Increasing daily coffee consumption may reduce type 2 diabetes risk

People who increased the amount of coffee they drank each day by more than one cup over a four-year period had a 11% lower risk for type 2 diabetes than those who made no changes to their coffee consumption, according to a new study led by Harvard School of Public Health (HSPH) researchers. In addition, the study found that those who decreased their coffee consumption by more than a cup per day increased their type 2 diabetes risk by 17%.

“Our findings confirm those of previous studies that showed that higher coffee consumption was associated with lower type 2 diabetes risk,” said Shilpa Bhupathiraju, lead author and research fellow in the Department of Nutrition at HSPH. “Most importantly, they provide new evidence that changes in coffee consumption habit can affect type 2 diabetes risk in a relatively short period of time.”

The study appears online Thursday, April 24, 2014 in Diabetologia (the journal of the European Association for the Study of Diabetes).

The researchers analyzed data on caffeinated and decaffeinated coffee, and caffeinated tea consumption from 48,464 women in the Brigham and Women’s Hospital-based Nurses’ Health Study (1986-2006), 47,510 women in Nurses’ Health Study II (1991-2007), and 27,759 men in the Health Professionals Follow-up Study (1986-2006). Participants’ diets were evaluated every four years with a questionnaire, and those who self-reported type 2 diabetes filled out additional questionnaires. A total of 7,269 cases of type 2 diabetes were documented.

Results showed that participants who increased their coffee consumption by more than one cup per day (median change=1.69 cups/day) over a four-year period had a 11% lower risk of type 2 diabetes in the subsequent four years compared to those who made no changes in consumption. (A cup of coffee was defined as eight ounces, black, or with a small amount of milk and/or sugar.) Those who lowered their daily coffee consumption by more than one cup (median change=2 cups/day) had a 17% higher risk for diabetes. Changes in decaffeinated coffee consumption and caffeinated tea consumption were not associated with changes in risk for type 2 diabetes.

“These findings further demonstrate that, for most people, coffee may have health benefits,” said Frank Hu, senior author and professor of nutrition and epidemiology at HSPH. “But coffee is only one of many factors that influence diabetes risk. More importantly, individuals should watch their weight and be physically active.”


Substack subscription form sign up

54 thoughts on “Increasing daily coffee consumption may reduce type 2 diabetes risk”

  1. As an avid coffee lover,coffee is morning elixir to me it gives me an early jump-start for the day.I am always told how unhealthy coffee is because whenever there is a chance I will make myself a warm cup of coffee,I guess that is just a mere myth.

    Studies shows that 3 cups a coffee a day is the maximum one person can take in.Coffee is quite the treat for a lot of people,I wonder if too much of sugar and milk contribute to the amount of coffee I should take per day.I am very grateful to know that decaffeinated coffee and caffeinated tea had no effect on the diabetes risk.I am very interested in what happens on a molecular level in coffee that leads to this decreased risk for type 2 diabetes.

    In my studies I have learnt that coffee consumption is associated with a decreased risk of type 2 diabetes.Suggested mechanisms underlying the association have included attenuation of subclinical inflammation and a reduction in oxidative stress.Coffee consumption led to an increase in coffee-derived compounds,mainly serum caffeine,chlorogenic acid,and caffeic acid metabolites.Coffee consumption appears to have beneficial effects on subclinical inflammation and HDL cholesterol,whereas no changes in glucose metabolism were found in my study.Futhermore,many coffee-derived metabolism methylxanthines and caffeic acid metabolites appear to be useful as biomarkers of coffee intake.

    Although there was a lower risk of diabetes among decaffeinated coffee drinkers,increasing or decreasing consumption made no difference.Whats interesting is that when you are a diabetic,you are told to avoid coffee because it raises your blood sugars-the very definition of what diabetes is.

