History of Chewing Gum

Gum has its roots in 14th century French, Latin, Greek, and Egyptian languages, roughly meaning “resin from dried sap of plants” [1]. The earliest use of the word in American English dates to about 1842. The first evidence of someone chewing gum, however, is much older. In 2007, archaeologists found a 5,000-year-old piece of well-chewed birch bark in western Finland [2]. It was common for people living in the Neolithic period to chew birch bark to treat infections although they didn’t understand why it worked (it contains phenol compounds which have antiseptic properties). Throughout recorded history, gum in some form was chewed by people in many cultures including the Ancient Greeks, Native Americans, and early American settlers [3].

In 1848, a man named John B. Curtis developed the first chewing gum made for sale to the public [3]. It was called “State of Maine Spruce Gum” and was made with, as you would guess, the sap of spruce trees. By the 1850s, tree sap was replaced by paraffin wax in the more popular gums of the day [4]. Interestingly, there was no food technology at the time for sweetening the gum, so chewers had to dip the gum repeatedly into powdered sugar and pop it back into their mouths to keep the sweetness flowing. Sweetening innovations eventually came followed shortly by flavorings (well, beyond what a spruce tree tastes like). Today, gum technology has become very sophisticated with the sweetener and flavorings being incorporated into a matrix to give extended release capabilities beyond the three minutes of chewing time for gum made in the 1980s [5].

Figure: Early 1900s advertisement for gum products made by Thomas Adams [10].

Early chewing gum came in small pieces and the flavor did not last long. Modern-day gum in larger sticks came into being in the 1870s thanks to Thomas Adams, an American scientist and inventor [6]. Adams combined the gum from a tropical evergreen tree known as chicle with sugar and flavorings and heated it. He found the properties of the gum were far superior to the paraffin-based gums of the time. Adams coupled this invention with the patent he received for a gum manufacturing machine to create “Blackjack,” the first commercially available flavored chewing gum. In addition, if you’ve heard of a chewing gum called Chiclets, it was introduced into the market by Adams in 1899 and the name comes from the chicle ingredient.

Along with the popularity of chewing gum (the average American chews about 1.5 pounds (300 sticks) of gum per year [6]) comes the problem of driving gum trees into extinction over time. Modern chemistry came to the rescue of the gum trees after World War II when synthetic gum bases were developed [6]. Some gum ingredients are a mystery because companies want to protect their formulation secrets and because gum doesn’t have strict labeling requirements for ingredients. If you look at a package, most of the time it will only list “gum base.” However, we know that synthetic gum bases contain a variety of components including elastomers, resins, and waxes, synthetic polymers including polyvinyl acetate, polyethylene, styrene-butadiene rubber, and even natural latex.

How is Chewing Gum is Made

Making chewing gum is a fairly simple process, not like you’re led to believe from watching Willy Wonka and the Chocolate Factory. You can even make your own at home [7].

To begin the large-scale manufacturing of sticks of chewing gum, chicle, rubber, latex – whatever the gum base recipe calls for, is mixed together and ground to a coarse consistency and then dried at a warm temperature for 1-2 days [8]. In the next step, the base is heated in a kettle until it melts into a thick syrup. The syrup is purified by centrifuging and passing it through screens to remove any unmelted particles or contaminants. Then, the rest of the ingredients like sugar, corn syrup, flavorings, colorings, and softeners are added. The ingredients are mixed thoroughly until smooth, rolled out, and cooled.

After cooling, the gum gets kneaded for several hours until it is smooth and rubbery. Smaller pieces are extruded, cut off, and rolled out to about 0.17 inches thick and dusted with powdered sugar. A machine scores the dusted sheets of gum into small rectangles and they are set aside to season at a constant temperature and humidity [8], [9]. After the desired amount of time, the sheets are broken into individual sticks of gum along the score lines, wrapped in foil, and packaged.

Now, if you’re wondering about gumballs (and who didn’t love gumball machines as a kid), the process is different after the ingredients have been mixed together and kneaded [8]. Machines form the gum into a long cylinder, cut it into individual pieces, seal the ends, and shape each one into a sphere. The gumballs are stored for several hours so the outside surface dries and then they’re coated with a solution containing sugar and coloring. After drying under hot hair, the gumballs are rolled in beeswax to get their shiny finish.

Throw it in Your Sister’s Hair, Peel it Off Your Shoe

Chewing gum has more uses than just a delivery system for delicious flavors or making you look cool in your audition for Grease. Of course, chewing gum containing nicotine is a popular and effective method for quitting smoking [10]–[13]. But, chewing gum also benefits the body and mind in ways you may not imagine.

In 2012, the European Union (EU) approved several generic health claims for sugar-free gum related to the prevention of dental cavities [14] and the American Dental Association also recognizes the benefits of chewing gum in dental health [15]. The benefits include reducing plaque acids in the mouth and promoting the remineralization of tooth enamel.

Studies conducted since the early 2000s have confirmed that gum chewing has positive effects on several aspects of brain function including memory, attention, alertness, and cognitive processing speed [16]–[21]. In addition, medical research has found that chewing gum has positive effects for treating gastroesophageal reflux disease (GERD) [22], [23] and in reducing intestinal obstructions after abdominal surgery [24]–[26]. Chew on that. 😊

Figure: photograph of an old gumball machine [11].

References

[1] “Origin and meaning of gum,” Online Etymology Dictionary. [Online]. Available: https://www.etymonline.com/word/gum. [Accessed: 08-Aug-2018].

[2] “Student dig unearths ancient gum,” BBC News, 20-Aug-2007. [Online]. Available: http://news.bbc.co.uk/2/hi/uk_news/6954562.stm. [Accessed: 08-Aug-2018].

