Coffee, that beloved elixir of wakefulness, is an integral part of many people’s daily routines. For people with type 1 diabetes (T1D), the impact of coffee (or anything containing caffeine) is a bit more complex.  

Beyond its rich aroma and robust flavor, coffee can significantly affect blood sugar levels and insulin needs. This article will shed some light on how your favorite caffeinated beverage might impact your blood sugar. 

Coffee, Caffeine & Blood Sugar 

For people with T1D, keeping blood sugar levels in range is a constant juggling act. Coffee, it turns out, can influence this delicate balance. Here’s how: 

  •  The Message Caffeine Tells Your Liver: Caffeine, the primary stimulant in coffee and other delicious beverages, can temporarily raise blood sugar levels by triggering the release of stress hormones that prompt the liver to release stored glucose into the bloodstream. The result? A short-term spike in blood sugar levels. (Although, for some people, it could persist for hours!) Some people don’t experience this. Others need a significant dose of insulin, even for black coffee. Some people might see no impact from one cup but a spike in blood sugar for additional cups, or only if they caffeine later in the day! Everybody is a little different. But drinking coffee/caffeine all day long can potentially lead to a blood sugar roller coaster for some.
  • The Potential of Delayed Hypoglycemia: While coffee can lead to temporary spikes in blood sugar, it can also be a double-edged sword. For some with T1D, the caffeine-induced blood sugar rise might be followed by a rapid drop, leading to low blood sugar. Keeping a close watch on your blood sugar trends in the hours following your coffee can be especially important for a person living with T1D who’s already managing the challenges of insulin therapy. 
  • The Dawn Phenomenon Factor: Dawn phenomenon is a normal hormonal “event” in the early hours of the day, often between 4 a.m. to 8 a.m. The hormones your body produces to help you wake up for the day can tell your liver to release stored glucose, leading to a spike in your blood sugar. Adding coffee to the mix can complicate something already complicated — which simply means you might have two factors to consider when dosing insulin at this time of day. 
  • The Side-Effect: Insulin Sensitivity or Insulin Resistance: Some studies suggest that habitual coffee consumption may lead to increased insulin sensitivity — but others experience the complete opposite. For most, the way caffeine triggers your liver to release stored glucose is going to lead to a spike in blood sugar, which requires more insulin. Insulin can store that extra glucose as body fat, making it harder to lose weight. This means people with T1D might want to keep an eye on how much caffeine they are consuming throughout the day. Constant caffeine consumption throughout the day can also mean you need more basal/background insulin, contributing to potential weight gain. Moral of the story: how much caffeine you drink matters, even if it doesn’t include obvious calories.
  • The Diet Soda Dilemma: Diet soda is quite the debate! Some swear by its harmlessness, while other research raises concerns about its potential risks. Regardless of what research you believe about sweeteners like aspartame, people with T1D should remember that many diet sodas still contain caffeine, which can raise blood sugar. Just because it contains zero calories doesn’t mean drinking it all day long doesn’t come without potential side effects.
  • The Impact of Additives: How you take your coffee matters, too. Sweeteners and high-calorie creamers can raise your blood sugar level, especially if you’re not calculating insulin to cover those carbs. Low-sugar dairy alternatives like unsweetened almond milk can help minimize the impact on blood sugar. When it comes to alternative sweeteners, be thoughtful — many can still raise blood sugar despite the claims on the packaging.

Moderation & monitoring 

Like many things in life, moderation is key. Coffee can be a part of a healthy lifestyle for people with T1D, but it still requires some thought and awareness. Here are some tips to consider:   

  •  Know Your Limits: Pay attention to how your body responds to coffee and caffeine. If you notice significant blood sugar fluctuations, take good notes! It might be time to reassess your coffee or diet soda consumption.
  • Timing Matters: Be mindful of when you drink your coffee, diet soda, etc. Consider how it fits into your overall meal and insulin schedule and its impact in the morning vs. the afternoon. Those little details can matter big time in T1D.
  • Stay Hydrated: Caffeine is a diuretic, making you pee more. Dehydration can raise blood sugar levels because less water in your blood means the glucose becomes more concentrated. Dehydration thickens your blood, making it harder to flow through your body and provide your tissues with oxygen and nutrients. When dehydrated, your body also releases hormones that could raise blood sugar levels to conserve water. This also leads to more frequent urination, which can worsen dehydration. Long story short: drink plenty of water!
  • Read the labels: If you are using coffee additives, read labels carefully to understand their carbohydrate content and potential impact on your blood sugar.

Savor that cup of joe 

Coffee is more than a beverage; it’s a ritual, a comfort, and an essential part of countless mornings. If you live with T1D, understanding the relationship between coffee, caffeine, and blood sugar is crucial.  

As always, it’s essential to work closely with healthcare providers to navigate the intricacies of T1D management, coffee included. So, go ahead and savor that cup of joe, but do it with awareness and discretion. 

DISCLAIMER: The content in this article should not substitute for medical guidance from your healthcare team. Please consult your healthcare team before making any changes to your diabetes care regimen.