What are the side effects of carboxymethyl cellulose?

Carboxymethyl cellulose (CMC) is a commonly used food additive and pharmaceutical excipient, widely used in the food industry, pharmaceutical industry, cosmetics and other fields. It is mainly used as a thickener, stabilizer, emulsifier, etc. However, although carboxymethyl cellulose is considered a relatively safe substance, it may still cause side effects in some cases.

1. Digestive system problems

The main function of carboxymethyl cellulose in food is to increase viscosity and improve texture, but excessive intake may cause discomfort in the digestive system. Because it is a kind of dietary fiber, the human digestive system cannot completely digest it, causing some people to experience symptoms such as bloating, abdominal pain, diarrhea or constipation after consuming a large amount of food containing CMC. These symptoms mainly occur in people with sensitive digestive systems, especially those with irritable bowel syndrome or chronic gastroenteritis.

2. Allergic reactions

Although carboxymethyl cellulose itself is considered to be hypoallergenic, in some cases, some people may have allergic reactions to it. Allergic symptoms include rash, urticaria, itching, and in severe cases, even more serious allergic reactions such as difficulty breathing or laryngeal edema. Although this reaction is uncommon, people with a history of allergies should still be cautious.

3. Electrolyte imbalance

Due to its strong water absorption, CMC can absorb a large amount of water in the gastrointestinal tract, resulting in increased water content in the stool. For some people, especially children or the elderly, long-term or large-scale intake of carboxymethyl cellulose may cause water and electrolyte imbalance in the body, leading to dehydration, electrolyte disorders and other problems. This situation may be more obvious when the intake is too large. It is recommended to control the intake of CMC in the daily diet.

4. Effect on intestinal microorganisms

As a dietary fiber, carboxymethyl cellulose cannot be completely digested and absorbed by the human body, so it will reach the colon and be fermented by intestinal flora in the colon. This fermentation process may cause an increase in intestinal gas, causing discomfort such as bloating. At the same time, the presence of CMC may affect the normal balance of intestinal microorganisms, and long-term intake may inhibit the growth of beneficial bacteria, thereby affecting intestinal health.

5. Potential increase in intestinal permeability

Studies have shown that carboxymethylcellulose may increase intestinal permeability, leading to an increased risk of "leaky gut syndrome". In this case, the intestinal barrier function is impaired, and incompletely digested food particles, harmful bacteria or toxins may enter the blood through the intestinal wall, which in turn triggers an immune response and increases the risk of chronic inflammatory diseases.

6. Interaction with drugs

Carboxymethylcellulose is sometimes used in drugs as a disintegrant for tablets or as a sustained-release matrix for drugs. However, CMC may interact with certain drugs and affect the absorption or bioavailability of drugs. For example, it may affect the absorption of fat-soluble vitamins or certain drugs (such as digoxin). Therefore, when taking drugs containing CMC, attention should be paid to the dosage and method of taking the drug to avoid potential adverse reactions.

7. Effects on the kidneys

In some extreme cases, especially for patients with renal insufficiency, excessive intake of carboxymethylcellulose may have a negative impact on kidney function. CMC's metabolites may accumulate in the body, increase the burden on the kidneys, and lead to further deterioration of renal function. Therefore, patients with renal insufficiency should be extra careful when using products containing CMC.

8. Overall safety assessment

Although the above side effects may occur under certain conditions, carboxymethyl cellulose is generally considered safe. Both the International Food Additive Codex (Codex Alimentarius) and the U.S. Food and Drug Administration (FDA) have listed CMC as a substance generally recognized as safe (GRAS). As long as it is used within the prescribed limits, the negative impact of CMC on health is relatively small. However, it should still be used with caution for individuals with specific sensitive groups or special health conditions.

As a widely used food additive and drug excipient, carboxymethyl cellulose is generally safe, but in some cases it may cause side effects such as digestive system discomfort, allergic reactions, electrolyte imbalance, intestinal health problems and interactions with drugs. Especially for sensitive people, patients with chronic diseases or those who consume large amounts for a long time, special attention should be paid to the amount and frequency of use. If you experience discomfort, you should seek medical attention in time and stop using the relevant products.