Coffee and Diabetes – Benefits of Coffee & Effect on Blood Sugar

Coffee is one of the most popular and widely consumed beverages worldwide.

In fact, it is the second leading beverage in the world, second only to water.

Coffee trade accounts in the US for $10 billion worldwide! This is mostly because of coffee’s delicious aroma and taste. But did you know it can also have beneficial effects on your health? Particularly on your blood sugar levels?

Coffee is a complex mixture of more than 800 different volatile compounds. The most common compounds in coffee are caffeine and chlorogenic acids. Coffee also contains caffeic acid and hydroxyhydroquinone (called HHQ for short). It also has other phytochemicals such as alkaloids, phenolic compounds, vitamins, carbohydrates, lipids, minerals, and nitrogenous compounds.

Coffee has multiple properties as a food additive and nutraceutical. Caffeine seems to exert its benefits by antagonizing the adenosine receptors. Historically, coffee was not always shown in the positive light it is today. Now that we know more about coffee’s pharmacology, we can see it for its potential health benefits.

Get Your FREE Diabetes Diet Plan

  • 15 foods to naturally lower blood sugar levels
  • 3 day sample meal plan
  • Designed exclusively by our nutritionist

By clicking “Download Now”, I agree to Ben's Natural Health Terms and Conditions and Privacy Policy.

Coffee and prevention of diabetes

There is a notably lower risk of type 2 diabetes among people who drink coffee. There is mounting evidence to show that there is a lower risk of developing type 2 diabetes by those who drink three to four cups a day.

This is likely due to the presence of chlorogenic acids and caffeine. These two compounds are higher in concentration after the roasting process. Coffee also contains magnesium and chromium. Greater magnesium intake has been linked with lower rates of type 2 diabetes. The combination of magnesium and chromium can help improve insulin sensitivity.

One meta-analysis study looked at 28 different studies with 1,109,272 participants. Of these, 45,335 type 2 diabetes patients. This meta-analysis found an inverse association between high coffee consumption and low risk of type 2 diabetes in a dose-dependent manner. This means that the more coffee they drank, the lower their chances of developing type 2 diabetes. This was true of both caffeinated coffee and decaffeinated coffee.

A different study from 2009 looked at 40,000 participants. They found that consuming three cups of coffee or green tea per day led to a 40% lower risk of developing type 2 diabetes.

One study looked at healthcare professionals in both the US and the UK. This 2014 study found that those who increased their coffee consumption had an 11% decrease in type 2 diabetes risk over the following four years. 

A Harvard study looked at over 100,000 people over 20 years. They found that people who increased their caffeine intake by more than one cup per day had an 11% lower risk of developing type 2 diabetes. People who reduced their coffee intake by one cup per day increased their risk of developing diabetes by 17%.

Coffee’s effect on glucose and insulin

Coffee affects glucose homeostasis. It has antioxidant activity and anti-inflammatory activity. This is mostly due to compounds such as chlorogenic acids, trigonelline, and horharman. Filtered coffee can help to reduce glucose uptake and decrease insulin sensitivity.

Coffee stimulates glucose uptake in skeletal muscle. It also increases glycogen accumulation after exercise. Over a four-week period, regular high caffeine consumption has been shown to impair insulin sensitivity in people with type 2 diabetes. Research has established a relationship between higher coffee consumption and lower insulin sensitivity.

One study looked at an intravenous injection of caffeine in rats. Caffeine increases phosphorylation of adenosine monophosphate-activated protein kinase (called AMPK for short). It also increases the phosphorylation of acetyl CoA carboxylase (called ACC for short). Caffeine also increased glucose transport. Cafestol and caffeic acid increased insulin secretion in rat beta cells. It can also increase glucose uptake into human muscle cells.

A further study looked at the association between green coffee extract and fasting blood glucose. This was a meta-analysis of six articles. Results showed that green coffee extract supplementation reduced fasting blood glucose levels by 0.32 on average. If the green coffee extract was given at a dose larger than 400 milligrams, there was also a significant decrease in HOMA-IR. HOMA-IR is a marker of insulin resistance. Researchers concluded that green coffee extract intake could be linked with fasting blood glucose improvement.

Another study looked at 17 healthy men. These men participated in five trials each. During these trials, they consumed either coffee, decaf coffee, or water. After one hour of the intervention, they received an oral glucose tolerance test. Researchers then observed the effects on glucose metabolism. Insulin activity was higher with decaf than with water. Researchers concluded that consuming decaf coffee improves insulin sensitivity.

One study looked at the effects of decaf green coffee bean extract on glycemic control and insulin resistance in patients with metabolic syndrome. Researchers randomized the subjects to consume 400 milligrams of green coffee extract or placebo twice a day for eight weeks.

The treatment group had significantly lower fasting blood glucose compared to the placebo. It went down by 0.28 millimoles per Litre in the treatment group. And it went up by 1.63 millimoles per Litre in the placebo group. HOMA-IR went down by 1.41 in the treatment group and up by 1.23 in the placebo group. Researchers concluded that green coffee extract could improve metabolic syndrome components such as fasting blood sugar and insulin resistance.

