Every day, people make health decisions based on stories they’ve heard from friends, social media, or even well-meaning relatives. Health myths stick around not because they’re true, but because they’re simple, repeated often, and sometimes feel right. The truth? Most of them aren’t backed by science - and believing them can cost you time, money, or even your health.
Myth: You Lose 70-80% of Your Body Heat Through Your Head
This one’s been around for decades. It’s the reason parents make kids wear hats in winter, even if they’re bundled up everywhere else. The idea? That your head is some kind of heat escape hatch. But here’s the real science: your head makes up about 7-10% of your total body surface area. If you’re cold and only your head is exposed, yes - you’ll lose heat there. But so will your hands, your feet, or your neck if they’re uncovered. The myth came from a flawed 1950s U.S. military study where soldiers wore Arctic gear but left their heads bare. No part of your body is uniquely designed to dump heat faster than others. Heat loss is proportional to exposed skin. Wear a hat if it’s cold - but don’t ignore your hands or feet.
Myth: You Need to Drink Eight Glasses of Water a Day
That number - eight glasses - sounds clean, easy to remember. But where did it even come from? In 2002, Dr. Heinz Valtin from Dartmouth Medical School reviewed decades of research and found zero scientific proof supporting this rule. Your body gets water from food, coffee, tea, milk, even fruits and veggies. Hydration needs vary wildly based on your weight, activity level, climate, and health. A person working outdoors in Melbourne’s summer heat will need far more than someone sitting at a desk all day. The best signal? Thirst. If you’re not thirsty and your urine is pale yellow, you’re likely well-hydrated. Forcing down eight glasses a day won’t make you healthier - it might just make you run to the bathroom more often.
Myth: Chewing Gum Stays in Your Stomach for Seven Years
This one’s a classic parent scare tactic. “If you swallow gum, it’ll stick to your insides for years!” But that’s not how digestion works. Gum isn’t digested - it’s true. The base is synthetic rubber, and your body can’t break it down. But it doesn’t get stuck. It moves through your digestive tract like any other indigestible item - think corn kernels or seeds. It passes out in your stool within two to four days. Dr. Ian Tullberg, a family medicine specialist, confirmed this in a 2022 UCHealth interview. The only risk? Swallowing large amounts of gum in a short time - especially in young children - which can cause blockages. But one piece? No problem.
Myth: Sugar Makes Kids Hyperactive
It’s the birthday party classic. Kids eat cake, run around like maniacs - so sugar must be the cause. But over 23 double-blind, controlled studies have looked at this. The results? Sugar doesn’t cause hyperactivity. Not in kids. Not in adults. The 2021 JAMA Pediatrics meta-analysis found no link. So why does it seem real? Expectation bias. Parents who believe sugar causes hyperactivity are more likely to interpret normal kid energy as “sugar rush.” In one famous study, mothers were told their children had consumed sugar - even when they hadn’t - and reported more hyperactive behavior. The real culprit? Excitement, environment, and lack of routine. Sugar isn’t the villain here.
Myth: We Only Use 10% of Our Brain
This myth shows up in movies, ads, and self-help gurus promising “unlock your brain’s potential.” It’s false. Modern brain imaging - fMRI, PET scans - shows activity across the entire brain, even during simple tasks like talking or blinking. Different areas light up for different functions, but there’s no dormant 90%. The myth likely started from a misinterpretation of psychologist William James’ writings in the 1920s. Neuroscientists at the University of Alabama at Birmingham confirmed in 2022 that every part of the brain has a role. Even areas we don’t fully understand yet are active. You’re not wasting 90% of your mind - you’re using every bit of it, just not all at once.
Myth: Superfoods Like Acai or Goji Berries Are Miracle Cures
“Superfood” isn’t a scientific term. It’s a marketing label. Acai berries, kale, chia seeds, turmeric - they’re nutritious, sure. But they’re not magic bullets. The European Food Information Council reviewed hundreds of studies and found no evidence that any single food delivers extraordinary health benefits beyond what a balanced diet provides. Eating a variety of fruits, vegetables, whole grains, and lean proteins gives you more protection than chasing the latest “superfood” trend. A $100 jar of goji berries won’t reverse chronic disease. But eating a daily apple - or five different colored veggies - might. Focus on patterns, not potions.
Myth: Antibiotics Work on Colds and Flu
Antibiotics kill bacteria. Colds and flu are caused by viruses. Giving antibiotics for a viral infection doesn’t help - and it harms. Each unnecessary antibiotic course increases the risk of drug-resistant bacteria. The CDC estimates that at least 30% of antibiotic prescriptions in the U.S. are unnecessary. In Australia, public health campaigns have cut overprescribing by 25% since 2018 - but myths still persist. If you have a runny nose, sore throat, or cough, antibiotics won’t fix it. Rest, fluids, and time will. Save antibiotics for bacterial infections like strep throat or pneumonia - and only when a doctor confirms it.
Why Do These Myths Stick Around?
