TORONTO - As you gulp your cup of java and then chow down on some breakfast cereal, you may wish to consider new research looking at the possible effects when these two morning favourites are combined.

Drinking caffeinated coffee an hour before eating a bowl of cereal can significantly affect the body's blood-sugar response, according to the small study conducted at the University of Guelph in Ontario.

Terry Graham, chair of the department of human health and nutritional sciences, says this is of no consequence to healthy individuals. In fact, he notes that epidemiological studies have shown quite conclusively that prolonged decades of heavy coffee drinking decrease the risk for Type 2 diabetes.

But, he said, the study's findings might have implications for those who are diabetic or at risk of diabetes.

"If you were a Type 2 diabetic or thought you were at risk, why wouldn't you drink decaf? Because then you've got all the benefits of the coffee, and not the negative of caffeine," Graham said Tuesday in an interview from Guelph.

For his experiments, he and his colleagues recruited 10 healthy men. On different occasions they drank decaffeinated coffee or caffeinated coffee one hour before eating the cereal. Two cereals were involved in the study - Kellogg's All-Bran, considered to have a low glycemic index, and Kellogg's Crispix, which is considered a high glycemic index cereal.

"If you have caffeinated coffee what you find is that the insulin levels go higher than they would've if you didn't have the caffeinated coffee with that particular cereal," said Graham, who has been working with caffeine and insulin resistance in the lab for more than a decade.

"When you got up, you had your coffee and then you thought, 'Well, I had better behave myself and I'll have All-Bran,' and in fact the blood-sugar response to the All-Bran exceeded what the subjects showed if they had decaf and Crispix," he said.

"So by simply combining what you might think of as a more optimal cereal with coffee ended up giving you a response that was larger than what you would have expected from the less optimal cereal."

The research paper, published online last week by the American Journal of Clinical Nutrition, calls for more research in the area, and also notes a number of limitations to the study.

There were only a small number of participants and they were all healthy men.

Sharon Zeiler, senior manager, nutrition at the Canadian Diabetes Association, said she found the study interesting but wondered why the coffee was so strong.

"It seemed to be pretty strong coffee - five milligrams of caffeine per kilogram of body weight," she noted.

"So that would mean that someone who's, say, 90 kilograms, which is 200 pounds, which is not unusual in Canadian society, would've had 450 milligrams of caffeine ... Health Canada suggests 400-450 milligrams of caffeine in a whole day. So that's pretty strong coffee."

"So that, also, might have influenced the results."

She also noted that none of the study subjects was diabetic.

"I think that there would be a little bit of a difference in people who have diabetes who already have insulin resistance," she said.

"In order to gauge the effect on people with diabetes it would be necessary to actually run this experiment in people with diabetes."

As for drinking coffee at the same time as consuming cereal - rather than an hour earlier - Graham noted that other research finds only a modest impact on blood-sugar response.

But there was a "marked impact" when a carbohydrate-based lunch was eaten later, he said.

"The insulin levels went quite high ... You dodge the bullet at breakfast, but it got you between the eyes at lunch."

He added that caffeine levels just barely start to go down in a person three hours after drinking coffee.

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