An unwrapped stick of chewing gum
|Main ingredient(s)||Chicle or polyisobutylene|
Chewing gum is a type of gum made for chewing, and dates back at least 5,000 years. Modern chewing gum was originally made of chicle, a natural latex. By the 1960s, chicle was replaced by butadiene-based synthetic rubber which is cheaper to manufacture. Most chewing gums are considered polymers.
Chewing gum in various forms has existed since at least 5,000 years ago during the Neolithic period. 5,000-year-old chewing gum with tooth imprints, made of bark tar, has been found in Kierikki, Yli-Ii, Finland. The bark tar of which the gums were made is believed to have antiseptic properties and other medicinal advantages. The ancient Aztecs used chicle as a base for making a gum-like substance. Women in particular used this type of gum as a mouth freshener.
Forms of chewing gums were also used in Ancient Greece. The Greeks chewed mastic gum, made from the resin of the mastic tree. Many other cultures have chewed gum-like substances made from plants, grasses, and resins. The American Indians chewed resin made from the sap of spruce trees. The New England settlers picked up this practice, and in 1848, John B. Curtis developed and sold the first commercial chewing gum called The State of Maine Pure Spruce Gum. Around 1850 a gum made from paraffin wax was developed and soon exceeded the spruce gum in popularity. William Semple filed an early patent on chewing gum, patent number 98,304, on December 28, 1869.
Modern chewing gum was first developed in the 1860s when chicle was imported from Mexico for use as a rubber substitute. Chicle did not succeed as a replacement for rubber, but as a gum it was soon adopted and due to newly established companies such as Adams New York Chewing Gum (1871), Black Jack (1884) and “Chiclets” (1899), it soon dominated the market. Synthetic gums were first introduced to the U.S. after chicle no longer satisfied the needs of making good chewing gum. The hydrocarbon polymers approved to be in chewing gum are styrene-butadiene rubber, isobutylene, isoprene copolymer, paraffin wax, and petroleum wax.
One of the best known chewing gum manufacturers worldwide is Wrigley. Wrigley was founded by William Wrigley, Jr. in 1892 in Chicago. It was known as Wrigley’s Spearmint Gum in 1906 and within four years was the bestselling gum in the U.S. and is still the largest market for gum in the world. According to Wrigley surveys, the average American chews 300 sticks per year. Historically, during and after World War II, the image of an American soldier chewing a piece of Wrigley's gum became an icon in the American media. Wrigley began donating their gum to the troops, and it was regarded as a stress reliever and a healthier alternative to smoking.
Effects on health 
Dental health 
Sugar-free gum sweetened with xylitol has been shown to reduce cavities and plaque. The sweetener sorbitol has the same benefit, but is only about one-third as effective as xylitol. Xylitol is specific in its inhibition of Streptococcus mutans, bacteria that are significant contributors to tooth decay. Xylitol inhibits Streptococcus mutans in the presence of other sugars, with the exception of fructose. Daily doses of xylitol below 3.44 grams are ineffective and doses above 10.32 grams show no additional benefit.
Food and sucrose have a demineralizing effect upon enamel that has been reduced by adding calcium lactate to food. Calcium lactate added to toothpaste has reduced calculus formation. One study has shown that calcium lactate enhances enamel remineralization when added to xylitol-containing gum, but another study showed no additional remineralization benefit from calcium lactate or other calcium compounds in chewing-gum.
Other studies indicated that the caries preventive effect of chewing sugar-free gum is related to the chewing process itself rather than being an effect of gum sweeteners or additives, such as polyols and carbamide.
A helpful way to cure halitosis (bad breath)is to chew gum (breath mints also help this cause). Chewing gum not only helps to add freshness to breath but can aid in removing food particles and bacteria associated with bad breath from teeth. It does this by stimulating saliva, which essentially washes out the mouth. Chewing gum can also help with the lack of saliva or xerostomia since it naturally stimulates saliva production.
