There’s a curious thing about misinformation: the more an untruth gets repeated, the more factual it seems. That’s certainly the case with myths about health and wellness, which are often passed down through generations of trustworthy and well-intentioned people. Here, experts across the University of Kansas Medical Center take seven of the most common health and medical myths, some of which you might have heard your whole life, and explain why they just aren’t so.

MYTH 1: EVERYONE’S MEMORY FAILS AS THEY AGE.

The brain changes with age, but to say that memory always fails as part of the aging process is false, according to Ryan Townley, M.D., assistant professor of neurology at the KU School of Medicine and a primary investigator at the KU Alzheimer’s Disease Center.

It is true that the brain, including its short-term memory structures, begins to shrink around the age of 40. But while the average scores on word-recall tests may decline with age, Townley sees patients well into their 80s maintaining their cognitive capacities and scoring within the expected ranges on cognitive tests.

So what about those lapses in memory many of us notice as we advance in years, such as walking into a room and forgetting why we went there or not being able to remember the name of someone we should know? Townley said this is a normal aspect of aging and can indicate a full brain rather than a failing one.

“I had a wise professor suggest that, as we get older, we build up a larger library, and it takes us longer to find the ‘book’ [name] we’re looking for,” Townley said.

Moreover, there are steps you can take to maintain brain function as you age. Studies at the KU Alzheimer’s Disease Center suggest that the brains of people who get regular aerobic exercise shrink more slowly than those who don’t. And biology isn’t everything: Some people’s minds retain the ability to function despite damaged or dying brain cells.

“Lifestyle factors can play a large role in maintaining this cognitive reserve,” said Townley. “Diet, physical exercise, proper sleep, cognitive and social engagement ― including challenging your brain with novel tasks ― are all important for proper brain health and function in aging.”

MYTH 2: YOU SHOULD WALK 10,000 STEPS A DAY TO STAY FIT

“While it can be incredibly satisfying, no one needs to stay up late at night pacing around the bedroom just to see that step-counter click over from 9,999 to 10,000,” said Scarlett Morris, PT, DPT, clinical assistant professor of physical therapy and rehabilitation science at the KU School of Health Professions.

The goal of 10,000 steps per day is often used in wearable fitness devices and smartphone apps, but the science behind that number is unclear. Meanwhile, a 2019 study published in the Journal of the American Medical Association (JAMA) found that although more steps taken per day were associated with lower mortality rates, those rates leveled off after 7,500 steps.

This is not to say that walking isn’t a great way to stay fit. It requires little equipment and can be easily worked into our daily routines. But staying active takes many forms, said Morris. “As we age, our bodies normally lose muscle mass at the rate of 3-8% each decade starting at age 30, so some form of weight training is also essential.”

And no, you don’t have to join a gym. Doing simple bodyweight exercises such chair squats or wall pushups is a great way to start.

“Some activity is better than none, and new research shows that even in smaller increments, benefits are present,” said Morris. “All activity or movement counts, whether it’s measured in steps, reps, or just by the way it makes us feel.”

MYTH 3: MOST WOMEN WITH BREAST CANCER HAVE A FAMILY HISTORY OF THE DISEASE.

Family history is associated with an increased risk of developing breast cancer, but most women who develop breast cancer do not have a family history of the disease, said Jennifer Klemp, Ph.D., MPH, professor of medicine in the Division of Clinical Oncology at the KU School of Medicine.

“Current estimates indicate that 70 to 80% of women with breast cancer have what is called sporadic breast cancer, meaning limited or no family history,” said Klemp.

Roughly 15-20% of women with breast cancer have close relatives who have been diagnosed with breast cancer. Five to 10% of women with breast cancer have actually inherited a specific alteration or mutation to a gene associated with breast cancer, such as the BRCA1 and BRCA2 genes.

Moreover, in addition to your family history of breast and other cancers such as ovarian, uterine, pancreatic, prostate, colon and melanoma, it’s important to understand how other factors such dense breasts, ethnic background or prior chest radiation can impact breast cancer risk.

“Women often overestimate their risk of developing breast cancer, both those with and without a family history,” said Klemp. If you have a family history of the disease, “talking with a provider who specializes in high risk patients is a good first step in understanding your cancer risk, screening and risk-reducing strategies, and whether genetic testing may be beneficial for you and your family.”

MYTH 4: READING IN THE DARK WILL DAMAGE YOUR EYES

If you were a kid who liked to read under the covers, chances are good that you heard about the dangers of reading in too-dim light.

