Don't Be Misled! These Daily "Common Sense" Myths Are Actually Wrong

In daily life, we often hear bits of common sense, such as applying toothpaste to burns for pain relief, using baking soda to remove rust, or fumigating vinegar to prevent colds... Yet some knowledge is correct, while some is false. Therefore, we need to distinguish between right and wrong daily tips. Let's debunk these commonly misbelieved "common sense" myths.

01 Can Brown Sugar Water Relieve Menstrual Cramps?

For women, monthly periods can be difficult. The claim that drinking brown sugar water relieves menstrual cramps has persisted for long, but many report, "It didn’t work for me."

In reality, hot drinks dilate blood vessels. For some women, warm brown sugar water may ease pain, but not because sugar has special properties—it’s the heat, similar to drinking hot water or applying a warm compress. Additionally, excessive sweets can exacerbate mood swings and anxiety. For severe cramps, seek medical help promptly.

02 Should You Apply Toothpaste to Burns for Cooling Pain Relief?

Applying toothpaste to burns is wrong. While mint in toothpaste provides temporary cooling, it promotes bacterial growth and infection. Other "folk remedies" like soy sauce, sesame oil, Sichuan pepper powder, or Vaseline not only hinder healing but also increase infection risks.

For burns, immediately rinse the affected area with cool water to reduce heat damage and infection risk. For burns under clothing, cool with cold water, then gently remove clothes or cut them open lengthwise. Cover the wound with a clean gauze to keep it clean and dry. If blisters form, do not pierce them—small blisters will absorb naturally, while large or severe blisters require medical attention.

Experts advise: For small, superficial burns, perform first aid at home and then see a doctor. For severe burns, seek immediate medical care.

03 Can Baking Soda Remove Rust and Water Scale?

Baking soda (sodium bicarbonate) is an acid salt that dissolves in water to form a weak alkaline solution. It appears as white crystalline powder with a slightly salty, alkaline taste. Since water scale consists of calcium carbonate, magnesium carbonate, and magnesium hydroxide—none of which react with bases—only acids can remove it. Thus, baking soda cannot eliminate water scale.

The claim that "baking soda + white vinegar removes rust" is also unscientific. Rust (iron oxide) doesn’t react with bases, so baking soda can’t remove rust. While acetic acid can slowly dissolve rust, white vinegar contains only 3%–5% acetic acid, making it ineffective for rust removal.

04 Can Cacti Protect Against Radiation?

Some believe cacti, resistant to strong sunlight and UV rays, can shield against radiation—hence many office workers place cacti on their desks.

This is mostly a psychological effect. Plants absorb red light, far-red light (infrared), violet light, and UV rays for photosynthesis. However, solar radiation energy differs from the electromagnetic radiation emitted by electronic devices. There’s no evidence that cacti shield or absorb such radiation better than other objects. Studies show electromagnetic fields around ordinary computers are far below safety limits, so radiation protection is unnecessary.

05 Can Wok Cooking Supplement Iron?

The rumor that "cooking with a cast-iron wok supplements iron" has long prevailed. In reality, iron released from woks during cooking is non-heme iron, with an absorption rate of less than 3%. The body needs heme iron for efficient absorption, so even long-term wok use can’t effectively prevent anemia. No studies, domestic or foreign, show that iron from woks solves national anemia problems.

Thus, don’t rely on woks for iron, and don’t worry that non-stick or stainless-steel pans are worse for iron supplementation.

06 Can Tilting Your Head Back, Pinching Your Nose, or Stuffing Paper Stop Nosebleeds?

As children, we were taught to tilt our heads back and pinch our noses to stop nosebleeds. But are these methods correct?

The nose connects to the nasal cavity, sinuses, and nasopharynx, with a passage to the mouth. Tilting the head back only redirects blood flow—it may seem like the bleeding stops, but blood actually flows backward into the mouth or stomach. Pinching the nose is correct: squeeze both nasal wings to apply pressure if the bleeding point is near the anterior nostril.

To stop a nosebleed:

1. Lean forward to prevent swallowing blood.
2. Pinch the nasal wings with your thumb and index finger for 5–10 minutes.
3. Apply a cold compress to the forehead and face.
   If these steps fail, seek medical help immediately.

07 Can Swallowing Rice or Drinking Vinegar Solve a Fishbone Stuck in the Throat?

Folk remedies suggest swallowing rice, drinking vinegar, or eating whole greens/bread to push down a stuck fishbone.

In reality, the safest approach is to seek medical help promptly. A fishbone stuck in the esophagus can damage nearby organs (heart, lungs, bronchus, aorta), causing esophageal perforation, mediastinal infection, lung infection, or even fatal aortic hemorrhage. Drinking vinegar is ineffective—soaking a fishbone in vinegar for 30+ minutes is needed to soften it. Swallowing rice or bread pushes the bone deeper, increasing removal difficulty and risking infection or ulcers.

08 Is Ginger Soup at Night as Harmful as Arsenic?

The saying goes, "Ginger soup in the morning is like ginseng soup; ginger soup at night is like arsenic." Is this true?

Studies show ginger contains nutrients like volatile oils, gingerol, and starch. It improves blood circulation, stimulates gastric juice secretion for digestion, and has antibacterial effects. Gingerol scavenges free radicals, while shogaol and zingerone suppress vomiting. However, consuming ginger at night—due to compounds like gingerol—may irritate intestinal peristalsis and disrupt sleep. While nighttime ginger isn’t as toxic as arsenic, it harms health, so experts advise against heavy nighttime consumption.

09 Can Fumigating Vinegar Prevent Colds?

Many fumigate vinegar at home during cold seasons to disinfect and prevent colds, sharing this folk remedy in WeChat groups.

Vinegar, a weak acid, has some disinfectant properties, but its oxidizing ability is too weak. Diluted in the air, it can’t kill cold viruses. Excessive vinegar fumes can cause breathing difficulties, nausea, and damage to skin and respiratory mucosa. Thus, fumigating vinegar doesn’t prevent colds.