Caffeine does not appear to affect blood sugar when consumed in moderate amounts. This is good news since many Canadians start their day with a cup of coffee. This does not mean that people with diabetes can consume excessive amounts of caffeine. Drinking caffeine in large amounts as coffee over a short period of time has been shown to raise blood sugar. Caffeine does this by enhancing the effect of two hormones (adrenaline and glucagon). These two hormones release stored sugar from the liver resulting in high blood sugar.

Caffeine is one of the most widely used drugs. Caffeine affects the nervous system, can make you feel more alert, keeps you awake at night and causes a temporary rise in your blood pressure. A lot of research is being done on the effects of caffeine on heart disease, cancer, fibrocystic breast disease, bone loss and metabolism (the rate at which the human body burns calories). More research is needed before conclusions can be made.

Caffeine is known to pass from a mother to a developing baby and caffeine can also be found in the breast milk of mothers who drink excessive amounts of caffeine. Caffeine can lower the amount of iron taken in by the human body. Caffeine is a diuretic, which means it increases urine output beyond fluid intake. Keeping well hydrated is important for good health.

What is also important to think about is that the side effects of consuming excessive caffeine can feel like hyperglycemia (high blood sugar) or hypoglycemia (low blood sugar). The side effects of excessive caffeine consumption include headaches, poor concentration, irritability and nervousness. Many people feel these symptoms when their blood sugar is high or low.

Limiting the amount of caffeine a person with diabetes consumes can make it easier to read your body's symptoms of high and low blood sugar. Remember, using a blood glucose monitoring machine is the best way to know what your blood sugar is.