Is Cellulose Fiber Safe to Eat?

Cellulose is a fiber found in fruits, vegetables, and other plant foods as part of a plant’s cell walls. It’s found in tree bark and a plant’s leaves.

When you eat plant foods, you are consuming cellulose. But you may not be aware that cellulose fiber is also removed from plants to be used as an additive in many other foods as well as sold as supplements (1).

This article provides an overview of cellulose, where it’s commonly found, and whether or not it’s safe to consume.

What is cellulose?

Cellulose is made up of a series of sugar molecules linked together in a long chain. Since it is a fiber that makes up plant cell walls, it’s found in all plant foods.

When you eat food that contains it, cellulose stays intact as it passes through your small intestine. Humans do not have the enzymes needed to break down cellulose (1).

Cellulose is also an insoluble fiber and does not dissolve in water. When consumed, insoluble fibers can help push food through the digestive system and support regular bowel movements (2).

In addition to their role in healthy digestion, dietary fibers like cellulose may promote health in other ways. Studies suggest that high dietary fiber intake may reduce the risk of several diseases, including gastric cancer and heart disease (3).

Cellulose is an indigestible, insoluble fiber found in fruits, veggies, and other plants.

Safety of cellulose

Eating cellulose — especially from whole fruits and vegetables, grains, beans, and other plant foods — is generally considered safe.

Any potential downsides of cellulose are related to side effects from the overconsumption of fiber. If you eat too much cellulose or fiber in general or take cellulose supplements, you may experience:

• bloating
• stomach upset
gas
• constipation
• diarrhea

Current nutrition guidelines recommend that adults get at least 25 grams of fiber from foods per day but may need more or less depending on age, gender, and personal needs (6).

If you eat a fiber-rich diet or are increasing your fiber intake, be sure to drink plenty of water to prevent uncomfortable side effects. Exercise can also help.

Those who need to follow a low fiber diet should limit cellulose intake. Individuals who have a health condition that affects the digestive system, such as inflammatory bowel disease (IBD), also need to watch out for cellulose in foods.

Cellulose as a food additive is generally recognized as safe (GRAS) by the Food and Drug Administration (FDA). The levels of cellulose currently used in foods are not considered to be dangerous to humans (7).

Keep in mind, however, that getting fiber from whole plant foods is usually better than getting it from additives or supplements. These foods provide many other beneficial nutrients and compounds in addition to fiber.

Before adding cellulose supplements to your diet, it’s best to speak with a healthcare professional.

Consuming cellulose from foods, supplements, or additives is likely safe for most people. However, getting too much of it may lead to side effects that happen with the overconsumption of fiber, such as gas, bloating, and stomach pain.

The bottom line

Cellulose is a type of fiber that makes up the cell walls of plants. When you consume plant foods, you are eating cellulose.

Many other foods, ranging from shredded cheese to low calorie or diet foods, have added cellulose to help with different properties. Cellulose also exists in supplement form.

It’s generally safe to consume cellulose. But if you eat too much cellulose or fiber, you may have uncomfortable side effects like gas and bloating.