Gluten is a protein found in wheat, barley, and rye. It gives elasticity to dough, helping baked goods keep their shape. For people with celiac disease or non-celiac gluten sensitivity, consuming gluten triggers an autoimmune response that damages the small intestine. This can cause symptoms like abdominal pain, bloating, diarrhea, constipation, vomiting, fatigue, headache, anxiety, and more.
Cellulose is a carbohydrate, not a protein. It is the main component of plant cell walls and the most abundant organic polymer on Earth. Humans cannot digest cellulose, but it provides dietary fiber that promotes gut health. Though cellulose comes from gluten-containing grains, it does not contain gluten.
What is Gluten?
Gluten consists of two protein groups: gliadins and glutenins. When flour and water mix, these proteins link together and form elastic strands that give bread its chewy texture.
Gliadins give bread extensibility and viscosity. Glutenins provide elasticity and strength. Together, gliadins and glutenins allow dough to rise and keep its shape during baking.
Gluten is present in significant amounts in the grains wheat, barley, and rye. It is found throughout the entire grain kernel.
People with celiac disease or non-celiac gluten sensitivity cannot tolerate gluten proteins. When they eat gluten, it triggers immune system activity and inflammation in the small intestine. Over time, this can damage the gut lining and prevent proper nutrient absorption.
What is Cellulose?
Cellulose is a structural carbohydrate found in plants. It is the main component of plant cell walls. The chemical structure of cellulose is a long chain of glucose molecules bonded together.
Cellulose provides rigidity and strength to plant cells. Wood, stems, leaves, and skins of fruits and vegetables contain significant amounts of cellulose. Cotton and linen fibers are nearly pure cellulose.
Humans do not have the enzyme cellulase to break down cellulose’s beta-glycosidic bonds. Therefore, cellulose passes through the digestive system intact and humans cannot absorb many calories from it. However, cellulose provides insoluble fiber that promotes regularity and a healthy gut.
Cellulose Occurs Naturally Gluten-Containing Grains
Wheat, barley, and rye contain both gluten and cellulose. The gluten proteins are present mainly in the endosperm, which is the inner starchy part of the grain. The cellulose is in the bran, the multi-layered outer skin of the grain kernel.
During milling, the endosperm and bran are separated. Whole grain flour contains both the gluten-rich endosperm and the cellulose-rich bran. Refined white flour is milled to remove the bran and germ, leaving just the starchy endosperm.
So wheat, barley, and rye flours naturally contain both gluten and cellulose. The gluten content varies depending on the grain and flour type. Cellulose content varies based on how much bran remains after milling.
Why Cellulose Does Not Contain Gluten
While cellulose and gluten both occur in wheat, barley, and rye, cellulose itself does not contain gluten. This is because:
- Cellulose is a carbohydrate, while gluten is a protein.
- Gluten proteins are present in the endosperm. Cellulose is present in the bran.
- They have completely different molecular structures.
Gluten contains the amino acids proline and glutamine. Cellulose contains only glucose molecules.
During food processing, cellulose can be separated and isolated from gluten-containing grains. The purified cellulose contains no detectable gluten proteins.
Many people conclude that cellulose must be safe on a gluten-free diet. However, there are a few considerations when it comes to processed cellulose additives.
How Cellulose is Used in Food Products
Cellulose has various uses in food manufacturing. It can be added to products to:
- Add fiber – Powdered cellulose made from plant material acts as insoluble dietary fiber.
- Improve texture – Microcrystalline cellulose thickens, stabilizes, and improves mouthfeel.
- Assist processing – Powdered cellulose prevents sticking and clumping.
- Retain moisture – Cellulose gel, carboxymethyl cellulose, and other versions help retain water.
- Make low-calorie products – Indigestible cellulose displaces other nutrients without adding calories.
- Reduce fat – Cellulose fibers mimic some properties of fat.
On food labels, cellulose may be identified as cellulose gum, cellulose gel, carboxymethyl cellulose, microcrystalline cellulose, powdered cellulose, etc. The cellulose is typically derived from wood pulp or other plant sources.
Is Purified Cellulose Gluten-Free?
Purified cellulose made from gluten-containing grains still does not contain gluten proteins. During processing, the cellulose fibers are isolated from the grain kernels and extensively purified. No gluten proteins remain in the final cellulose product.
Many organizations consider highly-purified cellulose from wheat, barley, or rye to be gluten-free:
- Celiac Disease Foundation – States purified cellulose derived from wheat is gluten-free.
- Gluten Intolerance Group – Considers purified cellulose safe for celiac disease.
- National Foundation for Celiac Awareness – Says purified cellulose is not a concern for gluten content.
- Celiac Sprue Association – Recognizes purified cellulose as gluten-free.
