"Breakfast is the most important meal — it boosts metabolism and helps you lose weight."

🔴 Myth (as a weight-loss hack)

Pooling the randomized trials, people told to eat breakfast actually took in ~260 more calories a day and weighed slightly more, not less. Eat it if you like it — just don't expect it to burn fat.

📋 Systematic review + meta-analysis · 13 RCTs — Sievert et al., BMJ 2019 · read the study → · permalink →

"Sugar makes kids hyperactive."

🔴 Myth

Across 23 blinded studies — where no one knew who got sugar vs. a sweetener — sugar had no effect on kids' behavior or attention. It's the party, not the cake.

📋 Meta-analysis · 23 studies — Wolraich et al., JAMA 1995 · read the study → · permalink →

"MSG gives you headaches."

🔴 Myth

When MSG is properly hidden in food and blinded, the "MSG headache" mostly vanishes. The scare traces back to weak, unblinded studies — and MSG occurs naturally in tomatoes and parmesan.

📋 Systematic review of human studies — Obayashi & Nagamura, J Headache Pain 2016 · read the study → · permalink →

"Vitamin C prevents colds."

🔴 Myth (for most of us)

In 29 trials of 11,000+ people, taking vitamin C daily did not lower your odds of catching a cold (it trims a little off how long one lasts). The exception: people under extreme physical stress, like marathon runners.

📋 Cochrane meta-analysis · 29 trials, 11,306 people — Hemilä & Chalker, 2013 · read the study → · permalink →

"A daily multivitamin keeps you healthy."

🔴 Myth (mostly)

In 84 studies of 740,000 people, vitamin/mineral supplements did little or nothing to prevent heart disease, cancer, or early death in well-nourished adults — and beta-carotene raised lung-cancer risk in smokers. Real food still wins.

📋 Systematic review for the USPSTF · 84 studies, 739,803 people — O'Connor et al., JAMA 2022 · read the study → · permalink →

"Antioxidant supplements help you live longer."

🔴 Myth

Across 67 trials of 230,000+ people, antioxidant pills didn't extend life — and beta-carotene, vitamin A and vitamin E were linked to slightly higher mortality. Get your antioxidants from food, not a bottle.

📋 Cochrane meta-analysis · 67 RCTs, 232,550 people — Bjelakovic et al., 2008 · read the study → · permalink →

"Fish-oil (omega-3) supplements protect your heart."

🔴 Myth (for supplements)

The largest review — 86 trials, 160,000+ people — found omega-3 supplements have little or no effect on heart attacks, strokes, or dying. (They do lower triglycerides, and eating actual fish is a different question.)

📋 Cochrane meta-analysis · 86 RCTs, 162,796 people — Abdelhamid et al., 2020 · read the study → · permalink →

"Calcium and vitamin D pills prevent broken bones."

🔴 Myth (for most older adults)

Across 33 trials of 51,000 older adults living at home, calcium and/or vitamin D supplements did not lower the risk of hip or other fractures. (It's a different story if you're truly deficient or in a care facility.)

📋 Systematic review + meta-analysis · 33 RCTs, 51,145 people — Zhao et al., JAMA 2017 · read the study → · permalink →

"Glucosamine and chondroitin fix joint pain."

🔴 Myth

Pooling the trials, glucosamine/chondroitin didn't beat placebo for joint pain or slow the arthritis — and the independent, non-industry studies showed the smallest effects of all.

📋 Network meta-analysis · 10 trials, 3,803 patients — Wandel et al., BMJ 2010 · read the study → · permalink →

"Blue-light glasses protect your eyes and help you sleep."

🔴 Myth

In the biggest review — 17 randomized trials — blue-light-filtering lenses didn't ease the eye strain they're sold to fix, and no solid trial has shown they help you sleep or protect your retina (the sleep results were mixed, and almost none of the studies even tested the retina). Your screen habits matter; the amber tint doesn't.

📋 Cochrane systematic review · 17 RCTs — Singh et al., 2023 · read the study → · permalink →

"Eating eggs is bad for your heart."

🔴 Myth (for most people)

Pooling three large studies of 215,000+ people — plus an updated meta-analysis — up to one egg a day was not linked to higher heart-disease risk in the general population. (People with diabetes are the possible exception.)

📋 Pooled cohorts + meta-analysis · 215,000+ people — Drouin-Chartier et al., BMJ 2020 · read the study → · permalink →

"Ginkgo biloba sharpens your memory."

🔴 Myth

Across 36 trials, ginkgo showed no consistent, meaningful benefit for memory or thinking — the results were inconsistent and unreliable. A supplement-aisle staple the evidence just doesn't back.

📋 Cochrane meta-analysis · 36 trials — Birks & Grimley Evans, 2009 · read the study → · permalink →

"Echinacea keeps you from catching a cold."

🔴 Myth

Across 24 trials, echinacea products didn't reliably prevent colds — any benefit was small at best and inconsistent across studies. Save it for the tea you actually like.

📋 Cochrane meta-analysis · 24 trials — Karsch-Völk et al., 2014 · read the study → · permalink →

"Magnesium stops muscle cramps."

🔴 Myth (for most people)

In the pooled trials, magnesium was no better than placebo at reducing the cramps most adults get — including the classic nighttime leg cramp. (Pregnancy cramps are a separate, still-uncertain question.)

📋 Cochrane meta-analysis · 11 RCTs — Garrison et al., 2020 · read the study → · permalink →

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