Drinking Coffee with Diabetes: Does It Help or Harm?

Is your java habit good or bad for blood sugar? Here’s what endocrinologists want you to know.

Is coffee healthy to drink when you have diabetes? A Google search can be confusing. For one thing, many studies point out that drinking coffee may reduce your diabetes risk; other headlines discuss whether coffee can spike blood sugar once you’re diagnosed with diabetes. So we talked to endocrinologists and took a closer look at the research to understand coffee’s role in managing type 2 diabetes.

Before Diabetes: Can Coffee Reduce Your Risk?

Perhaps the best news for coffee drinkers worried about their diabetes risk is this 2005 JAMA review: After researchers analyzed data from nine separate studies on more than 193,000 participants, they concluded that regular coffee drinking was associated with a lower risk of developing type 2 diabetes. But was the coffee itself or the caffeine responsible for the benefits?

“In various studies, as coffee and tea consumption increases, the risk of diabetes decreases,” says Caroline Messer, MD, an endocrinologist at Lenox Hill Hospital. Subjects who drank six cups of coffee daily were at lower risk for diabetes than those who drank less than two cups of coffee per day. This phenomenon was observed for both caffeinated and decaffeinated beverages. This suggests that caffeine may not be the only driver behind the improvement in blood sugar levels among java lovers.

Drinking coffee was associated with a lower risk of developing type 2 diabetes.

A 2016 study published in the International Journal of Pharmacy and Pharmaceutical Sciences concluded that caffeine along with chlorogenic acid, a strong antioxidant found in coffee, improves insulin sensitivity and lowers levels of uric acid and sugar in the body. (Insulin sensitivity, by the way, is a good thing. It means your body is more responsive to both naturally produced insulin and injected insulin.) Too much uric acid in the blood can lead to insulin resistance and increased risk of diabetes. The study only included coffee, not tea, which implies there are certain components of coffee beyond caffeine that improve insulin sensitivity.

After Diabetes: Can Coffee Raise Your Blood Sugar Levels?

If you are a regular coffee drinker and have been recently diagnosed with diabetes, you may notice a spike in your blood sugar levels after you down your morning latte. For some people with diabetes, caffeine can simulate a stress response that releases sugar from the liver, raising blood sugar levels. But that doesn’t necessarily mean you have to give up your cuppa brew. First of all, caffeine can affect people differently, so just because it sends your friend’s blood sugar skyrocketing doesn’t mean it will do the same to yours.

“If there is a question about the coffee’s relationship to a rise in blood glucose, I have patients wear a continuous glucose monitoring device and we can watch the glucose response to the coffee,” says Stuart Weiss, MD, clinical assistant professor of endocrinology at NYU Langone Health.

If you don’t have a continuous glucose monitor, test blood sugar levels before and after you drink coffee and keep a record to show your doctor. Before you take your first sip in the morning, Dr. Weiss recommends you drink a glass of water first. “Being well hydrated helps to modulate the rise seen in glucose.”

Tips for Healthy Coffee Drinking with Diabetes

Diabetes educators Lisa Muras, RD, and Nadine Jakim Young, RD, run clinics to help people lower their A1C at the Virginia Hospital Center, in Arlington, Virginia. Here, check out their tips to savor your next cup.

  • Watch your added sugar: Brewed black coffee has no carbohydrates, but adding sugar (white, brown, raw—any kind) will add 15 grams (equivalent to 1 carbohydrate serving) per tablespoon. If you need your coffee to taste a little sweet, use a sugar substitute instead to sweeten your brew.
  • Skip the half-n-half: Half-n-half adds around 40 calories per 2 tablespoons and 1 gram of carbohydrate, but consider the fat at 3.5 grams if you’re heavy on the pouring. Fat-free half-n-half may seem like a good alternative, but it has more sugar than the regular version!
  • Swap out cow’s milk: Any type of cow’s milk (whole, 2%, 1%, skim) still adds carbohydrates. Try unsweetened almond or soy milk for fewer carbs, especially if you like more milk in your joe.
  • Steer clear of syrups: Specialty coffee drinks such as mocha lattes and frappes are high in sugar. Ask for sugar-free syrup, no whipped cream and the smallest size available for fewer carbs and calories.
  • Get fancy with your own frother: Make your own mocha latte at home with an inexpensive frother. Add 2 teaspoons of cocoa powder to your half-cup of coffee. Heat ⅔ cups of unsweetened almond, soy, or coconut milk. Use a frother to create foam and pour it over the coffee. Sweeten if needed with sugar-free sweetener.
  • Get spicy: Try cinnamon or nutmeg in your coffee instead of adding sugar for a flavor boost.
  • Limit caffeine: Stay under the recommendation of three to five cups (or 400 milligrams of caffeine) of coffee per day. Too much caffeine can raise blood sugar in some people. Don’t forget caffeine can be found in products other than coffee such as soda, tea, chocolate and even some medications.
  • Drink water first: Before you hoist an additional mug of coffee, make sure you’re hydrated first. Use the pee color test. Your urine should be light yellow to straw-colored, not amber or honey-colored.