Chewing gum has been a common habit for centuries, evolving from natural tree saps to the complex formulations available today. Questions often arise regarding its safety, particularly concerning a potential link to cancer. This article examines the scientific evidence surrounding chewing gum and its ingredients to address these concerns.
Understanding Chewing Gum Ingredients
Modern chewing gum typically consists of several key components that contribute to its unique texture and flavor. The primary element is the gum base, which provides the chewiness and elasticity. This base is a blend of polymers, resins, and waxes, often including synthetic materials like polyvinyl acetate and polyethylene, which are food-grade and designed for safe consumption. Sweeteners are added to provide flavor, ranging from natural sugars like cane sugar and corn syrup to artificial sweeteners such as aspartame, sucralose, and acesulfame-K, or sugar alcohols like xylitol and sorbitol.
Beyond the gum base and sweeteners, softeners like glycerin or vegetable oils help maintain a smooth and flexible texture. Flavorings, derived from natural oils or synthetic compounds, are crucial for taste. Additionally, some gums include artificial colors for visual appeal and preservatives like butylated hydroxytoluene (BHT) to extend shelf life. These ingredients are carefully formulated to create the desired chewing experience.
Scientific Evidence on Cancer Risk
Scientific bodies have extensively evaluated common components, including artificial sweeteners and preservatives. Aspartame, a widely used artificial sweetener, has been classified by the International Agency for Research on Cancer (IARC) as “possibly carcinogenic to humans” (Group 2B). This classification is based on limited evidence for cancer in humans, specifically for a type of liver cancer, and limited evidence from animal studies. However, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) concluded that the evidence of an association between aspartame consumption and cancer in humans is not convincing, reaffirming an acceptable daily intake.
Another artificial sweetener, sucralose, has shown no evidence of causing cancer in humans. While some laboratory studies have indicated that a sucralose byproduct, sucralose-6-acetate, may cause DNA damage and impact gut health, regulatory bodies generally consider sucralose safe. Preservatives such as BHT have shown possible carcinogenic effects in animal studies, but not in humans. Titanium dioxide, sometimes used for whitening, is also classified as a possible carcinogen by IARC, but primarily when inhaled in industrial settings, which is not relevant to its use in chewing gum.
Recent discussions have also included the potential for microplastics released from gum base to contribute to cancer risk. Chewing gum, with its polymer-based gum base, can release microplastic particles during chewing. While studies are ongoing, there is currently no conclusive human trial data directly linking ingested microplastics from gum to cancer development. Experts generally state there is no strong evidence directly linking chewing gum to cancer, with global health organizations considering common ingredients safe in normal amounts.
Other Health Considerations of Chewing Gum
Chewing gum can have various other effects on health. Chewing sugar-free gum, particularly those containing xylitol, can promote oral health by stimulating saliva production. Increased saliva helps neutralize acids, wash away food particles, and strengthen tooth enamel, thereby reducing the risk of cavities. Conversely, chewing gum with sugar can contribute to cavities because bacteria in the mouth feed on sugar and produce acids that erode enamel.
Some individuals may experience digestive discomfort from sugar alcohols like sorbitol, xylitol, and mannitol, commonly found in sugar-free gums. Consuming large quantities of these sugar alcohols can lead to symptoms such as bloating, gas, and diarrhea, particularly for those with irritable bowel syndrome (IBS). This is due to their incomplete absorption in the small intestine and subsequent fermentation by gut bacteria. Additionally, excessive or prolonged chewing can strain the temporomandibular joint (TMJ), which connects the jawbone to the skull. This repetitive motion can result in jaw pain, muscle fatigue, or exacerbate existing TMJ disorders.
Expert Consensus on Chewing Gum Safety
Major health organizations and scientific bodies generally consider chewing gum safe for most individuals when consumed in moderation. Regulatory agencies like the U.S. Food and Drug Administration (FDA) have evaluated the safety of various substances used in gum base and other ingredients. These evaluations ensure that approved ingredients, when used within established limits, do not pose significant health risks.
Despite ongoing research, the overall scientific consensus confirms that chewing gum does not have a direct, proven link to an increased risk of cancer in humans. Organizations like the World Health Organization (WHO) and JECFA continue to assess ingredients, reiterating their safety within acceptable daily intake levels. The current scientific understanding supports that regular, moderate chewing gum consumption is not associated with cancer development.