While coffee can be beneficial for protecting against diabetes, some studies show that coffee can pose dangers if you already have type 2 diabetes. A study in 2004 showed that taking a caffeine capsule before eating resulted in higher post-meal blood glucose in people with type 2 diabetes. It also showed an increase in insulin resistance.

According to research, genetics could be involved. Genes might affect caffeine metabolism and how it affects blood sugar. In this 2004 study, people who metabolize caffeine slower have higher blood sugar levels than those with quick caffeine metabolism.

Caffeine is well known. However, it’s not the only compound in coffee. Not by a long shot. These other compounds could be responsible for the protective effect that coffee has. Coffee drinkers who drink coffee over a long time can also change their glucose and insulin sensitivity. Tolerance from long term coffee consumption could be what exerts protective effects.

Other health benefits

Can help reduce cancer risk

Coffee has been associated with a reduced risk of various types of cancer. Two compounds, in particular, are responsible for this: cafestol and kahweol. They act as safeguards against some malignant cells by modulating the detoxifying enzymes. In particular, coffee helps prevent breast, colorectal, colon, endometrial, and prostate cancer.

Reduces oxidative stress

Coffee reduces oxidative stress because of its ability to induce mRNA and protein expression. It also helps to mediate something called the Nrf2-ARE pathway stimulation.

Can help build skeletal muscle

One study fed mice either a normal diet or a normal diet supplemented with coffee. Coffee supplementation increased skeletal muscle hypertrophy. It also unregulated protein expression of total MHC, MHC2A, and MHC2B in the quadriceps muscle. It also helped to control expression of myostatin. Coffee also modulated expression of a protein called PGC-1a. This then helped increase grip strength. These results suggest that coffee increases skeletal muscle function and hypertrophy.

Other benefits

Coffee has a whole array of other health benefits. Coffee can help with the following health conditions:

  • Hypertension (high blood pressure)

  • Cardiovascular disease (heart disease)

  • Stroke

  • Heart failure

  • Cardiac arrhythmias

  • Central nervous system

  • Focus and concentration

  • Liver disease

  • Parkinson’s disease

  • Alzheimer’s disease

  • Asthma

  • Gout

  • Gall stones

  • Depression

  • Obesity

  • Multiple sclerosis

  • Primary sclerosis cholangitis

  • Ulcerative colitis

  • Athletes’ glycogen recovery

  • Metabolic syndrome

  • Inflammation

  • Dyslipidemia (high cholesterol)

  • Microbial infections

  • Lipid peroxidation

  • Mental health

  • Suicidal risk

Risks and warnings


Pregnant women should avoid excessive coffee consumption. It can increase the risk of low birth weight and preterm labor. Too much coffee can also increase the risk of pregnancy loss, spontaneous abortion, or impaired fetal growth. A few studies also say that there is an increased risk of childhood leukemia after maternal coffee drinking during pregnancy. However, these studies are limited and inconsistent.

Autoimmune conditions

Coffee seems to increase the risk of developing rheumatoid arthritis. Additionally, it also appears to increase the risk of type 1 diabetes. It also decreases methotrexate efficacy in rheumatoid arthritis. It also decreases the absorption of levothyroxine (a thyroid medication) in Hashimoto’s disease (an autoimmune thyroid condition). Coffee can also cross-react with gliadin antibodies in patients with Celiac disease.


Many people can develop a dependency or addiction to coffee. In these people, withdrawal symptoms can be unpleasant. Withdrawal symptoms include headaches and muscle fatigue.

Coffee additives

Although coffee can have many benefits, the milk and sugar added to it can be detrimental to health. Adding syrup to coffee is a common trend but not a good idea. It’s an especially bad idea if you are one of the many diabetics in this country or are at risk of diabetes. We want you to reduce your exposure to sugar instead!

Lattes are coffee with lots of milk. They contain lots of calories and lots of carbohydrates. Many coffee shops offer “skinny latte” alternatives. However, they are made with skim milk but then sweetened. This actually raises its calorie content. And milk has about five grams of carbs per 100 grams. This is the same, whether it’s full fat or skim milk. A medium size of unsweetened skinny latte can have anywhere from 10 to 15 grams of carbs.

Keep in mind that the sugar and fat in coffee beverages can outweigh the coffee itself’s benefits! This is true of naturally sweetened coffee as well as artificially sweetened coffee. The added sweetener increases your risk of developing type 2 diabetes. Coffee based beverages high in saturated fat or sugar can add to insulin resistance. This can eventually lead to type 2 diabetes mellitus. A strong black coffee might be your best option!

Other risks and warnings

Do keep in mind that if you suddenly start drinking more coffee, this can produce an atypical response by the body.

