November 9, 2012
Drinking Green Tea Could Help Lower Blood Sugar Spikes
Lee Rannals for redOrbit.com — Your Universe Online
According to Penn State food scientists, green tea and starchy food could help to lower blood sugar spikes.
Mice were fed epigallocatechin-3-gallate (EGCG), an antioxidant found in green tea, and cornstarch during the study.
Joshua Lambert, assistant professor of food science in agricultural sciences, said this mixture led to a significant reduction in an increase in their blood sugar levels compared to mice that were not on the diet.
"The spike in blood glucose level is about 50 percent lower than the increase in the blood glucose level of mice that were not fed EGCG," Lambert said in a statement.
The researchers separated mice into several groups during the study, according to body weight. After a fasting period, the mice were given common cornstarch, maltose, or sucrose. One group of mice received EGCG along with the feed, while a control group was not fed the compound. The team tested the blood sugar levels of both groups.
The team said EGCG was most effective when the compound was fed to the mice simultaneously with cornstarch. This research may mean that green tea could help humans control the typical blood sugar increases that are brought on when they eat starchy foods, such as breads and bagels.
"If what you are eating with your tea has starch in it then you might see that beneficial effect," Lambert said in the statement. "So, for example, if you have green tea with your bagel for breakfast, it may reduce the spike in blood glucose levels that you would normally get from that food."
The EGCG had no significant effect on blood sugar spikes in mice that were fed glucose or maltose. Lambert said the reason blood sugar spikes were reduced with mice that ate starch is because it may relate to the way the body converts starch into sugar.
Alpha-amylase is an enzyme that is produced in both the mouth and by the pancreas, helping to break down starch into maltose and glucose. EGCG could inhibit the enzymes ability to break down the starch, the team believes.
If the mechanism holds true in humans, this may mean that people who want to limit the blood sugar spike could skip adding sugar to their cup of green tea.
"That may mean that if you add sugar into your green tea, that might negate the effect that the green tea will have on limiting the rise in blood glucose level," Lambert said in a statement.
He added that the green tea and the starch would need to be consumed simultaneously. Drinking a cup of tea a little while after eating a piece of toast would probably not be effective.
The researchers will begin to test the compound on people next.
"The relatively low effective dose of EGCG makes a compelling case for studies in human subjects," the researchers said.
They reported their findings in the online journal Molecular Nutrition and Food Research.