Quick answer
Celiacs need to avoid gluten, which is found in wheat, barley and rye. Glucose syrup that is made from these grains contains gluten and is not safe for celiacs. However, some glucose syrups are made from corn or tapioca which are naturally gluten-free. Celiacs need to check the source and ensure the glucose syrup is certified gluten-free before consuming it.
What is glucose syrup?
Glucose syrup, also sometimes called corn syrup, is a sweetener made from starch. The starch is broken down into glucose molecules using enzymes or acids. The end result is a thick, sweet syrup.
Glucose syrup has a variety of uses as a sweetener in foods. It can be used in baked goods, candy, ice cream, jams, jellies, and more. It helps retain moisture in products and prevents crystallization of sugar.
Where does glucose syrup come from?
Glucose syrup can be made from different starch sources:
- Corn – Most glucose syrup in the U.S. is made from corn starch.
- Wheat – Glucose syrup can also be made from wheat starch.
- Barley – Some glucose syrups use barley as the starch source.
- Rice – Rice starch can also be used to produce glucose syrup.
- Tapioca – Tapioca from cassava root is used to make some glucose syrups.
- Potato – Potato starch is sometimes used to make glucose syrup.
The source of the starch determines whether the resulting glucose syrup is gluten-free or not.
Why celiacs need to avoid gluten
Celiac disease is an autoimmune disorder where the body is intolerant to gluten. When someone with celiac disease eats gluten, it triggers an immune response that attacks and damages the small intestine. This can lead to a variety of digestive symptoms and problems absorbing nutrients.
The only treatment for celiac disease is strictly following a gluten-free diet by avoiding all foods and ingredients that contain gluten. Even tiny amounts of gluten can provoke an immune reaction.
Gluten is a protein composite found in wheat, barley and rye. Many common foods contain these gluten-containing grains:
- Breads
- Pasta
- Cereals
- Beer
- Cakes and cookies
In addition to avoiding obvious sources of gluten, celiacs also need to watch out for hidden sources in processed foods, sauces, dressings and even non-food items like medications. Reading labels carefully and looking for “gluten-free” certifications can help identify foods that are safe to eat.
Is glucose syrup gluten-free?
Whether or not glucose syrup contains gluten depends on the original starch source:
- Corn glucose syrup is gluten-free since corn does not contain gluten.
- Wheat glucose syrup contains gluten and is not safe for celiacs.
- Barley glucose syrup also contains gluten.
- Glucose syrup from rice, tapioca, potatoes, and other gluten-free starches will be gluten-free.
So celiacs need to check the source of the glucose syrup and avoid ones made from wheat, barley or rye.
Many glucose syrups only say “glucose syrup” or “corn syrup” on the ingredient list. The only way to know for sure that it is gluten-free is if it has a gluten-free certification or contacts the manufacturer to ask about the starch source.
Are corn syrup and glucose syrup the same thing?
In the United States, the terms “corn syrup” and “glucose syrup” are often used interchangeably to refer to a sweetener made from corn starch. However, they are not technically identical products:
- Corn syrup is 100% glucose syrup made from corn starch.
- Glucose syrup can also be made from other starch sources besides corn.
So while corn syrup is always gluten-free, glucose syrup may or may not be depending on its source. Celiacs need to verify the starch source when seeing “glucose syrup” on an ingredient list.
In some other countries like the UK, glucose syrup and corn syrup are considered different ingredients. Glucose syrup can come from wheat while corn syrup only comes from corn. Always check the source, even if it’s called “corn syrup”.
What about dextrose and maltodextrin?
Dextrose and maltodextrin are other ingredients derived from starch that celiacs may encounter:
Dextrose
Dextrose is chemically identical to glucose. It is 100% pure glucose while glucose syrup is only around 20% glucose.
Like glucose syrup, dextrose can come from corn, wheat or other sources. Celiacs need to verify the starch source.
Maltodextrin
Maltodextrin is also derived from starch. It is commonly made from corn, wheat, potato or rice starch.
Maltodextrin from wheat contains gluten while maltodextrin from corn, rice or potato does not contain gluten.
Again, celiacs need to check the source or look for gluten-free certification when seeing maltodextrin on an ingredient list.
What about barley malt?
Barley malt is malted barley that has been allowed to germinate. This activates enzymes that break down starches into sugars. Barley malt is used to make beer and whiskey, and it also appears as an flavoring in some foods.
Since barley malt comes from barley grain, it contains gluten and is not safe for celiacs. They need to avoid any foods with barley malt or malt extract as an ingredient.
Should celiacs avoid oats?
Oats are naturally gluten-free, but they are often contaminated with gluten grains like wheat during growing and processing.
Some celiacs are also sensitive to the protein avenin in oats. For these reasons, traditional oat-based foods like oatmeal and muesli are not recommended on the gluten-free diet.
However, some oat products are certified gluten-free and safe for most celiacs as long as they are tolerated. These include some oat milks, oat flours and gluten-free oatmeal.
Celiacs should discuss oat products with their doctor or dietitian before introducing them, even if certified gluten-free. Symptoms should be monitored closely.
