If you have diabetes, you may have noticed something surprising: your blood sugar sometimes rises after drinking coffee, even when your coffee contains little or no sugar. So, does caffeine raise blood sugar?

Short answer? It can, especially in people with diabetes, but the effect varies from person to person.

According to the Mayo Clinic, caffeine may affect how your body uses insulin. For some people with diabetes, consuming around 200 milligrams of caffeine can lead to higher or lower blood sugar levels. For others, caffeine has little noticeable effect.

Why Can Caffeine Affect Blood Sugar?

Caffeine can temporarily affect insulin sensitivity and stimulate the release of hormones such as adrenaline. These changes can encourage the liver to release stored glucose into the bloodstream.

The American Diabetes Association also notes that caffeine can raise blood glucose in some circumstances, partly because it can trigger the release of stored sugar from the liver.

This doesn't necessarily mean coffee is unhealthy for people with diabetes. In fact, the relationship between coffee and diabetes is considerably more complicated. Research has found that both caffeinated and decaffeinated coffee consumption are associated with a lower long-term risk of developing type 2 diabetes.

What About Flavored Coffee?

The coffee itself may not be the biggest issue. What you add to it can matter significantly.

Plain coffee contains essentially no carbohydrates or added sugar. However, sweetened creamers, syrups, flavored sauces and other additions can substantially increase the carbohydrate and sugar content of a coffee drink. The American Diabetes Association recommends limiting beverages containing added sugar, including sweetened coffee.

This is also why it's useful to distinguish flavored coffee from a sweetened coffee beverage. Coffee beans or pods can have flavors such as vanilla, chocolate or caramel without necessarily containing the same amount of sugar found in a coffee-shop drink loaded with syrups and cream.

Should You Stop Drinking Coffee?

Not necessarily. If you have diabetes, pay attention to how your own blood sugar responds to caffeine. Some people may notice a rise after caffeinated coffee, while others may see little or no change. Also, if you're a fan of flavored coffee, all the coffee at Roasty Buds is zero sugar (and gluten-free, non-dairy).

Mayo Clinic notes that up to 400 milligrams of caffeine per day is generally considered safe for most healthy adults, although individual circumstances can differ.

If you're concerned about repeated blood sugar changes after coffee, consider discussing your caffeine intake with your healthcare professional.