The phrase “overdose” usually conjures images of illicit drugs, but the reality is far broader. Among the 10 unexpected things you can overdose on are everyday items that seem harmless—or even beneficial—until they’re taken in excess. The line between a helpful dose and a harmful one can be razor‑thin, and the consequences range from nasty stomach aches to life‑threatening organ damage.
10 Unexpected Things to Keep in Mind
10 Soy Sauce
In 2013 a 19‑year‑old Virginian took a dare to gulp down 0.9 liters (about one quart) of soy sauce. The massive salt load sent his blood sodium soaring, triggering hypernatremia—a condition where excess salt pulls water out of cells, including brain cells, causing them to shrink and bleed. He suffered seizures, slipped into a coma, and was rushed to the hospital.
Doctors flushed his system with a mixture of water and dextrose, gradually lowering his sodium. After five hours his levels normalized, yet he stayed comatose for three days before waking on his own. Physicians called him lucky; he survived the extreme salt overdose without lasting neurological damage, marking the first recorded case of surviving such a high‑salt intake.
9 Tea
An Arkansas man developed kidney failure after drinking roughly sixteen 8‑ounce cups of iced tea daily. In May 2014 he presented with nausea, weakness, and body aches; doctors discovered his kidneys clogged and inflamed. The culprit was oxalate, a natural chemical in black tea (and foods like rhubarb and spinach) that, in excess, can damage kidneys.
The man’s oxalate consumption was three‑to‑ten times the average American’s. Harvard’s School of Public Health advises that up to four cups a day are safe, while sixteen cups far exceed the limit and can lead to irreversible kidney damage, often requiring lifelong dialysis.
8 Nutmeg
Nutmeg, a festive spice, can become toxic at roughly 4.4 grams (about two teaspoons). The spice contains myristicin, a compound that produces LSD‑like hallucinations when ingested in large amounts. Teens and prison inmates sometimes misuse nutmeg for its psychoactive effects, but the high dose brings severe gastrointestinal distress within an hour.
Hours later, users may experience heart‑related and nerve‑related problems, especially dangerous for those with undiagnosed cardiac issues. Hallucinations appear only after several hours, often prompting repeat dosing and worsening toxicity. Historically, nutmeg intoxication surged in the early 1900s, resurfaced in the 1960s, and continues to appear in modern case reports.
7 Toothpaste
In the early 1990s toothpaste labels warned: “Do Not Swallow. Use only a pea‑sized amount for children under six.” The FDA, deeming this insufficient, mandated a poison warning for fluoride‑containing toothpaste in 1997, arguing fluoride is a drug and poses toxicity risks.
Swallowing large quantities of fluoride‑free toothpaste generally causes only stomach upset, but ingesting fluoride‑laden paste can be fatal. Children are especially vulnerable; a single tube of children’s fluoride toothpaste holds enough fluoride to kill a child under 30 kg (66 lb). Even ingesting just 3 % of a tube can trigger acute fluoride poisoning, with flu‑like symptoms, dizziness, and gastric pain.
6 Cruciferous Vegetables
Cruciferous vegetables—broccoli, Brussels sprouts, kale—are praised for antioxidants, yet overconsumption can backfire. In 2011 a man with a mechanical heart, who was on anticoagulants, ate an excessive amount of Brussels sprouts at Christmas. These sprouts are rich in vitamin K, which promotes clotting and counteracted his medication, causing sudden heart complications.
Doctors identified the over‑dose of vitamin K as the cause and treated him successfully. Likewise, excess broccoli or kale can trigger hypothyroidism by interfering with thyroid hormone production. Nutritionists stress that reasonable portions are safe; only very high doses lead to the adverse effects, and those diagnosed with hypothyroidism are advised to limit cruciferous intake.
5 Star Fruit
Carambola, better known as star fruit, contains a toxin that can devastate the kidneys of anyone with pre‑existing renal weakness. Healthy kidneys can usually filter the toxin, but for compromised kidneys even a small amount can cause damage or failure.
The risk spikes for those unaware of early‑stage kidney disease, regular consumers, or people who drink star fruit juice on an empty stomach. Symptoms range from nausea, weakness, insomnia, seizures, to the hallmark hiccups in milder cases. Severe toxicity may require dialysis, yet kidney function may never fully recover.
4 Tuna
While tuna is a staple for many, it also accumulates mercury—a potent neurotoxin. Larger predatory fish, like tuna, ingest smaller fish and thus inherit their mercury load, which can build up to dangerous levels in humans.
Early signs of mercury poisoning include poor coordination, tingling in fingers and toes, tremors, and vision problems. Chronic exposure harms memory, learning, and can lead to kidney issues, respiratory failure, or death. The FDA advises that a 68 kg (150 lb) adult limit albacore tuna to one 170‑gram (6 oz) can every nine days; exceeding this—say, eating tuna every other day—can easily cause toxicity.
3 Muscle Cream
Muscle creams like Bengay or Icy Hot contain methyl salicylate, an anti‑inflammatory that penetrates the skin, reaches muscles, nerves, and eventually the bloodstream. Though intended for topical relief, excessive use can be fatal.
In 2007, 17‑year‑old track star Arielle Newman died after repeatedly applying high amounts of methyl salicylate‑laden creams and adhesive pads. The chemical accumulated in her system, reaching toxic levels. She also applied the cream before a track meet; the heat of running likely opened her pores, boosting absorption and contributing to her death.
2 Black Licorice
Black licorice, especially for those over 40, can wreak havoc on the heart. The FDA warned that consuming just 57 grams (about two ounces)—roughly three 1‑inch pieces—daily for two weeks can trigger serious cardiac issues.
The culprit, glycyrrhizin, lowers potassium levels, leading to abnormal heart rhythms, high blood pressure, and even congestive heart failure. Individuals with existing heart conditions face heightened risk. The FDA’s alert followed a 2016 case linking regular black licorice consumption to heart problems.
1 Vitamins
Vitamins are meant to boost health, yet over‑supplementation can spark cancers and other serious ailments. Water‑soluble vitamins (like vitamin C) are excreted via urine, but fat‑soluble vitamins (such as vitamin A) accumulate in body fat, reaching toxic levels that can damage the liver, cause birth defects, disrupt the central nervous system, and even trigger cancer.
In 1985, a trial administering high‑dose beta‑carotene (a vitamin A precursor) to smokers was halted when participants showed an 18 % higher lung‑cancer rate. A 2001 National Cancer Institute study found that men taking vitamin E were 17 % more likely to develop prostate cancer. Even vitamin C, though water‑soluble, can cause diarrhea, stomach cramps, and kidney stones when taken in excess.