Certain groups of people may be more vulnerable to the adverse effects of caffeine. These include the following groups of people:

  • Children

  • Adolescents

  • The elderly

  • People with hypertension

Some other side effects can occur when you drink coffee. These include the following:

  • Insomnia

  • Headaches

  • Tremors

  • Palpitations

  • Restlessness

  • Anxiety

  • Heartburn

  • Higher risk of fracture in women

  • Higher cholesterol levels

  • Increased risk of lung tumors in smokers


Coffee is a beverage beloved by many. It’s a shame it took so long for us to realize just how beneficial it can be to our health. But knowledge is power. Now that we know about coffee’s vast array of health benefits, we can use it to our advantage. Coffee consumption can help to prevent you from becoming a diabetic patient. It does this by managing glucose and insulin levels.

But it doesn’t stop there. Coffee has a wide range of other health benefits, ranging from neurodegenerative diseases to mental health concerns to autoimmune conditions.

As always, some risks and warnings do come along with this functional food. If you want to use coffee for its health benefits, it’s worth speaking to your health care provider about it. Now you can not only enjoy the taste of your morning cup of java but also reap the health rewards that come along with it!

Explore More

type 2 diabetes treatment

Can The Coffee Bean Pill Treat Type 2 Diabetes?


  1. Alicandro, G; Tavani, A & La Vecchia, C. (2017). Coffee and cancer risk: a summary overview. Eur J Cancer Prev. 26 (5), 424-32.
  2. Butt, MS & Sultan, MT. (2011). Coffee and its consumption: benefits and risks. Crit Rev Food Sci Nutr. 51 (4), 363-73.
  3. Chrysant, SG. (2017). The impact of coffee consumption on blood pressure, cardiovascular disease and diabetes mellitus. Expert Rev Cardiovasc Ther. 15 (3), 151-6.
  4. Ding, M; Bhupathiraju, SN; Chen, M; van Dam, RM & Hu, FB. (2014). Caffeinated and decaffeinated coffee consumption and risk of type 2 diabetes: a systematic review and a dose-response meta-analysis. Diabetes Care. 37 (2), 569-86.
  5. Grosso, G; Godos, J; Galvano, F & Giovannucci, EL. (2017). Coffee, caffeine, and health outcomes: An umbrella review. Annu Rev Nutr. 21 (37), 131-56.
  6. Jang, YJ; Son, HJ; Kim, JS; Jung, CH; Ahn, J; Hur, J & Ha, TY. (2018). Coffee consumption promotes skeletal muscle hypertrophy and myoblast differentiation. Food Funct. 9 (2), 1102-11.
  7. Kempf, K & Martin, S. (2010). Coffee and diabetes. Med Klin (Munich). 105 (12), 910-5.
  8. Loureiro, LM; Reis, CE & da Costa, TH. (2018). Effects of coffee components on muscle glycogen recovery: A systematic review. Int J Sport Nutr Exerc Metab. 1 (3), 284-93.
  9. Nieber, K. (2017). The impact of coffee on health. Planta Med. 83 (16), 1256-63.
  10. Nikpayam, O; Najafi, M; Ghaffari, S; Jafarabadi, MA; Sohrab, G & Roshanravan, N. (2019). Effects of green coffee extract on fasting blood glucose, insulin concentration and homeostatic model assessment of insulin resistance (HOMA-IR). Diabetol Metab Syndr. 5 (11), 91.
  11. O’Keefe, JH; DiNicolantonio, JJ & Lavie, CJ. (2018). Coffee for cardioprotection and longevity. Prog Cardiovasc Dis. 61 (1), 38-42.
  12. Rebelo, I & Casal, S. (2017). Coffee: A dietary intervention on type 2 diabetes?. Curr Med Chem. 24 (4), 376-83.
  13. Reis, CE; Paiva, CL; Amato, AA; Lofrano-Porto, A; Wassell, S; Bluck, LJ; Dorea, JG & da Costa, TH. (2018). Decaffeinated coffee improves insulin sensitivity in healthy men. Br J Nutr. 119 (9), 1029-38.
  14. Rodriguez-Artalejo, F & Lopez-Garcia, E. (2018). Coffee consumption and cardiovascular disease: a condensed review of epidemiological evidence and mechanisms. J Agric Food Chem. 66 (21), 5257-63.
  15. Roshan, H; Nikpayam, O; Sedaghat, M & Sohrab, G. (2018). Effects of green coffee extract supplementation on anthropometric indices, glycemic control, blood pressure, lipid profile, insulin resistance and appetite in patients with the metabolic syndrome. Br J Nutr. 119 (3), 250-8.
  16. Saeed, M; Naveed, M; BiBi, J; Kamboh, AA; Phil, L & Chao, S. (2019). Potential nutraceutical and food additive properties and risks of coffee: a comprehensive overview. Crit Rev Food Sci Nutr. 59 (20), 3293-3319.
  17. Santos, RM & Lima, DR. (2016). Coffee consumption, obesity and type 2 diabetes: a mini-review. Eur J Nutr. 55 (4), 1345-58.
  18. Sharif, K; Watad, A; Bragazzi, NL; Adawi, M; Amital, H & Shoenfeld, Y. (2017). Coffee and autoimmunity: More than a mere hot beverage!. Autoimmun Rev. 16 (7), 712-21.

Top Products

Total Health


Glucose Control