Fasting is recommended prior to taking blood tests that examine a variety of compounds, mainly cholesterol, triglycerides and blood sugars. You should drink only water for at least eight hours prior to fasting blood tests because of the potential for food and beverages to alter your blood’s composition and produce misleading results. Black coffee, even without sugar, affects your blood sugar levels because of its caffeine content. Consult with your doctor about the dietary restrictions prior to any blood test or medical procedure.
Fasting Blood Sugars
Your blood sugar levels are tested to check your body’s ability to produce or react to insulin, which is needed to shuttle glucose from your bloodstream into cells where it can be utilized for energy. High fasting blood sugar is an indication your pancreas is not producing enough insulin, termed Type 1 diabetes, or your tissues are resistant to the effects of insulin, which is called Type 2 diabetes. According to MedlinePlus, blood glucose levels up to 100 mg/dL are considered normal for a fasting blood glucose test, whereas levels between 100 and 125 mg/dL are possibly indicative of a “prediabetes” condition and levels above 126 mg/dL are usually thought to represent diabetes.
Black Coffee
Most people realize that coffee with sugar and milk can affect their blood glucose levels, but according to MayoClinic.com, black coffee also affects blood sugars because caffeine can impair insulin action, especially in people with Type 2 diabetes. However, Dr. Maria Collazo-Clavell notes that caffeine does not necessarily raise blood glucose levels in young, healthy adults, and at least 2 or 3 cups of brewed coffee are needed to have an effect. Decaffeinated black coffee may be all right to consume in small amounts while fasting, but you should ask your doctor to clarify the dietary restrictions for you.
Research
According to a Duke University Medical Center study published in the February 2008 edition of “Diabetes Care,” moderate caffeine consumption caused higher overall blood glucose levels in people with Type 2 diabetes. The researchers speculate that caffeine increases the hormone levels of epinephrine, which reduces glucose metabolism and leaves more of it in the bloodstream. Caffeine also affects receptors in your brain that inhibit glucose transfer into your cells. These properties of caffeine would also affect people without diabetes, but they are enhanced in people who already have issues with insulin sensitivity and glucose metabolism.
Other Effects on Blood
In addition to increased blood sugars, drinking black coffee has acidic effects on your body and blood because of its low pH. Your blood must be strictly maintained at an alkaline pH of near 7.4 in order to efficiently exchange oxygen, nutrients and wastes. Consuming acidic foods and beverages, especially ones with added refined sugar, forces your body to compensate by removing alkaline minerals from your bones and depositing them in acidic tissues and fluids. The acidic affect of coffee doesn’t alter blood glucose levels, but it does negatively impact your health in large doses.
Member Comments