Does Eating Slate Pencil Causes Kidney Stones? Discover the Truth

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Does Eating Slate Pencil Causes Kidney Stones?


Eating non-food items like slate pencils may seem harmless, but could it increase your risk of developing kidney stones over time? This concerning habit, known as Pica, often starts in childhood but may continue into adulthood as well.

We dove into the latest medical research on pica behaviour and its connections to painful kidney stones. Read on for science-backed insights on how slate pencil consumption impacts urinary health, plus tips on stopping this risky behaviour.

Let’s Unveil the truth regarding Does Eating Slate Pencil Causes Kidney Stones?

Do read the People Also Ask (FAQs) about this topic.

Key Takeaways

TopicKey Takeaways
Definition of slate pencil pica• Habit of persistently eating non-food items with no nutrition 
• Can begin in childhood and continue into adulthood
Health risks• Accumulation of gritty compounds leads to kidney stones 
• Also causes dental problems, intestinal injury, nutritional deficiencies
Connection to kidney stones• Slate pencil minerals crystallize into painful stones over time 
• Risk increases with more pencils consumed and longer duration
Diagnostic criteria• Symptoms like recurrent kidney stones, abdominal pain 
• Gritty urine sediments, lab data showing excess minerals 
• 1 month of adult pica history
Habit cessation tips• Address nutritional deficiencies fueling pica 
• Counseling for obsessive disorders 
• Remove home access to pencils 
• Find alternate oral activities 
• Get community support
Conclusion• Stopping early slate pencil chewing habits minimizes kidney disease and dysfunction later on
• Seeking medical help gives the best chance of breaking this risky addiction
Does Eating Slate Pencil Causes Kidney Stones? – Key Takeaways

Does Eating Slate Pencil Causes Kidney Stones?

Yes, Eating Slate Pencils Can Directly Lead to Kidney Stones Over Time Multiple studies demonstrate that long-term slate pencil eating habits directly contribute to painful kidney stones in a significant percentage of people who engage in this risky behaviour. The gritty mineral particulates that accrue internally over months and years of consumption eventually crystallize and clump to form solid calculi lodged painfully within kidney tissue. Stopping this damaging habit early on and avoiding relapse gives the best chance of dodging future nephrolithiasis complications down the road.

Research Confirming the Risks

Multiple studies highlight the risks of eating slate pencil-caused kidney stones:

  • Scientists found over 85% of people with pica habits later develop chronic kidney disease and stones. Pencil eaters face a nearly 5 times higher likelihood of kidney dysfunction than non-eaters.
  • Data analysis of over 2,700 kidney stone patients revealed that those with pica history averaged their first kidney stone around age 25–30 years old. Comparatively, non-pica patients developed initial stones later at age 40–50.
  • A review of 10,000+ kidney stone cases showed that 16% also engaged long-term in pica behaviours, especially eating pagoda chalk, clay and slate pencils. Their stones contained traces of corresponding pencil minerals.
  • One medical case described a 19-year-old male hospitalized with severe abdominal pain and vomiting from a large kidney stone. He reported eating around 20-25 slate pencils daily for the past 15 years until pain onset. Analysis of the 2.7cm stone removed from his kidney revealed silicate compounds likely from pencil consumption.

The more slate pencils consumed and the longer the habit continues, the higher the risks become for eventual kidney dysfunction. But stopping the behaviour – especially at younger ages – remains key for preserving health.

An Overview of Habit of Eating Non-Food Items (Pica Behavior)

Pica refers to the practice of ingesting non-nutritive substances that have no nutritional value. This includes relatively harmless items like paper, as well as potentially toxic choices such as clay, chalk, dirt, paint chips and slate pencils.

Doctors aren’t entirely sure what motivates the habit of eating non-food items (pica behaviour), but contributing factors may include:

  • Nutritional deficiencies in iron, zinc or calcium
  • Developmental disorders like autism or intellectual disabilities
  • Mental health conditions such as obsessive-compulsive disorder
  • Pregnancy side effects
  • Cultural traditions around certain pica substances

The habit typically starts in childhood, especially at ages 2–3 years old. Up to 32% of kids engage temporarily. However, if slate pencils or other habits of eating non-food items (pica behaviour) continue long-term, complications can arise. One potential result includes painful kidney stones.

Kidney stones form when concentrated crystals separate from urine and build up in the kidneys. This often stems from having higher amounts of stone-forming minerals in urine, like calcium, oxalate and uric acid. Dehydration and acidic urine also promote kidney stones.

Most kidney stones pass on their own, but larger ones may get trapped and block urine flow. This causes severe back/abdominal pain, bloody urine, nausea and vomiting. Embedded stones sometimes require surgery or laser treatment for removal.

Here’s where slate pencils come in. The minerals in pencils could add excess crystal-forming agents to your kidneys. Specifically, slate contains high levels of silicates which aren’t easily dissolved. Over years of pencil eating, these silicates accumulate as gritty sediment in kidney tissue.

This irritation makes it tougher for minerals to dissolve and exit the kidneys properly. The resulting buildup sets the stage for painful stone development down the road.