What about wheat starch?
Wheat starch, also called wheat flour, is isolated starch extracted from wheat grain. Although it comes from wheat, wheat starch contains very minimal gluten since most of the protein has been removed.
In some countries like Europe, wheat starch is considered gluten-free. However, in North America wheat starch is still regarded as unsafe for celiacs. There isn’t consensus among experts yet whether traces of gluten in wheat starch are harmful or not.
Until more research confirms it’s safety, celiacs should continue avoiding products with wheat starch in North America.
Tips for finding gluten-free glucose syrup
Here are some tips for celiacs to find glucose syrup that is gluten-free:
- Look for glucose syrup made from corn, tapioca, rice or potato starch.
- Avoid glucose syrup that doesn’t specify the starch source.
- Check for gluten-free certifications from organizations like the GFCO.
- Call or email manufacturers to inquire about the starch source if uncertain.
- Be extra cautious with imported glucose syrups that may use wheat starch.
Many large brands of glucose syrup sold in the U.S., like Karo corn syrup, are made from corn and gluten-free. But it’s still important to verify since manufacturing can change. Smaller or imported brands are more likely to use wheat starch.
Are there health issues with corn syrup?
High fructose corn syrup has gotten a bad reputation in recent years over potential links to obesity, diabetes and other health issues. However, regular corn syrup and glucose syrup don’t contain fructose and don’t carry the same concerns.
Corn syrup and glucose syrup are broken down into glucose during digestion. They don’t contain more calories or sugar than table sugar (sucrose).
But there are a couple drawbacks of corn syrup to keep in mind:
- It offers less sweetness than sucrose. More corn syrup is needed in recipes to achieve the same level of sweetness.
- It lacks nutritional value. While sugar also has no nutrients, glucose syrup doesn’t even contain antioxidants that raw cane sugar provides.
Overall, glucose syrup made from corn and other gluten-free sources is considered safe for celiacs in moderation as part of an overall healthy diet. It can provide a helpful substitute to use in place of gluten-containing ingredients. But other natural sweeteners like fruit or maple syrup may be more nutritious options.
Gluten-free substitutes for glucose syrup
Celiacs have a few options for substituting glucose syrup in recipes:
Honey
Honey provides sweetness and moisture similar to corn syrup. Replace 1 cup of corn syrup with about 3/4 to 1 cup of honey. Honey is sweeter so start with less and adjust to taste.
Molasses
Molasses adds rich, deep sweetness and color. Use about 3/4 cup molasses in place of 1 cup corn syrup.
Brown rice syrup
Brown rice syrup is made from brown rice and is gluten-free. It has a mild caramel-like flavor. Substitute 1 cup of corn syrup with 1 cup brown rice syrup.
Fruit purees
Applesauce and pureed prunes can work in some baked goods. Use about 1/2 to 1 cup for every 1 cup of glucose syrup. May need to reduce baking temperature 25 degrees F.
Granulated sugar
A blend of sugar and liquid can approximate the texture of corn syrup in some recipes. Use 1 cup sugar + 1/4 cup liquid for 1 cup glucose syrup.
Always check that substitutes work for the recipe. Cookies and some candies may not hold together as well without glucose syrup. Granulated sugar doesn’t work as well in frozen desserts.
Is golden syrup gluten-free?
Golden syrup is a thick amber-colored syrup that has a light caramel flavor. It is popular in Commonwealth countries, especially the UK.
Traditional golden syrup is made from sugar cane and does not contain gluten. Brands like Lyle’s Golden Syrup are gluten-free and safe for celiacs when uncontaminated.
However, some golden syrups are made with wheat glucose syrup instead of cane sugar. These would contain gluten and be unsafe.
Celiacs should read ingredients carefully since “golden syrup” alone doesn’t indicate if it’s made from wheat or cane sugar. Contact manufacturers if unsure.
Glucose syrup in medications
In addition to being added to foods, glucose syrup can be found in some oral medications as an inactive ingredient. It is used as a thickener, filler, sweetener or preservative.
Celiacs need to be cautious with medications containing glucose syrup. As with foods, the glucose syrup source needs to be confirmed as gluten-free for it to be safe.
Luckily, many drug companies are aware of gluten concerns. Medication labels may specify “corn-derived” glucose syrup. But when in doubt, celiacs should contact the manufacturer directly to verify.
Bottom line
Celiacs can consume glucose syrup as long as it is made from gluten-free starch sources like corn, tapioca, rice or potatoes. They need to avoid glucose syrups derived from wheat, barley or rye starch which contain gluten.
Carefully reading ingredient lists and looking for “gluten-free” labels can help identify safe options. When the starch source is unclear, contacting the food or drug manufacturer provides the only way to confirm gluten-free status.
With vigilance, celiacs can use glucose syrup to help recreate the texture and sweetness of foods requiring wheat-based ingredients. While not the most nutritious choice, glucose syrup from gluten-free sources is a helpful occasional treat as part of an otherwise strict gluten-free diet.
