Skip to content


    Attention All WebMD Community Members:

    These message boards are closed to posting. Please head on over to our new WebMD Message Boards to check out and participate in the great conversations taking place:

    Your new WebMD Message Boards are now open!

    Making the move is as easy as 1-2-3.

    1. Head over to this page:

    2. Choose the tag from the drop-down menu that clicks most with you (and add it to any posts you create so others can easily find and sort through posts)

    3. Start posting

    Have questions? Email us anytime at

    Can coffee affect blood sugar?
    stlbob234 posted:
    I am a type II diabetic (recently diagnosed). My morning readings are ~150, but after drinking coffee (without food) they are above 200.

    flutetooter responded:
    How long after drinking the coffee do you test? Two hours later, or 1/2 hour or so? Coffee is listed as something to avoid for non-diabetics suffering from hypoglycemia -- low blood sugar. My thought is that it creates a surge of insulin which quickly burns up all the sugars and then leaves people low. Your pancreas may then click in quickly to create extra sugar. You may be measuring during one of these periods of rapid change.

    What do you put in your coffee in the way of cream or sugar? This may be causing the problem also.

    Also, without food in the morning, your pancreas will normally create sugar for your survival and it may create way too much. You must eat regular meals starting with breakfast and count your carbs at each one.
    xring responded:
    As a 1-cup-a-day (12-oz cup) coffee drinker, I was concerned about its effect on blood sugar. From what I've read & in my own experience, coffee has no effect on blood sugar - at least not a negative one.

    I'm talking about coffee, not one of those high-fat, high-sugar drinks from coffee houses.

    I put 1/2 - 1 tsp of sugar in my coffee & 1-2 tbsp of whipped cream (1 carb). That's only 2 - 4 carbs total. Remember that a medium-sized piece of fruit like an apple has 15 carbs, so I don't see how it would raise blood sugar. Besides, coffee is not gulped, it is sipped over a period of time.

    Since my stomach is never empty, I can't say what coffee would do on an empty stomach. I do know, however, that if I don't eat for 4-5 hours, my blood sugar goes up. A few days ago, after exercise, I tested at 88. I got busy doing something & didn't eat for 5 hours. I started feeling low, & tested at 159.
    DavidHueben responded:
    I am not sure there is a definitive answer to your question. I have read studies that support the position that caffeine raises blood glucose and others that say it has a glucose lowering effect. So, who really knows.

    I did give up drinking coffee a couple of years ago, because caffeine does raise blood pressure. Don't miss it one bit now.

    Louise_WebMD_Staff responded:
    Yes, it can.

    Here is an article: Caffeine Risks with Diabetes
    xring responded:
    I'm not sure that a caffeine pill (used in the study) would have the same effect on blood sugar as sipping coffee. Just as with vitamin pills vs food, the lack of other substances in the pill would change the absorbtion rate & maybe the metabolism of the caffeine.

    I don't drink my coffee with meals or food; I have a cup sometime between dinner & 10:00pm.

    Since caffeine is a stimulant, I'm wondering why it wouldn't stimulate the pancreas to produce more insulin.
    Michael_Dansinger_MD responded:
    Most of my patients who achieve diabetes remission continue to drink coffee. If they will eliminate cream and sugar from the coffee I don't complain about the caffeine. Still, you can see from the article that Louise posted, the caffeine can raise blood sugar. Switching to decaf or avoiding coffee would be a good move.

    You are recently diagnosed and I encourage you to do whatever it takes to try to achieve remission of the diabetes by sticking to an ambitious eating strategy and getting into a regular daily exercise routine.

    We're here to help!

    Michael Dansigner, MD
    ldowns09 replied to Michael_Dansinger_MD's response:
    I don't know if your going to get this as you posted this 4 years ago but I think i may be diabetic but my doctor hasn't diagnosed me yet. Last summer I was dying of thirst for months.. They did a panel of blood (fasting) and I was 1 number from diabetic.. Sense summer I go through spirts of dying of thirst.. And have recently over the last few months been so tired I'm literally fighting to stay awake. I feel like I've been up for two days straight and of course I haven't. Last night we had spaghetti around 6-630 and I had a bowl of ice-cream around 9:00 pm (bad I know) with melted peanut butter and chocolate sauce. This morning I had 3 cups of coffee with 6 Tbsp of sugar-free coffee-mate creamer (I like it sweet) and a slice of bacon. Two hours late I had a friend check my blood sugars and it was 82. Is that bad considering what I had lastnight and because I had coffee already in my system?
    brunosbud replied to ldowns09's response:
    " that bad...? The "reading" or what you're doing to yourself?
    An_251837 replied to ldowns09's response:
    No health expert replies to these posts anymore.

    You need to discuss all this with your doctor. Make an appointment and have him/her give you a script for fasting blood work - a test called an HbA1c. Your doctor will be the best one to tell you if that is 'bad'.
    NWSmom4g replied to An_251837's response:
    An_251837, the test for A1c does not require fasting.
    An_251837 replied to NWSmom4g's response:
    Fasting may not be required, but my doctor always has me do it as part of regular fasting blood work. He says the results are more accurate when done fasting. Plus it can be correlated to the fasting blood glucose test.

    The point I was trying to make is that idowns09 needs to see their doctor for answers.

    Helpful Tips

    Tip for Less Severe Neuropathy Symptoms
    I was diagnosed with Type 2 over eight years ago and have been lucky enough to control my disease with weight loss, diet and exercise ... More
    Was this Helpful?
    1 of 1 found this helpful

    Expert Blog

    Conquering Diabetes - Michael Dansinger, MD

    Dr. Michael Dansinger provides thoughtful tips for those with type 2 diabetes or pre-diabetes who want to reclaim their health...Read More

    Related Drug Reviews

    • Drug Name User Reviews

    Report Problems With Your Medications to the FDA

    FDAYou are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.