View Full Version : Green Tea extract decreases starch digestion and absorption from a test meal in human

12-25-2015, 04:53 PM
The study comprised of 28 healthy, adult volunteers (19 women and 9 men, aged 19–26 years old) recruited from Vocational Technical High School for Computer Science in Nakło nad Notecią, Poland. All subjects were recruited after they presented at an appointed meeting and showed willingness to participate the study, which was thereafter confirmed by informed written consent. The health status was defined as such: no physical complaints in the month preceding the study, no acute or chronic disease, no current pharmacotherapy, no past hospitalizations for gastroenterological indications, and good nutritional status defined as weight, height, and BMI within normal reference values. As the subjects were to ingest milk, a hydrogen-methane breath test was performed in each subject, to exclude lactose malabsorption. In the first week of study, some of the participants ingested the test meal with GTE while the others ingested placebo. The order of the first test (GTE/placebo test) was determined according to the randomization list. The second test followed in a crossover manner. One week later, subjects who took GTE in the previous test were given placebo, and those receiving placebo in the previous week were given GTE. In this way subjects were internal self-controls to themselves.

All subjects fasted for 12-hours. After collection of baseline breath samples for 13CO2 analysis, the subjects ingested a test meal consisting naturally 13C-abundant cornflakes (50 g cornflakes + 100 ml low- fat milk). The total energy load of the test meal amounted to 234 kcal, and it consisted of 7.0 g protein, 46.5 g carbohydrates, and 2.2 g fat. Concurrently with the test meal, a group of the subjects ingested GTE (GTE 4 g, EGCG content –257.6 mg) in a powder form enclosed in digestible starch wafer, whereas the others ingested an empty starch wafer (placebo control). The subjects were assigned to the groups randomly. Breath samples were collected at 30, 60, 90, 120, 150, 180, 210, and 240 minutes after the test meal ingestion. One week later, the procedure was repeated, though the subjects ingested the opposite preparation from that ingested in the initial study.

The obtained data show that a single dose of GTE ingested with the test meal may limit the digestion and absorption of dietary starch in humans. The dose of GTE (4 g, EGCG content −257.6 mg), established according to pharmacokinetic studies, is equivalent to at least several cups of green tea16,17. As the usual daily intake of green tea is smaller than the dose used in our study, its effect may be not as pronounced. Some commercially available green teas may differ in total amount of polyphenols, even to as little as 15% polyphenols. To the best of our knowledge, this is the first study evaluating the effect of pure GTE on the digestion and absorption of starch with the use of a plausible method.

Full Text:http://www.nature.com/articles/srep12015

12-25-2015, 05:00 PM
Need to see this study replicated with corn pops instead of corn flakes for a better assessment.