naturally decaffeinated
green tea contains only 2 milligrams of caffeine per cup.

Q. Does the decaffeination process affect the health benefits of Green Tea?
A. The effect of the decaffeination process on the health benefits of
green tea depends on the decaffeination process. Salada's
decaffeination process preserves the antioxidants found in green tea
by using only spring water and effervescence (CO2 method) to take the
caffeine out. Some other tea brands use the chemical, ethyl acetate,
which can destroy most of the best antioxidants found in green tea.?

(?Frequently Asked Questions,? SALADA: http://www.greentea.com/faq.html )

You may wonder why a decaffeinated tea would have any caffeine in it
at, but most do. ?It is important to note that even decaffeinated teas
contain small amounts of caffeine (typically 5mg to 10mg depending on
the type of tea and method of decaffeination). Only herbal and fruit
teas are completely free of caffeine (the notable exception being
yerba mate).? (New World Tea:
http://www.newworldtea.com/health_benefits.html )

Health Keepers offers more information about what kind of
decaffeination to look for. ?There are two different types of
decaffeination processes used in tea. One is accomplished using ethyl
acetate, an organic solvent, and the other is with carbon
dioxide?.Both of these options are successful at removing caffeine
from tea leaves, but only the carbon dioxide process preserves the
majority of  the medical integrity.? The article goes on to explain
each decaffeination process and why one is more beneficial  than the
other. (?Understanding Decaffeination,? Health Keepers, PDF file: 
http://www.healthkeepers.net/healthkeepersmagazine/TwoThree/Individual%20Articles/02HealthNews.pdf
  Or use the Google cached text file:  
://www.google.com/search?q=cache:7Zn1IAVKMlYJ:www.healthkeepers.net/healthkeepersmagazine/TwoThree/Individual%2520Articles/02HealthNews.pdf+%22green+tea%22+decaffeinated+ECGC&hl=en&ie=UTF-8
available for a limited time.)

I hope this fully answers your question.

Kind regards,
Kriswrite

KEYWORDS USED:
?green tea" decaffeinated ECGC