Did you know that when you travel in an airplane, your body gets pressurized, and the compression causes your organs to shrink? No? That’s because it’s not true.

Despite the claim’s utter bogusness, food blogger Vani Hari, a.k.a. FoodBabe, felt inspired to share it in a post about air travel (which she has since taken down, but don’t worry — the internet never forgets). It was accompanied by other baseless claims, such as, “The air you are breathing on an airplane is recycled from directly outside of your window,” (it’s not) and “The air that is pumped in isn’t pure oxygen either, it’s mixed with nitrogen, sometimes almost at 50%” (it’s unclear whether she thinks the air we breathe is normally “pure oxygen”).

The impure air “factoid” is followed by a statement designed to gain your trust, making you think she’s on your side and that the airlines are greedy capitalists, unconcerned with your health. She says, “To pump a greater amount of oxygen in costs money in terms of fuel and the airlines know this!”

Of course, she’s got just the information you need to protect yourself from nefarious airlines, GMOs, dangerous chemicals in your food, and so on, which she will share with you if you’ll just subscribe to her blog, and while you’re at it, buy a copy of her new book!

Hari claims her blog has over 3 million readers worldwide, so it would seem her scare tactics work well in driving readership. But her ignorant, unscientific and unfounded claims are more than a mere nuisance. They’re dangerous.

A friend of mine, a new mother, recently shared on Facebook a post from Hari’s site claiming that “glucola,” a drink given to pregnant women to test for gestational diabetes, contained toxic chemicals. The post was titled, “Shocking: Why Are Doctors Recommending This Toxic Drink?”

It didn’t take long for me to find blog posts by two separate obstetricians — you know, those people who are actually qualified to give medical advice to pregnant women — debunking Hari’s claim.

Hari is not a doctor, which she readily admits in a disclaimer on her website, followed by a renunciation of any responsibility should you choose to follow her advice. And that’s the problem with charlatans and pseudo-experts like Hari. She’s free to make whatever unsubstantiated, panic-inducing claims she likes, because she faces no consequences — unlike an actual doctor — if her bad advice causes harm.

Dihydrogen Monoxide: The Silent Killer

Attempting to highlight the need for critical thinking, an internet hoax starting in the 1990s warned of the dangers of “dihydrogen monoxide.” The claims on dhmo.org sound eerily similar to those on the Food Babe site:

Yes, you should be concerned about DHMO! Although the U.S. Government and the Centers for Disease Control (CDC) do not classify Dihydrogen Monoxide as a toxic or carcinogenic substance (as it does with better known chemicals such as hydrochloric acid and benzene), DHMO is a constituent of many known toxic substances, diseases and disease-causing agents, environmental hazards and can even be lethal to humans in quantities as small as a thimbleful.

While all of those things are technically true about “DHMO,” if you haven’t figured it out already, “dihydrogen monoxide” is just a different way of saying “H2O.” This hoax came to public attention, however, when a high school student convinced 43 out of his 50 classmates to sign a petition to ban the substance. The prank has been repeated throughout the years, always with the same result.

Learn to approach information with a healthy dose of skepticism, particularly on the internet. Don’t take anything at face value. Instead, stop and ask yourself, “Does this make sense?” Spend time learning about the source — are they an expert? What do they have to gain by sharing this information? What, if anything, do they stand to lose if they’re wrong? Look for opposing viewpoints, and give both sides careful consideration.

To remain gullible is easy. Skepticism and rational thought take work. They take time. But without skepticism and rational thought, all we’re left with is unfounded, harmful beliefs, driven into us through fear by people who can’t be bothered with the truth.