  2. I truly want to believe this article because I normally drink more than 4 cups of coffee every day but this article is not reliable for me sadly. They didn’t mention about other external factors. Diabete is also affected by exercising amount, sugar consumption, life-style, etc.
    If this article was the experiment which all the sample people have the same condition of living and the food, and also exercise. Then it would be reliable.
    Also, what I wanted to know when I was reading article is that how many cups of coffee is the best for the day but it didn’t mention the maximum cups of coffee which can make the body healthier. There would be a someone who would think lots of coffee is good so drink more than 6~7 cups a day but I’m sure that too much is even worse than nothing. If this article mentioned about the best caffein intake amount, then I would drink as possible as that amount even if it’s false.
    In addition, I want to know how the coffee consumption may reduce diabetes risk. If this is mentioned then this article would be fully reliable but this article didn’t mention about how. Also, this article talks about ‘how to make a good coffee for diabetes’ but it’s not really well emphasized for me so I want to recommend the writer about changing font, or giving a different colour to give emphasize about the amount of sugar and milk, because too much sugar will destroy diabete sufferers’ body function.

  3. Not to sound cynical but when a desired outcome is really wanted it is easy to “manipulate” certain conditions to fall into the favour of the desired outcome. Based only on this article there are a few points that I believe adumbrate why this article can not be taken directly as true. Firstly the definition of coffee as given by the article, “A cup of coffee was defined as eight ounces, black, or with a small amount of milk and/or sugar
    Read more at https://scienceblog.com/71967/increasing-daily-coffee-consumption-may-reduce-type-a2-diabetes-risk/#hquSFCmlQoS7a3xU.99” There are a few problems that arise with this statement alone, firstly two different people will not have the same perspective as to what a “small amount” is. When stating a definition of one of the main variables the definition can not be this vague, the findings will be based on the definition and when the definition is flimsy or open to interpretation then it can not be used, science strives on being accurate with everything. By not having a full very specific definition there is always going t be room for error and misinterpretations to enter the equation. The second main problem with this definition is that it only states eight ounces. Talk to any coffee fanatic and they will tell you that two different types of coffee are not the same, lets take a simple example, Frisco and Nescafé Gold. Frisco has more Chicory than actual coffee, so what does this say? According to the definition, “coffee” that is made out of something that is not pure coffee beans is coffee. Now where does leave us? Evidence that was gathered has been based on too free a definition. Thus showing that the definition is flawed already.

    Another problem is the all the external factors that will play a role in the equation. There is no mention of lifestyle choices and how they may increase or decrease the chances of getting type 2 diabetes. Obese people have a higher chance of getting diabetes, whilst people who try follow healthy diets have a much lower chance of getting diabetes. There are many things that can cause diabetes in people, and some of these reasons lets say hereditary diabetes, where diabetes runs in the blood line and it’s possible for a person who belongs to this blood line can also stand in line to have diabetes, and no amount of coffee can refute the genes that have been in our bodies our entire lives, so there are parts that were not fully explored, furthermore there is an outrageous lack of what the experiment took as “test dummies. The test could have been run on people who would have had a very little chance of getting diabetes, or people who are so close to having type two diabetic. The could have been told to change their diet by the physicians to by who ever, so even something as simple as that can have disastrous affects on the final outcome.

    I truly am a lover of all things coffee, some might even say I’m a coffee snob, so I would love for this notion to be true as much as the next person as this would justify having more coffee every day, but as I said in they article there is not enough information for us to even begin to accept what has been stated as true. For a future experiment to be successful, more things have to be unified, a specific type of coffee must be defined as the only coffee for the test and secondly different lifestyle choices must be incorporated and the findings must be adumbrated and explained with relevance to each group of people… That way we can see where coffee is the most effective with the test subjects. But non the less if we choose to ignore the “fine print” this article gives us the justification we need to be drinking the amount of coffee we usually do without having to feel bad about it afterwards!

