Eating low-sugar cereal may seem like the healthy choice, but drink a cup of coffee before breakfast and you might as well go for the chocolate corn pops.
Canadian researchers say drinking coffee before eating your morning cereal can affect the body's blood sugar response and cause blood glucose levels to rise dramatically especially when eating low-sugar cereals.
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Earlier research has shown that, ``Whether you're a healthy individual, obese or a type 2 diabetic, when you ingest caffeine and then follow that with some food that's carbohydrate-based for a prolonged period of time certainly six hours at least your body becomes insulin resistant,'' says Terry Graham, professor of human health and nutritional sciences at the University of Guelph.
For his study, Graham's team had 10 healthy men drink caffeinated coffee, decaf or a placebo (water) one hour before eating breakfast.
The coffee drinkers each drank roughly two cups of coffee. Then, on different days, the men ate either cereal with low levels of sugar (in this case, All-Bran) or a moderately sugary cereal (Crispix). Blood samples were taken over several hours to check for caffeine levels, blood sugar (blood glucose) and insulin responses.
``What we found was that both the resistance to insulin and the levels of glucose and insulin went up dramatically with either cereal if they had caffeinated coffee before the meal,'' Graham says.
What's more, the men who had coffee before eating the low-sugar cereal had higher blood sugar levels than those who drank decaf before eating the sweeter cereal.
``In other words, if you thought you were being a very good person and looking after your health and avoiding the sweeter cereal and taking the low one, and then saying, `Of course, I'll have my cup of coffee with it, in fact, your body was seeing something that was greater than if you had the sweeter cereal without coffee.''
``It's the caffeine in the coffee that is altering your body's sugar response,'' Graham says. ``It makes us resistant to insulin which in turn makes our blood-sugar levels go higher.''
The study appears in the most recent issue of the American Journal of Clinical Nutrition.
For healthy people, the implication is no big deal,'' Graham says. ``If my glucose goes a bit higher and I'm over it in a couple of hours, I'm happy, and I've had my coffee.''
The same doesn't hold for obese people who are sedentary and don't exercise. These people are already insulin resistant and at risk for type 2 diabetes.
``For those people who suspect they're at risk or are at risk or have diabetes, the caffeinated coffee with any cereal, anything that has carbohydrate in it, you are going to be experiencing a much bigger surge in blood glucose and your body will try, and hopefully can, produce enough extra insulin to manage it,'' Graham says.
He's not knocking coffee. Recent research shows very clearly'' that heavy coffee drinking decreases the risk for type 2 diabetes. Coffee contains many positive biological compounds, including antioxidants, and decreases the risk for diseases of the gut.
In the long term, consuming coffee for decades decreases your risk,'' Graham says. ``The obvious thing to me is: Drink decaf. You'd have all the good, and you wouldn't have the transient hit of caffeine.''
Although this study included men only, Graham said he has unpublished data showing women as well as older, middle-aged and overweight people and diabetics responding in a similar way.