As you all know from reading the posts here at T Ching, there are a myriad of purported health benefits reported, and widely touted, from consuming tea. We all love to hear that and we have all been great proponents and disseminators of that information. As humans, it is only natural that we have our biases that we tend to view, and adhere to somewhat narrowly, and we lovers of Camellia sinensis are certainly no different. As a result, we often have blinders on when it comes to any negative or contradictory evidence we read or hear about. But, as we have also seen and heard, there is always some controversy concerning all the good news about tea. Given the abundance of supportive information about the healthy benefits of consuming tea, however, it is often easy to be dismissive of research that doesn’t support our bias.
Here at T Ching, we try very hard to present accurate information from both sides of a controversy, despite our biases as to what we would like to hear and report to others. We were one of the first to clarify the old myth about the easy decaffeination method of eliminating 80% of the caffeine on the first steep (and continue to publish posts on this issue), as well as publish information about the variability of caffeine content in all types of tea.
Another important controversy that has reared its ugly head from time to time is that, despite all of the health benefits reported as a result of the EGCG in tea, there has been contradictory research stating that the absorption of EGCG in the human digestive system is minimal and not enough to account for so many great health benefits. This issue has not been discussed very often and appears to be one of those issues that has been easily dismissed by the tea industry at large. At least for me, however, it has been a low-level, but chronically nagging, dilemma. It creeps back into my consciousness from time to time, causing me ever-so-slight discomfort whenever we get on our soapbox about tea.
Well, I am happy to report that I am now able to sleep a bit easier at night. There is a new study out of Italy with its stated goal being “to investigate green tea flavan-3-ol catabolism and plasma pharmacokinetic and urinary excretion by high-performance liquid chromatography with tandem mass spectrometry to evaluate their absolute bioavailability by taking into account all known and some unknown catabolites deriving from their interaction with the gastrointestinal tract and its host microflora.”
The results of this study, which involved 20 healthy human subjects, are very interesting in that they showed that EGCG, although highest in absolute concentration, was the only unmetabolized compound found in samples after 4 hours and 24 hours. What the researchers did find, however, was 39 other active catabolites of flavanols that showed up in concentrations of 39%. This study makes two important points. One is that we now have a more accurate explanation as to why tea appears to have so many health benefits. The other point is – as I have been commenting for years (just to toot my own horn a little) – it’s never good to put all of our allegedly identified isolated healthy constituent eggs in one basket. Although scientific research is based on deductive reasoning, that method of rooting out accurate information isn’t always the best. It is a very reductive way at looking at things and sometimes we need to consider the functioning of the whole. We now have a viable explanation that there are numerous other metabolites that may be exerting a great deal more influence on our health than the primary ones previously focused on. This reminds me of what happened eons ago, when Valium was the most widely prescribed benzodiazapine. It was described as a short-acting benzo that was supposed to last approximately four hours. The truth turned out to be something entirely different in that people were noticing much longer effects. It wasn’t until years later that they discovered that Valium had an active metabolite that remained in the body approximately 72 hours. In the inimitable wisdom of the pharmaceutical company, they quickly developed a new benzodiazapine – Oxazapam – based on that metabolite. I suspect we will start seeing concentrated extracts of some of these tea catabolites in the not-too-distant future.
One last bit of interesting information that also provides some insight into the contradictory nature of reported health benefits and reported low absorption levels of tea constituents – the research team from Italy also found that the microflora in the gut were involved in numerous catabolic reactions of other beneficial compounds found in tea and leading to compounds with much greater absorption levels. This, however, was variable depending on each individual’s own microflora makeup. This is further support of the importance of maintaining a healthy and strong digestive system. Doing so will insure greater health benefits from drinking tea, as well as greater health benefits from eating a healthy diet.