It’s not just ignorance. Myths survive because they fit into stories we already believe. Sugar = hyperactivity? That matches our experience with kids at parties. The head heat myth? It’s intuitive - your head is exposed, so it must be losing heat. The brain myth? It’s comforting to think we’ve got untapped potential. These ideas feel true, even when they’re not. Worse, corrections can backfire. If you tell someone “you’re wrong,” they dig in - especially if the myth is tied to their identity, culture, or trust in a source. That’s why the best debunking doesn’t just say “no.” It says “here’s what actually happens.”
How to Spot a Health Myth
- Does it sound too simple? Real science is rarely one-size-fits-all.
- Is it based on “everyone knows” or “my grandma said”? Anecdotes aren’t evidence.
- Does it promise a miracle fix? Real health changes take time and consistency.
- Is it promoted by someone selling something? “Buy this supplement to beat the myth!” is a red flag.
- Can you find peer-reviewed studies backing it? If not, be skeptical.
What Works Better Than Just Saying “That’s Not True”
Just telling people they’re wrong often makes them more attached to the myth. The best approach? The “truth sandwich.”
- Start with the truth. “Your body gets rid of chewing gum in a few days.”
- Briefly mention the myth - and label it clearly. “Some people think gum stays in your stomach for years, but that’s not true.”
- End with the truth again. “It passes through naturally, just like other food you can’t digest.”
This method, backed by the American Association for the Advancement of Science, improves retention by 47%. It avoids repeating the myth as if it’s true, and it reinforces the correct info. In healthcare settings, using this approach increases patient understanding and compliance with treatment plans.
What’s Changing in Health Communication
More hospitals and clinics are now training staff to tackle myths head-on. The WHO’s Myth Busters initiative has corrected over 2,300 health myths across 187 countries. Google’s “About This Result” feature now shows context on search results to flag misinformation. In Australia, 68 hospitals added myth-debunking guides to patient materials in 2023 - up from just 12 in 2020. The goal? Reduce confusion, prevent harm, and build trust. Patient education isn’t just about giving info - it’s about clearing out the noise.
Final Thought: Knowledge Is Power, But Only If It’s Accurate
Health myths aren’t harmless jokes. They lead people to skip vaccines, buy useless supplements, delay real treatment, or blame themselves for things they can’t control. The good news? You don’t need to be a scientist to spot a myth. Ask: “Where’s the proof?” “Who says so?” “Does this make sense?” And when you find a myth, share the truth - clearly, calmly, and kindly. You might just help someone make a better choice tomorrow.”
Is it true that you lose most of your body heat through your head?
No. This is a myth. Your head makes up about 7-10% of your total body surface area, so it loses roughly that percentage of heat when exposed - not 70-80%. Heat loss depends on how much skin is exposed, not which body part it is. If your hands or feet are cold and uncovered, they’ll lose heat just as quickly.
Do I really need to drink eight glasses of water every day?
No, there’s no scientific basis for the “eight glasses” rule. Your water needs depend on your body size, activity level, climate, and diet. You get water from food, coffee, tea, and other drinks. The best guide is thirst and urine color - if it’s pale yellow, you’re likely hydrated. Forcing extra water won’t improve your health.
Can swallowing chewing gum really cause it to stay in your stomach for years?
No. While your body can’t digest gum, it doesn’t stick around. It passes through your digestive system in two to four days, just like other indigestible items such as popcorn kernels or corn. The only risk is swallowing large amounts at once, especially in young children - which could cause blockages. One piece is harmless.
Does sugar make children hyperactive?
No. Over 23 controlled studies have found no link between sugar and hyperactivity in children. The perception often comes from context - birthday parties, excitement, lack of routine. Parents who expect sugar to cause hyperactivity are more likely to interpret normal behavior as such. Sugar doesn’t trigger hyperactivity, even in kids with ADHD.
Are superfoods like acai or goji berries really better than regular fruits and vegetables?
No. “Superfood” is a marketing term, not a scientific one. Acai and goji berries are nutritious, but they don’t offer unique health benefits you can’t get from everyday foods like apples, spinach, or blueberries. A balanced diet with variety provides more protection than any single “superfood.” Don’t pay extra for hype.
Can antibiotics cure a cold or the flu?
No. Antibiotics only work on bacterial infections. Colds and flu are caused by viruses, so antibiotics won’t help. Taking them unnecessarily increases the risk of antibiotic resistance, making future infections harder to treat. Rest, fluids, and time are the best treatments for viral illnesses.
Is it true that we only use 10% of our brain?
No. Modern brain scans show that nearly all parts of the brain are active at different times, even during simple tasks. The 10% myth likely came from a misunderstanding of early 20th-century psychology. There’s no hidden 90% waiting to be unlocked - your brain is fully engaged, just not all at once.
What to Do Next
If you’ve believed one of these myths, don’t feel bad. You’re not alone. Most of us have. The key is to stay curious. When you hear a health claim, pause. Ask where the info came from. Look for peer-reviewed studies or trusted health organizations like the WHO, CDC, or your local hospital. If you’re unsure, ask your doctor or pharmacist - they’re trained to separate fact from fiction. And when you learn something new, share it. One corrected myth can stop someone from making a harmful choice.