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Carboxymethyl cellulose (CMC) is used as a thickening agent, it is a chemical compound created by reacting CELLULOSE or wood pulp, cotton lint with a derivative of acetic acid, it is also known as cellulose gum. It is powder in form and white in colour, when dissolved in water, it forms a clear solution or a gel. It is used as a thickener and an emulsifier in food and cosmetics. It is used in Ice cream, pies, beer, cake icing, jellies and also in diet food.
According to a 2015 study by the National Institute of Health, CMC affected gut bacteria and triggered inflammatory bowel disease symptoms and other changes in the gut, as well as obesity and a set of obesity-related disease risk factors known as metabolic syndrome. It was observed in mice that were predisposed to colitis, the emulsifiers triggered the disease. Emulsifiers like CMC, work like detergents and inhibit the mucous layer lining the gut. More research is needed to work out the long-term effects of CMC and other emulsifiers like it at levels that people consume.
CMC is not absorbed or digested, so the FDA allows it to be included with “dietary fiber” on food labels. CMC isn’t as healthful as fiber that comes from natural foods.
Short term studies of carcinogenity on dogs
Groups of two dogs were fed for a year 0.1, 0.3, 1.0 and 3.0 g/kg bw daily of CMC without effect on body and organ weights. One dog which was fed a higher dose of 50 g/kg bw daily for 30 days exhibited diarrhoea, slight weight loss and slight depression of red blood cell count without any histological changes (Hodge et al., 1950).
In another study, two dogs were fed doses of methylcellulose from 2 g to 100 g daily for one month without any noticeable effect (Bauer, 1945). Solutions containing 0.7 to 2.8% of methylcellulose of different molecular weights in 1% NaCl were administered by intravenous injection to 18 dogs in doses of 40 to 130 ml for five days a week with the maximum total dose of 5720 ml, injected within six months. Most of the animals died. Haematological reactions and the formation of foam cells were observed (Hueper, 1944).
Sources:
http://www.inchem.org/documents/jecfa/jecmono/v05je54.htm
https://cspinet.org/eating-healthy/chemical-cuisine#carboxymethylcellulose