A 2010 study looked at the effects of chewing gum after meals following an orthodontic procedure, to see if chewing exercises caused subjects pain or discomfort, or helped maintain a large occlusal contact area. 35 adult volunteers chewed gum for 10 to 15 minutes before or after three meals each day for 4 weeks. 90% of those questioned said that the gum felt "quite hard", and half reported no discomfort.
Use in surgery 
Several randomized controlled studies have investigated the use of chewing gum in reducing the duration of post-operative ileus following abdominal and specifically gastrointestinal surgery. These suggest gum chewing, as a form of 'sham feeding'[clarification needed], is a useful treatment therapy.
Chewing gum after a colon surgery helps the patient recover sooner. If the patient chewed gum for fifteen minutes for at least four times per day it will speed up their recovery by a day and a half faster. The average patient took .66 fewer days to pass gas and 1.10 fewer days to have a bowel movement. Saliva flow and production is stimulated when gum is chewed. Gum also gets the juices flowing and is consider "sham feeding". Sham feeding is the role of the central nervous system in the regulation of gastric secretion.
Chewing gum is used as a novel approach for the treatment of gastroesophageal reflux disease (GERD). One hypothesis is that chewing gum stimulates the production of more bicarbonate-containing saliva and increases the rate of swallowing. After the saliva is swallowed, it neutralizes acid in the esophagus. In effect, chewing gum exaggerates one of the normal processes that neutralize acid in the esophagus. However, chewing gum is sometimes considered to contribute to the development of stomach ulcers. It stimulates the stomach to secrete acid and the pancreas to produce digestive enzymes that aren't required. In some cases, when consuming large quantities of gum containing sorbitol, gas and/or diarrhea may occur.
Possible carcinogens 
Concern has arisen about the possible carcinogenicity of the vinyl acetate (acetic acid ethenyl ester) used by some manufacturers in their gum bases. Currently the ingredient can be hidden in the catch-all term "gum base". The Canadian government at one point classified the ingredient as a "potentially high hazard substance." However, on January 31, 2009, the Government of Canada's final assessment concluded that exposure to vinyl acetate is not considered to be harmful to human health. This decision under the Canadian Environmental Protection Act (CEPA) was based on new information received during the public comment period, as well as more recent information from the risk assessment conducted by the European Union.
Swallowed gum 
One old wives' tale says that swallowed gum will remain in a human's stomach for up to 7 years, as it is not digestible. According to several medical opinions, there seems to be little truth behind the tale. In most cases, swallowed gum will pass through the system as quickly as any other food.
There have been cases where swallowing gum has resulted in complications requiring medical attention. A 1998 paper describes a four-year-old boy being referred with a two-year history of constipation. The boy was found to have "always swallowed his gum after chewing five to seven pieces each day", being given the gum as a reward for good behavior, and the build-up resulted in a solid mass which could not leave the body. A 1½-year-old girl required medical attention when she swallowed her gum and four coins, which got stuck together in her esophagus. A bezoar is formed in the stomach when food or other foreign objects stick to gum and build up, causing intestinal blockage. As long as the mass of gum is small enough to pass out of the stomach, it will likely pass out of the body easily, but it is recommended that gum should not be swallowed or given to young children who cannot understand this point.
Many schools do not allow chewing gum because students often dispose of it inappropriately, the chewing may be distracting in class, and the gum might carry diseases or bacteria from other students.
The Singapore government outlawed chewing gum in 1992 because it was becoming a danger when wedged in the sliding doors of underground trains. However, in 2002 the government allowed sugarless gum to be sold in pharmacies if a doctor or dentist prescribed it.
Disney, Universal Studios, Seaworld, Amsterdam Schiphol Airport, and Busch Gardens Theme Parks have banned the selling of gum to help keep the grounds cleaner.
Effects on the environment 
Chewing gum is commonly stuck underneath benches and tables or to the surface of sidewalks, and is difficult to remove once dried. Gum bonds strongly to asphalt and rubber shoe soles because they are all made from polymeric hydrocarbons. In 2000, a study on Oxford Street, one of London’s busiest shopping streets, showed that a quarter of a million blobs of chewing gum were stuck to its pavement.
