Coffee affects the human body in a number of ways. Almost everyone is familiar with the jitters and anxiety that can occur when you drink too much coffee, and many people have experienced a headache or a tired feeling if they miss their morning dose of java. These are relatively minor problems and usually short-term. But coffee can also affect how the body responds to insulin, and that can be more serious.
About Blood Sugar
If your blood sugar is too low, you have hypoglycemia and may develop symptoms of light-headedness, sweating and headache, according to Diabetic Care Services. But hyperglycemia, or high blood sugar, can also cause problems. The body tries to keep the blood sugar within an optimum range by secreting insulin. When you eat a meal, blood sugar rises as the food is digested, and the pancreas secretes insulin to bring the blood sugar down again. Then as the blood sugar comes back down, the body stops secreting insulin; if it didn't, blood sugar could go too low. This constant seesaw process depends on both the secretion of insulin at the proper time, and in the right amount, and the body’s ability to respond to the insulin. To paraphrase the fairy tale, the body uses insulin to keep the blood sugar not too high, not too low, but just right. People with type 2 diabetes develop an inability either to secrete insulin or to respond to higher blood sugars; the latter situation is known as insulin resistance, and that’s where coffee comes into the picture.
Caffeine and Insulin Resistance
Coffee with caffeine is more than just a favorite beverage; caffeine is a drug. Caffeine has been shown to affect the body’s response to insulin, which is called insulin sensitivity. A study in the February 2002 issue of “Diabetes Care,” found that caffeine decreased insulin sensitivity in healthy male volunteers by 15 percent when compared to placebo. In another study, reported in May 2008 in the “American Journal of Clinical Nutrition,” Moisey and colleagues found that coffee with caffeine significantly impaired insulin sensitivity in healthy men, while decaffeinated coffee did not have the same effect.
Caffeine and Coffee
Moisey’s group also wanted to look specifically at whether caffeine and caffeinated coffee have the same effects when it comes to insulin resistance, citing other research that shows moderate coffee intake protects people against type 2 diabetes. The researchers found that while pure caffeine and caffeinated coffee caused an increase in blood sugar, the effect was less for the coffee. This suggests, they say, that the protective effect of coffee when it comes to type 2 diabetes must be due to other compounds in the coffee.
So, does coffee actually cause insulin resistance? The answer at this point seems to be maybe. Coffee with caffeine may have an effect on insulin; caffeine alone definitely decreases insulin sensitivity. Particularly in light of the research results, if you have questions about insulin resistance and coffee it would be wise to discuss them with a qualified health care professional.
- Diabetic Care Services: Hypoglycemia and Hyperglycemia
- PubMed.gov: Type 2 Diabetes
- Diabetes Care: Caffeine Can Decrease Insulin Sensitivity in Humans
- American Journal of Clinical Nutrition: Caffeinated Coffee Consumption Impairs Blood Glucose Homeostasis in Response to High and Low Glycemic Index Meals in Healthy Men