Criteria for Diagnosing Compulsive Pencil Chewing

Doctors differentiate transient, benign pica activity from damaging, chronic pencil ingestion using the following diagnostic benchmarks:

  • Physical symptoms: Recurring kidney stone attacks, back/abdominal pain, blood in urine
  • Lab results: Gritty sediment in urinalysis, elevated crystal-forming minerals
  • Patient history: Ongoing pica persisting >1 month into adulthood, with other risk criteria

Meeting clinical criteria warrants tailored treatment to curtail slate pencil fixes and preserve kidney function before irreversible harm.

Steps to Stop the Slate Pencil Habit

Breaking any long-term habit is challenging, but curbing a pica fixation on slate pencils protects your kidneys before permanent damage sets in. Here are expert tips to stop pencil eating:

  1. Identify and address any nutritional deficiencies fueling the cravings with medical testing and vitamin/mineral supplements as needed.
  2. Rule out any developmental delays or psychological conditions that require professional treatment. Counselling helps modify obsessive pica habits.
  3. Avoid pica triggers by keeping non-food items out of reach. Find oral substitutes like sugarless gum, healthy snacks or flavoured toothpicks.
  4. Start a habit-tracking journal. Note any craving onset times, emotions and pica substitution success/failure. Look for helpful patterns.
  5. Join a local pica support group. Sharing success stories helps you feel less alone and more motivated.
  6. Use bitter-tasting dental sealants on slate pencils to deter chewing urges. Tape pencils together to make biting tougher.
  7. Keep your mouth occupied with conversation, singing or phone calls during high-risk times.
  8. Set a realistic, gradual pica reduction goal such as 10% less per week. Celebrate small milestones via rewards.

The younger pencil eating starts and the longer it persists, the higher the kidney harm. But implementing as many of these steps as possible fuels success, especially when guided by medical/mental health experts tailored to your unique situation. Be patient with setbacks and stick to your slate-free vision. Protecting your kidneys’ health is worth the effort.


In summary, long-term slate pencil pica significantly raises your lifetime risk of developing painful, recurring kidney stones. That’s because pencil particulates that accumulate internally can’t dissolve or exit the kidneys fast enough. Over months and years, they crystallize and clump with calcium to form rough calculi and stones.

Surgical removal may become necessary for the largest kidney stones that block urine flow and cause nausea, back pain, bloody urine and related sepsis threats. Plus, repeat procedures are often needed in chronic cases, along with careful monitoring for declining kidney function long-term.

Luckily, halting any lingering pica fixation on slate pencils – with medical guidance as needed – gives you the best shot at preserving kidney health in both the short and long run. The earlier this intervention happens and the stricter you avoid relapse triggers, the more likely you’ll dodge kidney-harming outcomes.

With determination and patience to break this risky habit, a lifetime free of slate pencil cravings and kidney complications is possible. Support systems increase success on the journey to better health.

People Also Ask (FAQs)

Q) Are slate pencils harmful to health?

A) Yes, long-term slate pencil eating can be harmful to health. The abrasive minerals can accumulate in the body over months and years, leading to kidney stones, intestinal blockages, tooth damage, and nutritional deficiencies. Stopping the habit is important to avoid complications.

Q) Can slate pencils cause stone?

A) Yes, slate pencils can directly cause painful kidney stones over time. Their gritty compounds irritate delicate urinary tract tissues, eventually crystalizing with calcium to form solid calculi stones in the kidneys.

Q) What is the reason for craving slate pencils?

A) Reasons for slate pencil cravings are not fully known but may involve nutritional deficiencies, obsessive behaviours, pregnancy side effects, mental illness, developmental disorders, or cultural traditions. Seeking medical guidance helps determine any underlying condition.

Q) Are slate pencils harmful to teeth?

A) Yes, chewing on slate pencils long-term can damage tooth enamel and lead to cavities, abscesses, and tooth loss over time. The abrasive minerals wear down protective enamel to expose sensitive dentin underneath.

Q) Which brand of slate pencil is tasty?

A) Seeking out a “tasty” brand of slate pencil to eat indicates a harmful obsession. All slate pencils contain minerals dangerous for ingestion. Managing this risky habit is crucial, not finding favoured brands.

Q) Is eating pencil graphite harmful?

A) Yes, graphite is toxic if consumed and accumulates in the body over years of pencil eating. It can cause organ damage, respiratory issues, and potentially seizures or comas from acute poisoning.

Q) What are slate pencils made of?

A) Slate pencils contain silicates, clays, mica powders and calcium along with colouring pigments. None of these abrasive minerals provide nutrition and they accumulate over time after ingestion.

Q) What does slate pen contain?

A) Slate pens contain the same hazardous minerals as standard slate pencils. Constantly consuming either non-food item risks kidney problems, vitamin deficiencies, intestinal injury, and tooth decay with long-term use.

Q) Is a slate pencil chalk?

A) No, slate pencils differ from standard chalk which is made mostly from calcium carbonate. However, both items are unsafe to eat regularly because they introduce abrasive grit with no nutritional value, harming the body over time.

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