• Guest - w'd love to know what you think about the forum! Take the 2025 Survey »

Caffeine and blood sugars?

GroovyLlama

Newbie
Messages
2
Type of diabetes
Type 1
Treatment type
Pump
Hi everyone,

I was wondering if anyone else experiences a peak in blood sugars after having coffee? At first I just thought that it may have been the milk so I switched to black coffee, but still find my BM goes up by 3-4 mmol/Ls. I know that caffeine can impair insulin sensitivity in Type 2s, so could this be the same for T1? I've asked my consultant and nurse but they just look at me as if I'm talking jibberish. :banghead::banghead:

Anyway, thanks for any help,
Caitlin
 
Yes, for sure. The caffine makes your body release Cortisol which is the same thing that makes your blood sugar rise in the mornings.

I take a couple of units when I get into the office to account for my next coffee or two.
 
On the other hand, I have noticed no difference whether I have coffee or not.

#everyoneisdifferent
 
Yes, for sure. The caffine makes your body release Cortisol which is the same thing that makes your blood sugar rise in the mornings.

I take a couple of units when I get into the office to account for my next coffee or two.

Thank you! Good to know I'm not completely crazy, haha.
 
In the book Think Like a Pancreas the author says you should avoid caffeine when doing basal checks, so it may have an effect on some people's bg levels.

3-4 mmol is quite a spike for a black coffee, why not switch to decaff as it tastes no different (well I don't think it does).
 
@noblehead, I tend to disagree on the caffeine free flavour. There's a certain bitterness that you get with caffeinated coffee that is missing from the decaff stuff.
 
@noblehead, I tend to disagree on the caffeine free flavour. There's a certain bitterness that you get with caffeinated coffee that is missing from the decaff stuff.

I've not noticed Tim, obviously you don't get that caffeine-kick with decaff but taste wise I don't find any difference from my own experience, but much depends on the quality of the coffee (as it does with all coffee's and tea's), we buy Kenco Coffee which is a little more expensive than some brands you find in the supermarkets.
 
I have found this too. My sugars increase with caffeine. After my digging around i have found that the caffeine can interfere with insulin absorption. Because of this i cant have coffee anywhere near meals, because it messes with my bolus and lets the meal time carbs just raise my sugars.

If i have coffee away from meals i see a 1-2mmol/L raise as it blocks the basal from being absorbed.

None of this is science based, just what i have noticed combined with some stuff i have read in various places.

If you're drinking coffee with/just after a meal, then that could be why you see such an increase - it would slow the absorption of your bolus. So--umm stop doing that lol
 
have seen something similar though has been very inconsistent for me. So for day to day I stick with tea.
 
Patrick Holford recommends that coffee and meals should be taken apart. I assume because caffeine raises the blood sugar???
 
I drink loads and loads of coffee and diet coke. When I'm low carbing and occasionally have a 3g carb meal I don't need to bolus. I drink caffeine and my sugars don't rise at all. Maybe the caffiene affects us all in different ways
 
caffeine should have an effect on blood sugar because of cortisol release. This is something that also my consultant made me aware as I am literally espresso addicted. The effect I guess is different from person to person. I use a cgm and I can see a slight increase (1-2 mg ) after drinking espresso.
 
Back
Top