The culprit: sorbitolDoctors say that chewing sugar-free gum after a meal decreases mouth's bacterial acidity, the main factor involved in tooth decay, due to the abundant salivation, diluting and neutralizing the acid. And here comes the shock: a new research published in the "British Medical Journal" shows that exaggerating with the chew gum could cause stomach conditions and non-healthy weight loss.
This was linked to the sweetener used - sorbitol (E420) - also found in many sugar-free sweets and cereals. Sorbitol has 60 % of the sugar's calories, but 14 or more chewing gum sticks daily could severely affect your health. This chemical is poorly absorbed by the gut and has laxative properties.
The German doctors signal the case of two patients experiencing chronic diarrhea and severe weight loss. This challenges researches made by the Wrigley company, signaling a positive weight loss induced by chewing gum, by decreasing the urge to munch all the time. Also, a gum stick has 5 to 10 calories and the chewing gum consumes around 11 calories an hour.
The team at the Charite Universitatsmediz, in Berlin medical school, discovered that the 21-year-old woman, one of the two patients, chewed large quantities of sugar-free gum, meaning about 18-20 g sorbitol daily (one stick of chewing gum has around 1.25g of sorbitol) and had lost 24lb (11kg), weighing 6st 6lb (40.8kg). The 46-year-old man, i.e. the second patient, chewed 20 sticks of sugar-free gum and consumed 200g of sweets daily, ingesting 30g of sorbitol each day. In 2007, he had lost 48.5lb (22kg). When both patients ceased consuming sorbitol-containing foods, their diarrhea was gone, and they started gaining weight.
"People should be warned of the dangers of too much sorbitol, including diabetics who rely on low-sugar or sugar-free foods. Both our patients consumed large amounts of sorbitol, which belongs to the family of polyalcohol sugars, like mannitol and xylitol, some of which are regularly used as laxatives. However, sorbitol is also used as a sweetener in many sugar-free foods and drug products", wrote the authors.
"Our cases show that sorbitol consumption can cause not only chronic diarrhea and functional bowel problems but also considerable unintended weight loss (about 20% of usual body weight). Thus, the investigation of unexplained weight loss should include detailed dietary history with regard to foods containing sorbitol", they added.
"Excessive consumption of polyols, such as sorbitol, can have a laxative effect in some individuals. Studies generally indicate that people can consume up to 40g of sorbitol without experiencing a laxative effect, subject to the individual and other components of his or her diet - a level not even approached by normal consumption of sugar-free chewing gum. To reach the threshold of excessive consumption of sorbitol through use of gum alone, someone would have to chew close to 100 pellets of gum daily", said a spokesperson for the Wrigley Company.