Eating paper is not a healthy habit, though risks depend heavily on the type and quantity consumed. A small, accidental piece of clean paper is generally harmless and will pass through the digestive system. However, ingesting larger amounts or chemically treated paper presents two distinct dangers: chemical toxicity and physical obstruction. While the core material is biologically inert, additives used for printing, coloring, and finishing are the primary source of chemical concern; the bulk fiber poses a mechanical threat.
What is Paper Made Of?
Paper is fundamentally composed of cellulose, a durable plant fiber derived primarily from wood pulp. Cellulose is a long chain of glucose units that humans cannot break down because we lack the necessary digestive enzyme, cellulase. Since it cannot be digested or absorbed, the material passes through the gastrointestinal tract largely intact, similar to dietary fiber. Therefore, paper itself is not chemically poisonous and holds no nutritional value.
The pulping process uses various chemicals, such as chlorine compounds for bleaching, to achieve the bright white appearance of most papers. Although these chemicals are used in manufacturing, the finished product contains only trace amounts of residual chemicals. Small amounts of clean, untreated paper will simply be excreted without causing a toxic reaction due to the indigestible nature of the cellulose. However, the safety profile changes significantly once non-fiber components are introduced.
The Risks of Inks, Dyes, and Coatings
The greatest toxic concern comes not from the cellulose but from the chemicals added to the paper. Modern printing inks, especially black ink used in newspapers and office printers, are often soy or vegetable oil-based, making them benign in small quantities. However, older inks or brightly colored dyes can contain heavy metals like lead, cadmium, or nickel, which pose a poisoning risk if consumed repeatedly or in large doses.
Many specialized paper products contain concerning chemical coatings. Thermal paper, commonly used for store receipts, is coated with leuco dyes and color developers, often including Bisphenol A (BPA) or its substitute, Bisphenol S (BPS). Both BPA and BPS are known endocrine disruptors that can interfere with the body’s natural hormones. These chemicals are readily absorbed through the skin or digestive tract. Glossy magazines, wax paper, and heavily processed packaging may also contain plasticizers, phthalates, or other chemical finishes not intended for ingestion.
Paper’s Physical Effects on the Digestive System
Beyond chemical risks, paper presents a physical hazard due to its indigestible, fibrous nature. The most immediate danger is choking, particularly if a dry, large piece is swallowed without proper chewing or hydration. Once past the throat, the cellulose acts as dense, non-dissolving bulk within the stomach and intestines.
Consuming a large quantity of paper, particularly high-density types like cardboard or tissue, can lead to the formation of a bezoar, a compacted mass of undigested material. A paper bezoar, sometimes called a xylobezoar, can cause a serious gastrointestinal obstruction. This blockage is a particular risk for individuals with pre-existing digestive conditions or for those, such as children, who consume paper repeatedly over time.
When to Seek Medical Guidance
Prompt medical evaluation is necessary if paper ingestion is followed by specific, concerning symptoms. Signs of a possible gastrointestinal obstruction include severe, cramping abdominal pain, persistent vomiting, abdominal swelling, or the inability to pass gas or have a bowel movement. These symptoms indicate a medical emergency where the intestinal contents are blocked.
Medical attention is also advised if a known hazardous type of paper was consumed, even in a small amount. This includes thermal receipt paper or paper with noticeable amounts of brightly colored or metallic ink, due to the higher risk of chemical exposure. If the ingestion is not a one-time accident but a recurrent behavior, a doctor should be consulted to rule out underlying conditions like pica, which involves the persistent craving and eating of non-food substances.