- Gluten Free Watchdog – Confirms purified cellulose does not contain detectable gluten based on third-party testing.
So the consensus is that purified cellulose ingredients are considered gluten-free, even when originally derived from gluten-containing grains. Testing shows no detectable gluten proteins remaining in purified cellulose additives.
Possible Concerns with Cellulose as a Food Additive
While purified cellulose seems to be gluten-free, there are a few things those with celiac disease or gluten sensitivity should know:
- Purity and testing: Manufacturers should provide verification that cellulose additives have been purified and test gluten-free. Cellulose purity can vary.
- Source material: Cellulose derived from wheat, barley, or rye has a higher risk of gluten cross-contact than cellulose from corn, cotton, or wood.
- Allergies: In rare cases, people may be allergic to cellulose gum due to protein impurities. Cellulose made from specific gluten grains could provoke allergy symptoms.
- Fiber tolerance: Added non-soluble cellulose may exacerbate IBS symptoms in sensitive individuals who do not tolerate insoluble fiber well. It does not feed gut bacteria like soluble fiber.
So while purified cellulose additives are likely safe from a gluten standpoint, they may present other concerns for some people considering individual factors.
Checking Food Labels for Cellulose
When a food contains added cellulose, it must be included in the ingredient list on the label. However, the specific source of the cellulose does not need to be identified.
Here are some tips for evaluating cellulose in food products:
- Look for words like “cellulose gum,” “cellulose gel,” “microcrystalline cellulose,” “powdered cellulose,” etc. in the ingredients.
- Call or email the manufacturer to find out the plant source of their cellulose additive. Inquire about gluten testing.
- Check gluten-free food databases to see if the product or brand is listed as gluten-free.
- Look for gluten-free certification symbols from organizations like the GFCO, GFP, or GIG’s Gluten-Free Certification Organization (GFCO).
Following a gluten-free diet requires vigilance reading labels and asking questions to confirm products are safely gluten-free. While purified cellulose is likely fine, trace gluten exposures can add up.
Whole Grain Cellulose is Not Considered Gluten-Free
While purified cellulose additives are gluten-free, whole grain sources of cellulose are not considered gluten-free. Products like wheat bran, oat bran, and barley fiber contain both cellulose and gluten proteins.
Anyone following a gluten-free diet needs to avoid whole grains and brans from wheat, barley, rye, and contaminated oats. Fiber supplements derived from these gluten-containing whole grain sources are also unsafe.
Examples of grain-derived fibers that are not gluten-free include:
- Wheat bran
- Wheat fiber
- Barley fiber
- Rye fiber
- Oat bran (frequently cross-contaminated with gluten grains)
Checking labels and contacting manufacturers about fiber and cellulose sources in foods, supplements, and medications is important for gluten-free safety.
Safe Sources of Cellulose and Fiber for a Gluten-Free Diet
People following a gluten-free diet have to avoid all ingredients derived from wheat, barley, rye, and contaminated oats. But there are plenty of safe fiber options:
Purified cellulose additives: Cellulose gum, cellulose gel, microcrystalline cellulose, carboxymethyl cellulose, powdered cellulose made from non-gluten sources.
Fruits and vegetables: Fresh, frozen, canned produce provide fiber.
Beans, nuts and seeds: Contain insoluble and soluble fiber.
Gluten-free whole grains: Brown rice, quinoa, buckwheat, teff, millet, sorghum, corn contain cellulose and other fiber.
Certified gluten-free oats: A gluten-free source of soluble fiber. Choose certified oats to avoid cross-contamination with wheat.
Following a well-balanced gluten-free diet with whole foods naturally provides adequate cellulose and fiber intake for most people. Added cellulose can also be safe if verified as gluten-free.
The Bottom Line: Is Cellulose Gluten-Free?
The key points on whether cellulose contains gluten include:
- Cellulose is a carbohydrate fiber, while gluten is a protein. So cellulose does not inherently contain gluten.
- Gluten-containing grains like wheat, barley, and rye also naturally contain cellulose.
- During processing, cellulose can be purified and isolated from gluten grains. Highly-purified cellulose is considered gluten-free.
- Added cellulose has uses as an additive in processed foods, including adding fiber, improving texture, moisture retention, and more.
- Check labels for additives like cellulose gum, microcrystalline cellulose, carboxymethyl cellulose, etc. Contact manufacturers about sourcing and purity.
- Whole grain sources of cellulose like wheat bran contain gluten and are not considered gluten-free.
While purified cellulose additives are likely safe on a gluten-free diet, whole grain sources of cellulose contain gluten and should be avoided. Reading labels and verifying purity is important when purchasing foods with cellulose. Following a naturally fiber-rich gluten-free diet can help minimize reliance on added cellulose ingredients.
