The findings suggests that chlorogenic acids found in unroasted coffee beans - and widely available as a dietary supplement - may help to battle the ever increasing global health problem of diabetes by aiding in the control of blood sugar levels and weight balance.
"A simple natural pill or capsule that would both help control blood sugar and foster weight loss at the same time would be a major advance in the treatment of type 2 diabetes," said Dr Joe Vinson from the University of Scranton in Pennsylvania - who led the research.
Speaking at the recent National Meeting & Exposition of the American Chemical Society (ACS), Vinson noted that his own research, in addition to that published by other scientists "suggest that such a treatment may, indeed, exist."
"There is significant epidemiological and other evidence that coffee consumption reduces the risk of type 2 diabetes," he stated. "One large study indicated a 50% risk reduction for people who drank seven cups of coffee a day compared to those who drank only two cups a day."
"The evidence points to chlorogenic acids as the active ingredients in coffee that both prevent diabetes and improve glucose control in normal, pre-diabetic and diabetic people," said Vinson.
"I am trying to make the coffee and diabetes story as clear as possible for the public."
Chlorogenic acids are a family of substances that occur naturally in apples, cherries, plums, dried plums and other fruits and vegetables.
Vinson pointed out that coffee ― due to its popularity as a beverage ― is the major dietary source of such substances. He noted, however, that higher levels of chlorogenic acids exist in green, or unroasted, coffee beans. Therefore, there has been a major focus on using concentrated extracts of green coffee beans, which contain high amounts of chlorogenic acids.
In a previous study, Vinson found that overweight or obese people who took such an extract lost about 10% of their body weight in 22 weeks.
The new study sought to document the effects of various doses of a commercial green coffee extract on the blood sugar levels of 56 men and women with normal blood sugar levels. All participants were given a glucose tolerance test to measure how their bodies responded to the sugar before consuming either 100, 200, 300 or 400 milligrams (mg) of the extract in a capsule with water for a period of time.
Follow-up glucose tolerance tests revealed that the extract affected responses.
"There was a significant dose-response effect of the green coffee extract and no apparent gastrointestinal side effects," Vinson said.
"All doses of green coffee extract produced a significant reduction in blood sugar relative to the original blank glucose challenge," he explained. "The maximum blood glucose occurred at 30 minutes and was 24 percent lower than the original with the 400 mg of green coffee extract and the blood glucose at 120 minutes was 31 percent lower."
Vinson noted that he has received funding from Applied Food Sciences, Inc. - a company that market a green coffee antioxidant product.