See also 
- "Student dig unearths ancient gum" BBC.co.uk.
- "The History of Chewing Gum and Bubble Gum" page of About.com Inventors.
- "History Of Chewing Gum" page of BeemarsGum.org.
- Patent number 98,304
- Chewing gum companies in 1860-1900
- Deshpande A, Jadad AR (2008). [-~~~~ = http://jada.ada.org/cgi/content/full/139/12/1602 "The impact of polyol-containing chewing gums on dental caries: a systematic review of an original randomized controlled trials and observational studies"]. Journal of the American Dental Association 139 (12): 1602–1614. PMID 19047666.
- Milgrom P, Ly KA, Roberts MC, Rothen M, Mueller G, Yamaguchi DK (2006). "Mutans streptococci dose response to xylitol chewing gum". Journal of Dental Research 85 (2): 177–181. doi:10.1177/154405910608500212. PMC 2225984. PMID 16434738.
- Kakuta H, Iwami Y, Mayanagi H, Takahashi N (2003). "Xylitol inhibition of acid production and growth of mutans Streptococci in the presence of various dietary sugars under strictly anaerobic conditions". Caries Research 37 (6): 404–409. doi:10.1159/000073391. PMID 14571117.
- Kashket S, Yaskell T (1997). "Effectiveness of calcium lactate added to food in reducing intraoral demineralization of enamel". Caries Research 31 (6): 429–433. doi:10.1159/000262434. PMID 9353582.
- Schaeken MJ, van der Hoeven JS (1993). "Control of calculus formation by a dentifrice containing calcium lactate". Caries Research 27 (4): 277–279. doi:10.1159/000261550. PMID 8402801.
- Suda R, Suzuki T, Takiguchi R, Egawa K, Sano T, Hasegawa K (2006). "The effect of adding calcium lactate to xylitol chewing gum on remineralization of enamel lesions". Caries Research 40 (1): 43–46. doi:10.1159/000088905. PMID 16352880.
- Schirrmeister JF, Seger RK, Altenburger MJ, Lussi A, Hellwig E (2007). "Effects of various forms of calcium added to chewing gum on initial enamel carious lesions in situ". Caries Research 41 (2): 108–114. doi:10.1159/000098043. PMID 17284911.
- Caries preventive effect of sugar-substituted chewing gum- 3-year community intervention trial to determine the caries preventive effect of sugar-substituted chewing gum among Lithuanian school children, and to assess compliance with the instructions for gum use.
- Emsley, J. (2004). Vanity, vitality, and virility. (pp. 189-197). New York: Oxford University Press Inc.
- (2010). Chewing gum exercises. Dental Abstracts, 55(4), 214.
- Fitzgerald JE, Ahmed I (December 2009). "Systematic review and meta-analysis of chewing-gum therapy in the reduction of postoperative paralytic ileus following gastrointestinal surgery". World J Surg 33 (12): 2557–66. doi:10.1007/s00268-009-0104-5. PMID 19763686.
- "Chewing Gum Associated With Enhanced Bowel Recovery After Colon Surgery". Science Daily.
- Gastroesophageal Reflux Disease (GERD)
- "Risky chewing gum, gum, gum". Janethull.com. Retrieved 2012-01-25.
- "Substance found in chewing gum could be labelled toxic". Canada.com. 2008-05-30. Retrieved 2012-01-25.
- "Summary of Public Comments Received on the Government of Canada's Draft Screening Assessment Report and Risk Management Scope on Bisphenol A" (PDF). Retrieved 2012-01-25.
- Matson, John. "Fact or Fiction?: Chewing Gum Takes Seven Years to Digest: Scientific American". Sciam.com. Retrieved 2012-01-25.
- Milov, David E. (August 1998). "Chewing Gum Bezoars of the Gastrointestinal Tract". Pediatrics 102 (2): 22.
- Babich, Jay P (2004). "Chewing Gum Bezoar". Gastrointestinal Endoscopy. p. 871.
- "B-schools ban chewing gum on campus". indiatimes.com. 26 June 2009. Retrieved 2 August 2010.