Chlorogenic acid (5-O-caffeoyl-quinic acid), an ester of caffeicacid with quinic acid, has received considerable attention
for its potential biological effects and wide distribution in nature (Clifford,1999). It is one of the most abundant polyphenols in the human
diet with coffee, fruits and vegetables as its major sources.Flowers and buds of Lonicera japonica Thunb,
and the leaves of Eucommia ulmodies, which are rich in chlorogenic
acids, are used in Chinese medicine. In the conventional method, chlorogenic acid is extracted from dried green coffee
powder by refluxing with solvent, followed by filtration. However, this technique is time- as well as energy-consuming and laborious. Development of a new technique for the separation and purification of chlorogenic acid is thus of essential importance for the potential application and use of chlorogenic acid.
Vinson and his colleagues gave the men and women in the study a 700-milligram (mg) dose of the ground coffee beans and a 1,050 mg dose. They also gave them a placebo
or inactive dose during the 22-week study.
The men and women cycled through each phase for six weeks. In between, they had ''wash-out'' periods where they didn't take any supplement. In this way, they served as their own comparison group.
"Their calories were monitored," Vinson says. They were not put on diets. Calorie intakes stayed about the same during the study. They averaged about 2,400 calories a day -- by no means a weight reduction plan.
They burned, on average, about 400 calories a day in physical activity, Vinson says. The study was done in India.
The 17-pound loss was the average. Some lost only about 7 pounds; others about 26 pounds.
Overall, body weight declined by an average of 10.5%. Body fat declined by 16%.
The study participants lost slightly more weight with the higher dose compared to the lower dose, but not a
significant amount with the placebo, Vinson says. Vinson can't say for sure why the coffee bean extract seems to
help weight loss. He suspects one explanation is the unroasted beans' chlorogenic acid.
Chlorogenic acid is a plant compound. It may have ''some effect on keeping down glucose absorption," which in
turn helps reduce weight, Vinson says.
Once coffee beans are roasted, the chlorogenic acid breaks down.
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