  4. I feel that this experiment is highly dependable on external factors, and although this experiment proves that coffee may be beneficial to your health, these external factors may not have been considered. For example, one person may prefer their coffee with no milk and one sugar, another may prefer their coffee with cream and 5 sugars, the latter being far more susceptible to contracting diabetes if they were to increase their coffee consumption, thereby also increasing their sugar consumption. Although the experiment states that one coffee would be taken with a little milk and sugar, realistically this would not apply to a diverse group of people who have different preferences and tastes. Increasing the daily amount of coffee may be beneficial in the long-run, however, there are many other short-term and long-term effects which do not benefit the body. Coffee is a diuretic substance, and the amount of times that one urinates increases and this leads to dehydration a lot of times. Coffee, which is essentially used for its caffeine, can be addictive. Coffee is linked to insomnia and poor sleeping patterns. Caffeine has also been linked to an increase in high-blood pressure and hypertension, incontinence, as well as various studies which have suggested that caffeine is linked to a 27% increase in infertility. Although this article proves one long-term benefit of increasing ones daily coffee consumption, the other short-term and long-term harmful effects should rather be taken into consideration when deciding whether or not to increase ones coffee consumption.

  5. This is an interesting discovery but I feel like it could be quite an odd one. Coffee has been found to lower risk for diabetes but there are also health risks involved in coffee consumptions especially in high quantities. This study shows that about 2 cups may reduce risk for diabetes but some people may feel that if they use it excessively their risk for diabetes may be even less. This may cause adverse side effects due to excessive consumption such as anxiety and even heart problems. Some studies have shown that unfiltered coffee has potential risk for high cholesterol, however more studies need to be done to show this. The fact that coffee may decrease risk for diabetes is a promising discovery but I feel more research should be done the effects of increasing coffee consumption and pros and cons should be weighed out to determine whether increasing coffee consumption is more beneficial or more harmful to an individual.

  6. This is an interesting discovery but I feel like it could be quite an odd one. Coffee has been found to lower risk for diabetes but there are also health risks involved in coffee consumptions especially in high quantities. This study shows that about 2 cups may reduce risk for diabetes but some people may feel that if they use it excessively their risk for diabetes may be even less. This may cause adverse side effects due to excessive consumption such as anxiety and even heart problems. Some studies have shown that unfiltered coffee has potential risk for high cholesterol, however more studies need to be done to show this. The fact that coffee may decrease risk for diabetes is a promising discovery but I feel more research should be done the effects of increasing coffee consumption and pros and cons should be weighed out to determine whether increasing coffee consumption is more beneficial or more harmful to an individual.

  7. If something sounds too good to be true it is most probably too good to be true . I agree with Karlien too much of something can not be good either. How caffeine affects the blood pressure is not fully known. Some people say that it blocks a hormone that keeps your arteries open and other speculate that the increase of your blood pressure is because the caffeine causes the adrenal glands to release more adrenaline. I think people who regularly drink caffeinated beverages develop some sort of tolerance to it because there are no long term effect on their blood pressure, were as stronger blood pressure increasing effects is to be expected on people who does not drink caffeine regularly. Most of the side effects caused by caffeine like sleeping problems , stomach ulcers , irregular heart rhythms , chronic headaches and high blood pressure are more likely seen by people who does not drink caffeine regularly. I think at this stage with more medical based research too be done by scientist and doctors will later lead to a more detailed answer on how and if caffeine could or could not lower your chances of type two diabetics. Here is a link for more on the side effects and tips too keep in mind: http://www.symptomfind.com/nutrition-supplements/side-effects-of-too-much-caffeine/

  8. As a coffee lover, I find this to be exciting news. In addition I have several diabetics in my family and knowing that coffee may reduce type 2 diabetes risk is rather reassuring.

    The article does not clearly state whether or not caffeine is the cause for the findings, however, it is probable that it is a contributing factor. In addition research done by the Harvard School of Public Health has found that caffeine has other benefits such helping to prevent diseases like stroke and certain cancers and lowering the risk of Parkinson’s and dementia. Thus it might not be such a stretch to assume that caffeine is the cause for lowering the risk of type 2 diabetes. Although, it is worth noting that the article mentions that a change in caffeinated tea consumption was not associated with changes in risk for type 2 diabetes. Perhaps the levels of caffeine in the tea were too low to have an effect.

    In response to Letlhogonolo 14065224’s comment, the article mentioned that a cup of coffee was defined as “eight ounces, black, or with a small amount of milk and/or sugar” so the amount of sugar is not the issue here.

    It’s reassuring to know that my three cups of coffee a day might actually benefit me in some medical way, besides just tasting amazing. As with most things in life, moderation is key so if you stick to below 300mg of caffeine a day the effects of coffee are likely to only be beneficial.

