15 Health Myths That Make Doctors Cringe

Updated: Jun. 16, 2021

Do you believe in "base tans"? Have you sworn off bread forever? Are you logging endless miles on the treadmill? These are just some of the surprising health myths that make doctors cringe.

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Don’t fall for these health myths

People sometimes unknowingly share bogus or outdated health information. We asked doctors to straighten things out and share the health myths that you need to stop believing.

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The more water you drink, the better

Water may be the healthiest beverage (not to mention necessary to life) but you can definitely get too much of a good thing, says Neal Schultz, MD, NYC dermatologist, founder of DermTv.com and creator of BeautyRx. At best, overhydrating will have you peeing every 30 minutes and at worst it can kill you. There is a “right way” to drink enough water and it comes down to trusting yourself. Your body is great at knowing how much water it needs, so forget drinking eight cups a day or half your body weight in ounces or any other prescribed amount. “You should drink to your thirst, not to meet an arbitrary number,” he advises.

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Getting a base tan can prevent sunburns

Even though skin cancer is the most common form of cancer in the U.S., many people still hold the faulty belief that getting a “base tan” will protect them from sunburns and cancer, make them look youthful, or clear up acne. Not so, says Jennifer Caudle, DO, board-certified family physician and assistant professor at Rowan University. There is no such thing as a “little” tan and all tanning increases your risk of cancer. Nor will it help your skin, in fact, sun damage is the primary cause of wrinkles, she adds.

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Gluten is bad for you

Gluten-free foods and diets are everywhere these days and many people believe that gluten, a protein found in some grains, is toxic to health or causes weight gain. Not true, says Caroline Apovian, MD, director of the Nutrition and Weight Management Center at the Boston Medical Center and professor at the Boston University School of Medicine. “Only about one percent of the U.S. population has Celiac disease and another small percentage may have a gluten intolerance, but if you do not have any of the above, eliminating gluten from your diet does not offer health benefits, including weight loss,” she says. Whole grains are a great source of fiber and vitamins and processed gluten-free versions of whole grain foods are often higher in sugar and preservatives, and lower in protein and fiber, making them the less healthy option, she adds. Check out these other carb myths that could be wrecking your health.

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Juice diets or other “detoxes” work

As long as you have a healthy liver and kidneys, your body can detoxify itself just fine, Apovian says. Moreover, trendy detox diets can harm you. “Drinking lots of juice does not assist with removing toxins from the body,” says Dr. Caudle. “In fact, many juices are high in sugar which can result in a blood sugar spike, quickly followed by a crash. Furthermore, being on a juice fast for an extended period of time may result in malnourishment.”

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You can only get an STD through having sex

“Sexually transmitted diseases” have “sex” right in the name so you might assume that is the only way to get them. Not so, Dr. Caudle says, adding that many people interpret that to mean only penetrative sex and think that a condom is all they need to protect themselves. While condoms are definitely necessary, the reality is that you can get some STDs through any type of sexual contact, including oral sex and even just skin-to-skin contact if one partner has open sores, she adds. Condoms are a great start but they’re not the only precaution you should be taking.

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You can exercise your way to a six-pack

Abs are made in the kitchen, not the gym. “At least once a day, I’m asked if there is an exercise I can prescribe that will give you ‘abs’ but what most people don’t understand is that everyone already has abs, they’re just likely hiding under layers of fat,” says Jasmine Marcus, DPT. Your best bet for beach-ready abs is to lose weight through a combination of diet and exercise—and then add a healthy dose of patience as this isn’t a quick fix, she adds. Want more weight loss advice? Check out 50 things your doctor wants you to know about losing weight.

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You can eat whatever you want as long as you’re skinny

Filling up with sugary treats or junk food will hurt you, even if you’re thin, says Robert D Willix Jr., MD, founder, and CEO of Enlightened Living Medicine. You can have your treats in moderation but overall you should be thinking about food in terms of “quality” not just “quantity.” Try these 37 diet secrets nutritionists won’t tell you for free.

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Breast cancer is the #1 killer of women

Breast cancer gets a lot of attention, but it’s not the primary cause of death for women in the U.S.—that’s still heart disease. Yet this false belief leads many women to have a fatalistic attitude about it, says Nicola Finley, MD, a physician at Canyon Ranch at Tucson. While you can’t completely prevent it, there is a lot you can do to reduce your risk of breast cancer, including talking to your doctor about your family history, eating a healthy diet, getting daily exercise, and maintaining a healthy weight, she says. While you’re at it, make sure you know these 15 breast cancer myths you can safely ignore.

