Not All Sugars Are the Same: Using Glucose to Treat Hypoglycemia


Editor’s Note: Low blood sugars—also known as hypoglycemia—can be one of the most challenging, stressful and often scary parts of living with diabetes. If you take insulin or other medications that can cause lows, learning how to prevent and treat them is very important.

  • Treating low blood sugar: If your blood sugar is below 3.88 mmol/L70 mg/dL and you are able to drink or chew, treat with 15 grams of fast-acting carbohydrates. Wait 15 minutes, check your blood sugar, then treat again if your blood sugar is still low.
  • Severe low blood sugar: If your blood sugar is below 3.0 mmol/L55 mg/dL and you are unable to drink or chew fast-acting carbohydrates, someone may need to call 911 and administer emergency glucagon.

If you could relieve the symptoms of low blood sugar sooner and faster—would you?

We’re generally told to eat 15 grams of fast-acting carbohydrates when treating a low blood sugar—but one type of sugar is truly the fastest.

While being prepared for low blood sugar emergencies with fast-acting carbohydrates is the goal, we’ve all found ourselves low at times when we have to use less-than-ideal foods.

Here, we’ll discuss why treating low blood sugars with glucose (dextrose) is the fastest way to raise your blood sugar.

Glucose vs. Fructose vs. Sucrose

There are several very good reasons why glucose tabs are encouraged over a bowl of ice cream or even a handful of grapes when it comes to treating low blood sugar. While the fat and protein in that ice cream slow down the digestion of the sugar, the type of sugar in any carbohydrate source matters, too.

Here are the three main types of sugar found in food:

  • Glucose/Dextrose: Raises blood sugar levels immediately because it is already in the form of sugar your brain and cells recognize and require for fuel
  • Fructose: Does not actually breakdown into glucose and raises your blood sugar, because fructose must be metabolized by the liver
  • Sucrose: Known as a “double sugar” because it’s made of equal parts of glucose and fructose, which means only half of its contents can raise blood sugar

Let’s take a closer look at these three types of sugar and their impact on your next low blood sugar.

Glucose / Dextrose

Glucose—also known as dextrose—immediately raises blood sugar levels. Unlike sucrose or fructose, glucose is already in a form your body can use, making it the most rapidly-absorbed source of carbohydrate you can choose.

The faster you can raise your blood sugar, the sooner you can calm down the uncomfortable (and often scary) symptoms of low blood sugar.

  • Sources of 100 percent glucose include: Dex4 glucose tabs, glucose gel, Smarties, Pixie Stix

When you choose these sources of carbohydrate to treat a low, your blood sugar will likely rise significantly faster than choosing a piece of fruit, a juice box, a candy bar, or even a spoonful of honey.

That being said, there are some plant-based foods that contain more glucose than others—including grapes, cherries, honey and corn syrup (not to be confused with high fructose corn syrup).

If you’ve ever wondered why a bowl full of raspberries has such a lower impact on your blood sugars than the same amount of carbohydrates from a bowl of grapes, it’s all about the amount of glucose vs. fructose vs sucrose.

For example, here’s the breakdown of different types of fruit.

Fruit (100 grams) Glucose grams Fructose grams Sucrose grams
apple 2.3 7.6 3.3
banana 4.2 2.7 6.5
blackberries 3.1 4.1 .04
blueberries 3.5 3.6 0.2
cherries 8.1 6.2 0.2

*Look at the different sugar contents of more fruits in this table.


Fructose is found naturally in most plant-based foods, we think of these as naturally healthy sources of carbohydrates. Unfortunately, they actually aren’t ideal for treating low blood sugars.

  • Sources of fructose include: fruit, honey, agave, juice, pasta, bread, veggies and many more processed foods

The problem is that fructose on its own does not actually break down into glucose to raise your blood sugar. Instead, fructose is first metabolized by the liver and can raise triglyceride levels and promote fatty liver when consumed in large amounts. Diets high in fructose are also associated with higher levels of belly fat. (This is specifically why “high fructose corn syrup” is a concerning ingredient in many processed foods.)

Of course, we all know an apple raises your blood sugar—this is because most foods that contain fructose also contain varying amounts of glucose and sucrose.

If you use an apple or even a juice box to treat low blood sugar, only a percentage of the carbohydrates in that apple are going to raise your blood sugar. Your body also has to break down the fibrous apple in order for the sucrose and glucose it contains to reach your bloodstream. This takes longer than using a glucose tab where the digestion process is nearly instant.

Choosing carbohydrates that contain a great deal of fructose for low blood sugars also means you’re consuming calories that are not helping you. Treating frequent low blood sugars with more calories than you need can make it more challenging to manage your personal weight goals and lead to gradual weight gain.


Sucrose is a “disaccharide” or “double sugar” because it contains equal parts of glucose and fructose.

  • Sources of sucrose include: white/brown sugar, turbinado sugar, maple syrup, jelly beans, gummies and more processed candies/snacks

This means half of the carbohydrates in a packet of white sugar will raise your blood sugar quickly and the other half will be metabolized by your liver.

While fast-acting carbohydrates containing sucrose are obviously the best option if it’s the only option you have, being prepared with glucose-containing carbohydrates means raising your blood sugar sooner and faster.

The bottom line

Low blood sugars are a real part of living with diabetes—especially if you take insulin. Being prepared for low blood sugars comes down to having fast-acting carbohydrates in all the right places. The fastest carbohydrate—glucose tabs or glucose gel—are easy to store in your car, your purse, your nightstand, your gym bag, your desk and your winter coat because they don’t freeze, melt, or rot.

If you’re tired of waiting for the carbohydrates in a granola bar or a bag of gummies to raise your blood sugar, it might be time to take a closer look at the types of sugar in the foods you’re choosing to treat lows.

Educational content related to diabetes management is made possible with support from ​Dex4, an active partner of Beyond Type 2 at the time of publication. ​Editorial control rests solely on Beyond Type 2.

WRITTEN BY Ginger Vieira, POSTED 05/26/22, UPDATED 01/10/23

Ginger Vieira is the senior content manager at Beyond Type 1. She is also an author and writer living with type 1 diabetes, celiac disease, fibromyalgia and hypothyroidism. She’s authored a variety of books, including “When I Go Low” (for kids), “Pregnancy with Type 1 Diabetes,” and “Dealing with Diabetes Burnout.” Before joining Beyond Type 1, Ginger spent the last 15 years writing for Diabetes Mine, Healthline, T1D Exchange, Diabetes Strong and more! In her free time, she is jumping rope, scootering with her daughters, or walking with her handsome fella and their dog.