[3] “The story of gum,” International Chewing Gum Association. [Online]. Available: http://www.gumassociation.org/index.cfm/facts-figures/the-story-of-gum/. [Accessed: 08-Aug-2018].

[4] “Chewing gum,” Wikipedia. 21-Jul-2018.

[5] C. Bucholz, “Flavoring Chewing Gum,” Chemical & Engineering News, vol. 85, no. 40, p. Letters, 2007.

[6] R. Burks, “What’s That Stuff? Chewing Gum,” Chemical & Engineering News, 2007. [Online]. Available: https://pubs.acs.org/cen/whatstuff/85/8532sci2.html. [Accessed: 08-Aug-2018].

[7] “How to Make Chewing Gum,” Instructables. [Online]. Available: http://www.instructables.com/id/How-to-Make-Chewing-Gum/. [Accessed: 11-Aug-2018].

[8] “How chewing gum is made - manufacture, making, history, used, procedure, industry, machine, Raw Materials,” How Products are Made. [Online]. Available: http://www.madehow.com/Volume-1/Chewing-Gum.html. [Accessed: 11-Aug-2018].

[9] “Manufacturing Process,” International Chewing Gum Association. [Online]. Available: http://www.gumassociation.org/index.cfm/science-technology/manufacturing-process/. [Accessed: 11-Aug-2018].

[10] M. J. JARVIS, M. RAW, M. A. H. RUSSELL, and C. FEYERABEND, “Randomised controlled trial of nicotine chewing-gum,” British Medical Journal, vol. 285, p. 4, 1982.

[11] J. L. Tang, M. Law, and N. Wald, “How effective is nicotine replacement therapy in helping people to stop smoking?,” BMJ, vol. 308, no. 6920, pp. 21–26, Jan. 1994.

[12] K.-O. Fagerström, “Effects of nicotine chewing gum and follow-up appointments in physician-based smoking cessation,” Preventive Medicine, vol. 13, no. 5, pp. 517–527, Sep. 1984.

[13] T. Lancaster, L. Stead, C. Silagy, and A. Sowden, “Effectiveness of interventions to help people stop smoking: findings from the Cochrane Library,” BMJ, vol. 321, no. 7257, pp. 355–358, Aug. 2000.

[14] “REACH - Chemicals - Environment - European Commission.” [Online]. Available: http://ec.europa.eu/environment/chemicals/reach/reach_en.htm. [Accessed: 30-Apr-2018].

[15] “Oral Health Topics - Chewing Gum,” American Dental Association, 2016. [Online]. Available: https://www.ada.org/en/member-center/oral-health-topics/chewing-gum. [Accessed: 12-Aug-2018].

[16] S. V. Onyper, T. L. Carr, J. S. Farrar, and B. R. Floyd, “Cognitive advantages of chewing gum. Now you see them, now you don’t,” Appetite, vol. 57, no. 2, pp. 321–328, Oct. 2011.

[17] R. Stephens and R. J. Tunney, “Role of glucose in chewing gum-related facilitation of cognitive function,” Appetite, vol. 43, no. 2, pp. 211–213, Oct. 2004.

[18] A. Smith, “Effects of chewing gum on mood, learning, memory and performance of an intelligence test,” Nutritional Neuroscience, vol. 12, no. 2, pp. 81–88, Apr. 2009.

[19] A. P. Allen and A. P. Smith, “Effects of chewing gum and time-on-task on alertness and attention,” Nutritional Neuroscience, vol. 15, no. 4, pp. 176–185, Jul. 2012.

[20] Y. Hirano et al., “Effects of chewing on cognitive processing speed,” Brain and Cognition, vol. 81, no. 3, pp. 376–381, Apr. 2013.

[21] Y.-H. Choi et al., “The brain activation pattern of the medial temporal lobe during chewing gum: a functional MRI study,” Neural Regen Res, vol. 12, no. 5, pp. 812–814, May 2017.

[22] B. R. Smoak and J. A. Koufman, “Effects of Gum Chewing on Pharyngeal and Esophageal pH,” Ann Otol Rhinol Laryngol, vol. 110, no. 12, pp. 1117–1119, Dec. 2001.

[23] R. Moazzez, D. Bartlett, and A. Anggiansah, “The Effect of Chewing Sugar-free Gum on Gastro-esophageal Reflux,” J Dent Res, vol. 84, no. 11, pp. 1062–1065, Nov. 2005.

[24] S. Li, Y. Liu, Q. Peng, L. Xie, J. Wang, and X. Qin, “Chewing gum reduces postoperative ileus following abdominal surgery: A meta-analysis of 17 randomized controlled trials,” Journal of Gastroenterology and Hepatology, vol. 28, no. 7, pp. 1122–1132, Jul. 2013.

[25] M. K. Y. Chan and W. L. Law, “Use of Chewing Gum in Reducing Postoperative Ileus After Elective Colorectal Resection: A Systematic Review,” Dis Colon Rectum, vol. 50, no. 12, pp. 2149–2157, Dec. 2007.

[26] J. E. F. Fitzgerald and I. Ahmed, “Systematic Review and Meta-Analysis of Chewing-Gum Therapy in the Reduction of Postoperative Paralytic Ileus Following Gastrointestinal Surgery,” World J Surg, vol. 33, no. 12, pp. 2557–2566, Dec. 2009.

[27] “Adams Chewing Gum -1920A,” Magazine Art. [Online]. Available: http://www.magazineart.org/main.php/v/ads/foodandbev/candyandtreats/AdamsChewingGum-1920A.jpg.html. [Accessed: 12-Aug-2018].

[28] “Chewing Gum, Old, Childhood Memory,” Pixabay. [Online]. Available: /en/chewing-gum-old-childhood-memory-2721336/. [Accessed: 12-Aug-2018].