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A hypoallergenic dog is a perfect pet for sensitive folks

“There is simply no such thing as a ‘hypoallergenic’ dog,” says Brian Modena, MD, Division of Allergy-Immunology at Scripps Health in La Jolla, California. This myth is based on the idea that it is the actual dog hair that causes allergies, so some dog breeds are designated as ‘hypoallergenic’ because they have low amounts of hair shedding. While these dogs may be easier on your carpets and black pants, they won’t be easier on your nose, because dog allergies are actually caused by microscopic proteins derived from the pet’s skin dander and saliva and carried through the air, he says. That said, you should probably weight the pros and cons of your dog sleeping in bed with you.

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Some things are just too gross to talk about with your doctor

You may be squeamish about discussing your stinky farts, genital discharge, or poop problems but that doesn’t mean your doctor is. In fact, failing to bring up “icky” symptoms with your doctor can make it harder to get the right diagnosis and treatment. “As a gastroenterologist, I have to frequently remind my patients that I talk about these ‘gross’ topics all day, every day—I am literally unshockable at this point,” says Roshini Raj, MD, associate professor of medicine at NYU Langone Medical Center, author of What the Yuck, the Freaky and Fabulous Truth About Your Body. “Bottom line: Your doctor needs to hear everything so talk to them.”

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Medical X-rays will give you cancer

Medically necessary X-rays, like those you get at the hospital or dentist’s office, will not give you cancer or harm you in any other way, says Gary Glassman, DDS., an endodontist. In fact, the chance of the doctor missing something important due to declining an x-ray is a much greater risk to your health than the tiny risk posed by the machines, he adds. “Standing outside in the sun for an hour exposes you to more radiation than you’d get from a full set of dental X-rays,” he explains. This is just one of 11 things your dentist wishes you knew.

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Wearing sunscreen will make you deficient in vitamin D

It’s true that your body makes vitamin D, a vital nutrient, when your skin is exposed to the sun. It’s also true that sunscreen blocks the sun’s rays. But these two facts don’t have to be mutually exclusive and they definitely don’t give you a pass for not wearing sunscreen, says Tsippora Shainhouse, MD, a board-certified dermatologist in Beverly Hills and clinical instructor at the University of Southern California. “Wearing sunscreen is still the best way to prevent deadly skin cancers and new studies have shown that wearing sunscreen does not cause vitamin D deficiency,” she explains. You can get easily get your recommended daily vitamin D dose through food, supplements, and small doses of sunshine. Find out the 10 sunscreen myths that make dermatologists cringe.

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You can diagnose yourself from the information you read on the Internet

This is one myth pretty much everyone knows on an intellectual level, yet we’re all likely guilty of going to “Dr. Google” for advice sometimes. “I hate hearing, ‘I read it on the Internet…’ Folks, Dr. Google is a really bad doctor!” says Josie L Tenore, MD, board-certified physician of My Fresh Skin. “While information from reputable sites may have validity, a lot of what’s out there is irrelevant, incomplete, or flat-out false.” You can use online info to start a conversation with your doctor but don’t use it to self-diagnose. And don’t pretend you didn’t get it off the Internet. Doctors can see right through these 17 common lies patients tell.

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The best time to make a baby is after the woman ovulates

Trying to have a little one? The majority of people believe that they should have sex the day the woman is ovulating or shortly thereafter to maximize their chances of conceiving, says Mary Jane Minkin, MD, an OB/GYN at Yale-New Haven Hospital and First Response spokesperson. In reality, the best time to have sex is just before ovulation, she explains. Also, forget about the special “baby-making” sex positions—any position works for conception, she adds.

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You have to do tons of cardio to lose weight

Cardiovascular exercise is great for your heart, lungs, and overall health but it’s not the magic bullet when it comes to weight loss and too much of it can even hinder your scale goals, Tenore says. “For all of you people out there spending 60 to 90 minutes on the treadmill every day, thinking you are burning fat, I’m sorry to say you are mistaken,” she says. “To lose weight and keep it off you need to build more muscle because the more muscle you have, the higher your basal metabolic rate.” Make sure that strength training is an integral part of your exercise routine. Read on for 10 more weight-loss myths you need to stop believing.