‘Vaccines cause autism,’ and other medical myths debunked

Whether it’s your grandmother telling you to slather butter on a burn or a neighborhood bully alleging that gum sits in the digestive tract for 7 years, there are probably a dozen baseless rumors for every sound piece of medical advice. While these common misconceptions are often amusing, they can pose some serious public health risks when they take on lives of their own.

These medical myths range from silly to dangerous, and they all share one thing in common: They’re about to be debunked.

Myth: Vaccines are linked to autism

This conspiracy theory is infuriating to doctors, educators, and public health advocates, and with good reason. Cases of chickenpox and measles, which the miracle of modern medicine had all but eradicated in the United States, are cropping up across the country thanks in part to militant anti-vaccine groups. Many members of these groups insist that vaccinations are linked to autism and other disorders. A November outbreak of chickenpox in Asheville, NC, has been attributed to the anti-vaccine movement, and the majority of the 220 individual cases of measles in 26 states and Washington, DC, occurred in people who weren’t vaccinated, according to the Centers for Disease Control and Prevention.

Fact: Vaccines have no relationship to autism spectrum disorder. Researchers of a 2014 study investigated the possible link between autism and vaccines amid the rising hysteria. The study included more than 1 million children analyzed across 5 cohort studies and more than 9,000 across 5 case-controlled studies. Not surprisingly, the study authors found no risk for children to develop autism as a result of administered vaccines. Meanwhile, the hundreds of needlessly suffering children show the steep consequences of not getting vaccinated.

Myth: Gum takes 7 years to digest

You probably first heard this one as a child after accidentally swallowing your bubblegum. No one quite knows who made up this myth, but it is definitely one for the ages.

Fact: Few studies have investigated the correlation between chewing gum and gastrointestinal functions. But gastroenterologists do know that most people empty their stomach contents—gum included—within 2 hours after eating. So, 7 years is out of the question, said gastroenterologist Nancy McGreal, MD, Duke Health, Durham, NC.

“In all the upper endoscopies I have done in both children and adults, I have yet to see a wad of gum lying around in the stomach,” Dr. McGreal said.

Myth: Hair and nails grow after death

Behold the exotic shrunken head, the ultimate in macabre memorabilia. Westerners first came across the Amazonian oddity in the mid-19th century while exploiting the resources of South America. According to Smithsonian magazine, in true colonizer fashion, European and North American traders quickly turned these leathery noggins into collectors’ items. Many swore that the length of their shrunken head’s hair grew over time.

Fact: Like many of the shrunken heads sold by Victorian swindlers, the assertion that hair grows after death is untrue. The same goes for finger- and toenails, according to an article in BMJ. After death, dehydration can cause the skin around hair follicles and nails to retract, causing the appearance of growth. The complex hormonal regulation that grows hair and nails doesn’t continue after a person dies.

Myth: Alcohol helps insomnia

Many night owls turn to chemical aids to fall asleep, with alcohol being one of the most common. Indeed, in a 1999 study, researchers found that insomniacs who drank small doses of alcohol experienced more restful sleep than usual.

Fact: While it’s true that consuming alcohol can cause drowsiness and initially helps drinkers fall asleep more quickly, it turns out that a nightcap actually does more harm than good. Researchers have shown that it can cause REM sleep disturbances, daytime drowsiness, and even sleep disorders if abused long term. To make matters worse, relying on alcohol as a nightly sleep aid also increases tolerance, leading to larger dose intake, increased sleep disturbances, and alcohol abuse. So, put the bourbon away and try some melatonin instead.

Myth: Knuckle cracking leads to arthritis

Your mother’s reprimands when you cracked your knuckles at the dinner table probably sounded a lot like this: “Enough! You’ll give yourself arthritis when you’re older.” But those empty threats probably started as an aversion to the sound rather than any real medical concern.

Fact: The effect of habitual knuckle cracking on hand function has been studied since the mid-20th century, but researchers have yet to find any link between the annoying habit and arthritis. In the long term, though, cracking the knuckles on a regular basis can cause hand swelling and reduced grip strength.