  9. I absolutely beg to differ with what has been said. i find it weird for a cup of tea to reduce the risk of diabetes type 2. why? simply because when you drink coffee, it is your choice to put in as many spoons of sugar as you want. thus i find it somehow contradictory. since type two is determined by our lifestyles, i believe maybe caffeine would work on its own and not neccesarily in a cup of tea.

    I am diabetic, but with type 1.I do drink coffee but believe me even if i use canderel, the blood sugar goes up.

  10. Caffeine has so many adverse effects on the body that it almost negates its use in decreasing the risk of type 2 diabetes. I have read that Caffeine contains a large amount of chemicals including polycylic aromatic hydrocarbons(carcinogens). Because it contains aldehydes and sulphides it can be taxing on your liver and kidneys to remove it. Caffeine can also reduce the effectiveness of your prescription drugs. It fights against your immune system and can turn it against you resulting in Auto immune disease which is responsible for Lupus, Rheumatoid Arthritis and muscular dystrophy and fibromyalgia.
    Needless to say caffeine raises dopamine levels and can become highly addictive. It has an adverse accumulative long term effect. As the study points out, there are other factors that decrease the risk of type 2 Diabetes. I feel that losing weight, increasing activity, not smoking, eating correctly and controlling meal portions and regular monitoring, will be more beneficial in every way to the body without increasing the risks of other diseases as an increase in caffeine intake is likely to do.

  11. Coffee is quite the treat for a lot of people. To know that there could be benefits to drink a cup or two more will definitely make them very happy!

    The thing they should keep in mind is that there is always something as too much. There is also the other factors like amounts of sugar and milk.

    It would be interesting to know exactly how it works to help prevent type 2 diabetes. What is it in the caffeine that could have such a variety of side-effects but yet something else could be prevented… It is a mystery!

    But how does this caffeine intake affect the rest of the body and a person’s health? It might reduce the risk of type 2 diabetes but at what cost would that be?

  12. This article is very interesting and relatable since coffee is such a big part of our society, even for those of us who don’t drink it. We constantly see, smell and hear about coffee.
    Considering the health benefits of drinking coffee it is very hard to generalize since everyone takes their coffee differently. People who take more sugar in their coffee increase their risks for type 2 diabetes, negating the coffee’s effect of decreasing it. like 14068720 I am also interested in what happens on a molecular level in coffee that leads to this decreased risk for type 2 diabetes. I disagree with 14111561 on that the caffeine doesn’t have an effect. This does not seem to be the case as the article states that decaffeinated coffee and caffeinated tea had no effect on the diabetes risk. This implies that the caffeine only has an effect on the coffee. Perhaps it has something to do with the interaction between caffeine and other substances found in coffee.

  13. In today’s world, many people rely on caffeine to get them through the day. In my case – I’m a huge coffee lover. In the morning, the afternoon, just before bed, whenever there is a chance I’ll make myself a warm cup of coffee. I’ve done some research in the past about the effects that too much caffeine has on a person’s health. Things like difficulty sleeping, headaches and anxiety popped up. But these “side effects” can easily be treated, and besides, I never had any of those problems. So my opinion is that we can still enjoy a cup of coffee or two a day, just don’t overdo it. Studies shows that 3 cups a coffee a day is the maximum one person can take in. And then, the fact that coffee reduces the risk of type 2 diabetes is also a plus! “To me, the smell of fresh-made coffee is one of the greatest inventions”, Hugh Jackman – I’m sure all the coffee lovers would agree.

  14. I for one am a great lover of all things coffee. I believe coffee can have some great benefits if used in moderation. “Too much of a good thing” they say. I have reaped some of the benefits of (my excessive) coffee consumption over the years. I have more energy available to me after a good cup of coffee and I also read that it somewhat prevents your eyesight from deteriorating in another post. Here is the link : https://scienceblog.com/72093/a-cup-of-coffee-a-day-may-keep-retinal-damage-away/
    All in all I will continue to enjoy my coffee consumption and reap the benefits it has to offer.

Comments are closed.