Does Caffeine Raise Blood Sugar Levels?

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With an estimated 100 million Americans suffering from diabetes or prediabetes and 64% of American adults drinking coffee everyday, it is little wonder that more people are interested in the effect that caffeine has on blood sugar levels.

Before we start looking at caffeine levels, let’s find out a little more about diabetes.

Blood Sugar Levels and Diabetes

Diabetes is a lifelong condition caused by a person’s blood sugar levels to becoming too high.

Our blood sugar is controlled by a hormone called insulin.

The structure of insulin
This is the hormone insulin (source). 

Insulin moves blood sugar (or glucose) out of our blood and into our cells where it is turned into energy.

Diabetes is caused by a lack of insulin in the body or when the insulin does not work properly.

Next, we will explore how caffeine affects our blood sugar.

Does Caffeine Raise Blood Sugar Levels?

The answer to this question is a very important one to a person with diabetes or even prediabetes as they look at making changes to their diets.

A prediabetic person is someone who has higher than normal blood sugar levels and who will become diabetic within five years. 

Caffeine can raise blood sugar levels in some people (source). 

For people who don’t have diabetes, although caffeine acts as a “pick me up”, it does not raise their blood sugar levels.

However, there is a growing body of evidence that diabetics react to caffeine differently.

And that caffeine can raise their blood sugar levels because of the way it reacts with insulin.

Having looked at the relationship between blood sugar and caffeine, in the next section we take a closer look at insulin.

Does Caffeine Raise Insulin Levels?

Not at all, in fact it seems the opposite is true.

Although the research is not conclusive by any means, it seems that caffeine causes insulin to react more slowly to raised blood sugar levels.

Insulin that is high on caffeine moves less glucose out of our blood and into our cells than if there was no caffeine.

And that for a diabetic is a very worrying finding.

But here’s a strange thing.

Caffeine can be dangerous to people who have diabetes but it can also potentially stop a person developing the disease.

And in the next section we will find out why.

Coffee and Diabetes Prevention

Numerous studies have shown that coffee drinkers are less likely to develop type 2 diabetes than non coffee drinkers.

Type 2 diabetes or “lifestyle diabetes” is a type of diabetes that is often linked to people who are overweight.

It is when the body does not produce enough insulin or when the cells in the body do not react to insulin.

A 2009 study showed that people who consumed three or more cups of coffee (or tea) a day were 40% less likely to develop type 2 diabetes.

And a study of healthcare professional published in 2014 highlighted that those who increased the amount of coffee that they drank were 11% less likely to develop type 2 diabetes.

Moving onto the next section, it is time to calculate how much caffeine coffee contains.

How Much Caffeine Does Coffee Contain?

Trying to answer this question is as difficult as answering the question “how long is a piece of string?” because there are so many different factors.

But let’s try and keep it simple…

The average 8 oz. (or 227 ml)  cup of filter coffee contains around 95 mg of caffeine and that a single shot of espresso or espresso based drink will have just over 60 mg of caffeine in them.

We also know that lighter roasts have a higher caffeine content than darker roasts.

And, coffee bought in coffee shops contains more caffeine than the coffee we make at home.

Staggering, right?

This is because commercial brands of coffee have a higher caffeine content than the brands that we drink at home.

Not only that, but the typical size of a cup of coffee bought in a shop is larger than the size of a cup that we drink and home.

Go figure….

And in our closing section, I want to provide some advice to coffee loving diabetics so that they can still enjoy drinking coffee whilst at the same time keeping themselves safe.  

How To Drink Coffee Safely

The safest advice for people with diabetes is to drink decaffeinated coffee.

Although decaf coffee isn’t totally caffeine free- it should have at least 97% of the caffeine removed.

And diabetics who love their speciality coffees need to be careful as well.

Especially as in 2017, 41% of adults in the US were drinking at least one everyday.

Specialty coffees are espresso based drinks such as lattes or cappuccinos and iced or frozen blended coffees.

These coffees come laced with a range of sugar rich syrups or contain large portions of milk which are calorie rich and contain carbohydrates.