Chewing gum is a popular habit used for freshening breath, satisfying cravings, or relieving stress. While moderate chewing can stimulate saliva flow, the frequent, all-day habit introduces a range of unexpected physical consequences. This excessive and prolonged usage raises questions about the body’s ability to handle constant, non-essential mastication.
Stress on the Jaw and Facial Muscles
The human jaw is designed for the intermittent, powerful action of eating food, not for continuous, low-level movement throughout the day. Excessive gum chewing subjects the muscles of mastication, particularly the masseter and temporalis, to constant, repetitive strain. This overuse can lead to muscle fatigue and painful spasms that may radiate into the neck and head.
The temporomandibular joint (TMJ), which connects the lower jaw to the skull, is particularly vulnerable to this stress. Prolonged chewing can trigger or exacerbate a Temporomandibular Disorder (TMD). Symptoms of TMD include chronic pain, clicking or popping sounds in the joint, and difficulty opening or closing the mouth. Constant muscle tension created by chewing is also a factor in the development of tension headaches or the worsening of existing migraines.
Gastrointestinal Side Effects
Excessive gum chewing can lead to uncomfortable digestive consequences through two distinct physiological mechanisms. The first is aerophagia, or the involuntary swallowing of excess air. This occurs because the continuous chewing motion stimulates the oral cavity. This swallowed air accumulates in the stomach and intestines, leading to symptoms like bloating, abdominal discomfort, and increased burping.
The second mechanism relates to the ingredients in most sugar-free gums, which are sweetened with sugar alcohols, also known as polyols. These compounds, such as sorbitol, xylitol, and mannitol, are only slowly and incompletely absorbed by the small intestine. Once they reach the large intestine, gut bacteria ferment them, producing gas that contributes to flatulence and bloating.
Because polyols are poorly absorbed, they create an osmotic effect, drawing water into the bowel. This increase in fluid volume can result in a laxative effect, causing loose stools or diarrhea, especially when consumed in large quantities. Even relatively small amounts of sorbitol (5 to 20 grams) can cause gas and cramps, while higher doses may trigger osmotic diarrhea.
Impact on Dental Work and Enamel
Constant mechanical action from gum chewing presents a risk to dental structures, both natural and restorative. Over time, the repetitive grinding motion contributes to the wear and tear of tooth enamel, the hard, protective outer layer. This wearing down of enamel may lead to increased tooth sensitivity to hot or cold stimuli.
The sticky nature of gum, combined with the continuous pulling motion, also poses a threat to existing dental work. Constant chewing can loosen or completely dislodge restorations such as fillings, crowns, and bridges. This mechanical stress can necessitate costly and time-consuming repairs or replacements of dental appliances. People with orthodontic appliances, like braces or aligners, are often advised to avoid gum entirely.