"Co-administration of green tea or EGCG may represent an effective means to reduce the glycemic effect of high starch foods."
Trials have demonstrated that green tea extract may support weight loss and blood sugar control,(1-3) but scientists have not been sure of the mechanisms involved.
Now food & obesity researchers at Penn State could have the answer. As reported in the November issue of Molecular Nutrition & Food Research:(4)
• They fed corn starch to a group of fasting mice and administered relatively small amounts of EGCG (epigallocatechin gallate, a polyphenolic compound found in green tea) to half the group.
Corn starch is a pure carbohydrate supply within the corn kernel that feeds the protein-rich germ as it sprouts to form a new plant. This starch is composed of chains of glucose (sugar) molecules, and a spoonful of corn starch is converted to a spoonful of blood sugar in the digestive tract within minutes after it’s consumed.
• The Penn researchers found that the peak post-prandial (after meal) blood sugar levels of the mice receiving ECGC averaged 50% lower than those of the corn-starch-only mice.
• This difference was not found in other groups of mice being fed EGCG along with different types of sugar (EGCG plus maltose, and EGCG plus glucose)...
• Suggesting that EGCG promotes inhibition of the digestive process that converts starch to blood sugar (inhibits action of the starch-digesting pancreatic enzyme alpha-amylase, called 'amylase-mediated starch digestion').
• To verify this suggestion, further tests in the lab found that EGCG inhibited pancreatic amylase activity - by one third (34%).
The implications for human weight & blood sugar management? "The relatively low effective dose of EGCG makes a compelling case for studies in human subjects," the researchers conclude.
1. “Research Links Green Tea to Weight Loss,” Feb 2012.
2. “Video: Fat Burning Via Flavonoids”
3. Laboratory studies on weight control & prevention of metabolic syndrome by green tea, Dec 2010
4. Cited article: “Inhibition of starch digestion by the green tea polyphenol, (-)-epigallocateghin-e-gallate” [EGCG], Molecular Nutrition & Food Research, Vol 56, #11, Nov 2012. By Forester SC, Gu Y, Lambert JD. Center of Excellence for plant and Mushroom Foods for Health, Dept of Food Science, Pennsylvania State University, University Park, PA, USA. [Email Dr. Joshua D Lambert, firstname.lastname@example.org]