Cellulose

Cellulose Definition and Structure

Cellulose is a a largely indigestible polysaccharide (a complex carbohydrate), composed of thousands of glucose molecules ^[1].

Function

In the human intestine, cellulose acts as an insoluble fiber, which can absorb water and thus increase the bulk of the stool. Cellulose cannot be digested, but can be partly broken down (fermented) by beneficial large intestinal bacteria into gases, and short-chain fatty acids, which can be absorbed ^[3]. Cellulose is not an essential nutrient, which means you do not need to consume it in order to be healthy.

Foods High in Cellulose

Cellulose is naturally present only in plant foods ^[2]:

• Cereals: whole grain wheat, barley, oats, cereal bran, bulgur, quinoa, cornmeal, brown rice
• Cabbage family of vegetables, for example, arugula, bok choy, Brussel’s sprouts, cabbage, cauliflower, collards, kale, kohlrabi, mustard greens, radishes, rutabaga, Swiss chard, turnips, turnip greens and watercress
• Fruits: avocado, berries, apples and pears with skins
• Legumes: peas, chickpeas, beans, lentils
• Nuts
• Potatoes with skins
• Seeds: pumpkin, sunflower and chia seeds with hulls

Modified Cellulose as a Food Additive, Pill Binder or Laxative

Cellulose extracted from wood pulp or cotton and chemically processed with acids or alkali can be added as a creaming agent or thickener to shredded cheese (parmesan), ice cream, fast food (burgers), powdered drink mixes and other commercial foods. Some types of modified cellulose are soluble and some insoluble ^[8]. Cellulose can be also produced from corn cobs or stalks, soybean hulls, sugar cane stalks, oat hulls, rice hulls, wheat straw, sugar beet pulp, bamboo, jute, flax and ramie.

Modified cellulose is also used as a filler in tablets and as a laxative.

Chart 1. Legend: *Bacterial cellulose is produced by bacteria. **Bacteria and cotton may be genetically modified organisms (GMO). Cellulose with E-numbers (E466, etc.) is approved in EU. GRAS = Generally Recognized As Safe by U.S. Food and Drug Administration (FDA).

Is cellulose good for you?

Constipation. In various studies, cellulose naturally present in foods did not significantly affect gut functions, but “cellulose” supplements (not further specified) increased the bulk of the stools and had a laxative effect ^[3,9,10,24].

Weight loss. In one study, cellulose supplements CM3 did not slow gastric emptying or increase the feeling of satiety in obese people ^[11].

Blood glucose and cholesterol. Cellulose naturally present in foods, which is insoluble fiber, does not likely lower blood lipid and glucose levels ^[3,8]. Supplements containing modified glucose, which is viscous soluble fiber, when consumed with meals, may reduce blood glucose spikes after meals; it may also reduce blood total and LDL cholesterol levels, when taken regularly for several weeks ^[8], but more research is warranted.

Cellulose Side Effects and Dangers

Cellulose from foods probably does not cause any significant side effects. Cellulose from supplements may cause mild abdominal bloating, excessive gas and loose stools ^[26]. In individuals with irritable bowel syndrome (IBS), foods high in cellulose and cellulose supplements may worsen symptoms ^[21]. Modified cellulose may trigger allergic reactions in sensitive individuals.

Cellulose-Nutrients Interactions

Modified, purified cellulose from supplements, in large doses (>10 g/day), but not likely cellulose from foods, may decrease absorption of calcium and iron ^[3].

Frequently Asked Questions

1. Why can humans digest starch but not cellulose?

Humans have intestinal enzymes that enable the digestion of starch, but do not have enzymes that digest cellulose. Normal intestinal bacteria can break down (ferment) some cellulose though.

2. Starch vs Cellulose

	STARCH	CELLULOSE
Made of	Glucose	Glucose
Digestible	Yes	No
Calories/g	4	<1
Sources	Cereals, potatoes	Cereal bran, fruits with peels, green vegetables, peas

3. Is cellulose a prebiotic?

According to Journal of Nutrition, cellulose is currently not considered a prebiotic ^[13].

4. Are cellulose supplements gluten-free?

Cellulose is mainly produced from wood pulp and cotton, so cellulose supplements should be gluten-free but check the product information leaflets.

5. Is cellulose vegan?

All types of cellulose, except bacterial cellulose are vegan.

Similar Nutrients

• Other insoluble dietary fiber: chitin and chitosan, hemicellulose, lignin
• Other polysaccharides: starch, glycogen