We have been looking at all sorts of new medical devices and medications for diabetes here for months now, so it is refreshing to be able to talk about simply drinking tea as a possible preventative and treatment. I would certainly enjoy that.
The Effects of Green Tea on Obesity and Type 2 Diabetes
Various studies have shown the beneficial effects of green tea, not only on cardiovascular diseases but also on obesity and type 2 diabetes itself [6,7]. In a retrospective cohort study performed in Japan, a 33% risk reduction of developing type 2 diabetes was found in subjects consuming six or more cups of green tea daily compared to those consuming less than 1 cup per week [6]. Wu et al. [7] reported that Taiwanese subjects who had habitually consumed tea for more than 10 years showed lower body fat composition and smaller waist circumference. Evidences from epidemiological studies suggest the possibility of green tea being a novel strategy for treatment or prevention of obesity and diabetes.
However, a limited number of clinical trials using green tea, green tea extracts (GTEs), or its main ingredient catechin have shown disappointing results in controlling hyperglycemia in type 2 diabetic patients or protecting the condition in healthy subjects.
GC [gallated catechin] acutely reduces blood glucose levels mainly through its activities in the alimentary tract while increasing the glucose level when in the circulation by blocking normal glucose uptake into the tissues. They suggested the development of nonabsorbable derivatives of GC with only positive luminal effect as a prevention strategy of type 2 diabetes and obesity. As mentioned above, many researches are being performed to define the precise molecular mechanisms of green tea and ultimately, its clinical application in obesity and type 2 diabetes.
It is, of course, possible that these researchers are studying the wrong chemicals. A historical example is that when orange juice was shown to cure and prevent scurvy, a following study involved boiling the juice with the intention of concentrating the active ingredient. This destroyed the Vitamin C in the juice, leading to completely negative results, setting back research for decades.