If your morning commute usually includes a greasy breakfast sandwich and a stiff cup of joe, here's another reason to trade it all in for a fruit cup.
A new study from the University of Guelph found that chugging a coffee after a fatty meal of fast food can spike blood sugar in a healthy person to a level similar to those at risk of diabetes. Eating a greasy meal, we already knew, caused spikes in blood sugar. But the dangerous cocktail of caffeine and grease doubles the impact.
Researchers at the University of Guelph say that eating saturated fat makes it harder for the body to clear sugar from the blood - drinking coffee, even a couple of hours later, only makes that job harder.
"This shows that the effect of a high-fat meal can last for hours," said Marie-Soleil Beaudoin, a PhD student who conducted the study with University of Guelph professors Lindsay Robinson and Terry Graham.
In the study, published in the Journal of Nutrition, participants were given a special fat beverage, and then asked to eat a meal with a sugar drink six hours later. Typically, the body should produce insulin to remove sugar from the blood. (People with diabetes do not produce enough insulin.)
But with the high-fat beverage in their system, the blood sugar levels in participants were 32 per cent higher than those who had not consumed any fat.
And in the second part of the experiment, when participants were also asked to drink two cups of coffee five hours after the fatty drink and then down a sugar beverage, blood sugar levels were 65 per cent higher than the control group.
"Having sugar remain in our blood for long periods is unhealthy because it can take a toll on our organs," said Ms. Beaudoin, in a release from the university.
The study, she said, stresses the need for people at risk of diabetes or with the disease to avoid both high-fat foods and limit their caffeine.