Coffee, Tea, and Diabetes Risk

Drinking more coffee — both regular and decaffeinated — and tea appears to lower the risk of developing Type 2 diabetes, according to new research published in the Archives of Internal Medicine. Should the protective effects of these beverages prove to be real, the implications could be substantial for the roughly 380 million people worldwide expected to have Type 2 diabetes by 2025.


Using a type of research known as meta-analysis (in which statistics from several studies are combined and examined), researchers looked at data from 18 studies, with a total of 457,922 participants, that analyzed the association between coffee consumption and diabetes risk. Six of these studies also looked at decaffeinated coffee, while seven studies analyzed the association between tea consumption and diabetes risk.

When the results of the studies were combined, it was found that each additional cup of coffee consumed in a day was associated with a 7% reduction in the excess risk of diabetes. Drinking three to four cups of caffeinated coffee per day was associated with a 25% lower risk of diabetes than drinking two cups or less per day; consuming three to four cups of decaffeinated coffee daily was associated with an approximately 33% lower risk. Similarly those who drank three to four cups of tea per day were found to have a roughly 20% lower risk of diabetes than those who did not drink any tea.

Because of the apparent reduction in diabetes risk associated with decaffeinated coffee, the protective effects of this beverage appear to extend beyond just caffeine content. The study authors theorized that other substances in coffee and tea, such as magnesium and antioxidants, might also be involved.

Nonetheless, Lars Rydén, spokesman for the European Society of Cardiology, notes that while drinking coffee may be protective, it is not the most important step for warding off diabetes: “Coffee helps, but other things are even more important. Those who are overweight should reduce their body weight by 5–10% — not too much — and include physical activity such as a brisk walk for 30 minutes a day. Then those people who are at risk of developing diabetes will reduce this risk by 40–50%.”

To learn more, read the article “Drinking Coffee, Decaf and Tea Regularly Associated With a Reduced Risk of Diabetes” or see the study’s abstract in the Archives of Internal Medicine.

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  • auddie

    I’m not sure about the coffee or the tea drinking, as I have had coffee all my life and am 78, have diabetis 2 and cancer and colitis and whatever. so if coffee does the trick god love us. I’d like to think my lomngevity is great, but the past month I have down wih divverticulitus, sugar has run amock and whatnot, guess it is the season. hope all goes well for all you coffee/tea lovers . have a happy holiday

  • Wayne

    My hypothesis on why coffee drinkers are less prone to develop type 2 diabetes is that they eat less. In general, people don’t feel like eating much after drinking a cup of coffee. Some people will have a cup of coffee instead of breakfast, or have a cup mid-morning and skip lunch. Though nutritionally void, it does provide a satiating feeling and the caffeine provides a shaky shot of energy.

  • kristina

    I have noticed that for me caffinated coffee raises my blood sugar. I currently drink the half caffinated 1/2 decafe and my sugars are better. I fix the caffinated that same way as the other so I don’t know what the differece is. I have been a tea and coffee drinker all my life and still developed type 2 diabetes. But at 33 I am taking charge and learning what I can have and what I can’t. and if giving up the caffinated for me is what it takes I am all for it. I just love my coffee.

  • derek

    This article is very general. Should diabetics drink coffee black (without sugar/cream)? Are all coffees and teas the same–are there any recommended types? Are there any cautions which must be considered?

  • Still too fat

    I think this may have something to do with the beverage’s anti-inflammatory properties. There may just be a correlation between inflammation and a number of chronic diseases and conditions.

  • Judy Peterson

    I would like to know if drinking coffee before
    having a blood ACI test done elevates your blood sugar?
    without sugar of course Judy

  • Alma Crabtree

    I am a type 2 diabetic over 30 years I am a coffee drinker and tea drinked Is ther any advantage for me I have been on insulin for about 20 of the 30 years

  • allan mohl

    I have diabetes 2 and havebeen a coffee drinker all of my adult life. Currently my blood sugar has gone way up and my appetite has decreased. Thus i wonder if your statistics are accurate. On the other hand, I am 76 years old and still very ac tive.

  • Carl D Taulbee

    Dear 78 year person.
    Good luck. I am 81 and have been a diabetic for 40years . I have always drank gallons of coffee, tea and beer, I’m inclined to think the beer helped with my longivity. The kidneys finally failed and I have been on Dialysis for about three years. Enjoy what is left!

  • Patrick

    I am sitting here with my vat of coffee (okay, it’s a really big mug) and a cinnamon roll (i’m a very very bad boy). I doubt they will balance each other out, but I am a coffeeholic and this article brought me a bit of joy this morning. Incidentally, I started back at the gym this past autumn, dropped 10-12 pounds and brought my bmi down from 38.6 to 37. I’m going to try to drop another 10-12 after the holidays finish, and the gym is a lifestyle change, not a passing thing. My a1c was 5.9 at the last doctor’s visit (I am taking actoplus). Visited the optometrist yesterday (using up benefits before I lose them) and the photograph of the back of my eye showed no bleeding, though at the ripe old age of 48 I have just been prescribed my first pair of bifocals. So… not being perfect, but trying to do more good than bad. Glad coffee is in the “good” column, even if it might show up there in small type.

    Time to refill the vat of coffee. One day they just may open up a Mrs. Olson wing of the Betty Ford clinic just for me.

  • shinaye

    Does this apply tp Type 1 diabetics 2?

  • Dr. G V Rao

    As a B’ Day and New Year wow I discontined consumption of coffee totally from 28th of December. Then after seeing your article encouraging to drink coffee for better health myself again started taking coffee ( with sugar free sweetner) not only once (That was my practice in the early morning) but twice in early morning and again in the afternoon. Soon a news item appeared in Yahoo on Jan 3rd on the latest research conducted indicates that coffee consumption is bad for people suffering from Diabetics Type 2. Now I am at a fix to take or not to take. I am the strict follower of what appears in Web Med and Merck Source and so I am at a fix to take or not to take coffee in the morning Kindlt advice

  • Bobbie, RN, Diabetes Ed

    I believe that this article is addressing more of the Pre-diabetes crowd and it also recommends the same lifestlye changes that are tried and true in regard to preventing of delaying type 2 diabetes. Which are of course, correct food choices and exercise.
    Also, just as soon as one study comes out another will come out contradicting points in the research. Again this is in reference to Pre-diabetes not diabetes. The article that was quoted as contradicting this article was involving a person with diabetes already.
    So, enjoy your coffee or tea in moderation if you have diabetes, if you test your blood glucose before and after to monitor the effects on you specifically, you can then decide for yourself what you should choose to do.
    Good luck and Happy New Year.

  • Jesus T Alonzo

    I beleive that just excerise will help diabetic type 2; and will keep your sugar level down.
    I don’t mean a full blown work out I just ride bike for 20 min and I do three sets. Now I do plan to increase my work out because 35lbs overweight!

    Now you must no everytime I do just one set of 20min on the bike I drop my sugar by 12-15 points or units!

    Wishing you a good year!

  • grandma308

    I’ve been drinking coffee for more than 50 years and still I developed type 2 diabetes about 10 years ago. Now I’m insulin-dependent, but still drinking coffee.

  • Randy

    it is amazing what can be found in studies. All those coffee drinkers out there must love this. Thanks Diane for the article.

  • Juliazamp

    Reading all the comments expressing risky, not risky quite scary…. Hope I remain prediabetic inspite of my decision to drink coffee at lreast once a day to wake me up and erase lethargic feelng. I feel I can!t give up coffee….ever! I leave it up to the Good Lord.

  • Ramesh


    Can i take medicine after taking Tea.Kindly Reply.