It’s a misconception that Anjulie Quick, M.D., assistant professor in the Department of Ophthalmology at the KU School of Medicine, hears a lot, too.

“Luckily, there is no evidence to suggest that reading in the dark ― or reading without glasses, for that matter ― will damage your eyes,” said Quick. “However, it will cause strain on your eyes that can lead to eye fatigue and headaches.”

Even though they don’t lead to permanent eye damage, the strain and headaches are worth avoiding. Good lighting, angled properly, makes it easier to read without tiring out your eyes.

“A light over the shoulder can cause glare, making it more difficult to read,” advised Quick. “The best way to read is with a light directly shining on the page with your most current glasses, if prescribed. This will cause the least amount of strain on your eyes.”

MYTH 5: E-CIGARETTES AND OTHER VAPING DEVICES ARE NOT AS ADDICTIVE AS REGULAR CIGARETTES.

That’s exactly what the tobacco industry wants you to think, but these battery-powered devices are just the newest way to deliver nicotine, a substance as addictive as heroin and cocaine, to the body.

Instead of inhaling the nicotine-laden smoke created when a cigarette is lit, e-cigarette users inhale an aerosol created when the device heats a liquid that contains nicotine as well as other chemicals.

“The difference lies in how much nicotine is being delivered,” said Laura Martin, Ph.D., associate professor of population health at the KU School of Medicine. “A vaping device can contain as much nicotine as a pack of cigarettes.”

There’s no better customer than one addicted early and for life, which is why Big Tobacco has marketed these products largely to young people, creating kid-friendly flavorings for them such as gummi bear and cotton candy. One-third of U.S. high school students have tried vaping.

Young people are especially susceptible to nicotine’s addictive powers. Nicotine increases levels of the feel-good chemical dopamine in the brain.

“But the areas of the brain that help you control this reward response don’t fully develop until you are in your 20s,” said Martin. “So [when you vape] the reward systems are on overdrive, but the prefrontal systems that help you make decisions aren’t fully developed yet.”

Meanwhile, the more nicotine you use, the fewer dopamine receptors you have, which means you have to keep vaping more and more to keep those dopamine levels high.

And we already know the long-term effects of nicotine on the body: breathing problems, COPD (chronic obstructive pulmonary disease), lung cancer. Meanwhile, scientists don’t yet know all the harmful effects of the other chemicals in the vaping fluid.

Bottom line: vaping is a serious public threat and a way to create a new generation of nicotine addicts. Don’t fall for it.

MYTH 6: EATING LESS GLUTEN IS GOOD FOR EVERYONE.

A gluten-free diet is essential for the 1% of people who have been diagnosed with celiac disease, an autoimmune disorder in which the consumption of gluten — a protein in wheat, rye and barley — damages the lining of the small intestine and prevents the absorption of nutrients. Other people might avoid gluten because they have gastrointestinal symptoms and suspect they have a gluten sensitivity. If you think you might have one of these conditions, you should see your doctor for testing.

“But otherwise, avoiding gluten is probably more hassle than it’s worth,” said Heather Gibbs, Ph.D., RD, assistant professor of dietetics and nutrition at the KU School of Health Professions. “For one thing, it’s more expensive. But the biggest issue is the nutritional impact.”

As Gibb points out, research has shown that people following low or gluten-free diets eat fewer grains overall, choosing gluten-free products instead. Unfortunately, many products marketed as gluten-free are processed foods that are high in fat, and people following these diets often don’t consume enough B vitamins (thiamin, riboflavin, niacin and folate), iron and fiber. Without professional help, a gluten-restricted diet can lead to weight gain, poor gut health and nutrient deficiencies.

“If you need to follow a gluten-restricted diet, make an appointment with a registered dietitian (RD),” said Gibbs. “An RD is a licensed health professional who can help you navigate the diet’s challenges and devise a plan for meeting all your nutrient needs.”

MYTH 7: WE USE JUST 10% OF OUR BRAINS.

“Total bunk,” said Adam Parks, Ph.D., clinical assistant professor in the KU School of Medicine departments of Neurology and Psychiatry and Behavioral Sciences. “There’s a reason that the brain accounts for 3% of the body’s weight but uses 20% of its energy.”

The fact is, we don’t use all parts of our brains at every moment, but we use all parts of our brains throughout the course of every day. Different parts of the brain perform different tasks, and it’s the connections between those parts that are important to understand, said Parks.

“If you’re shooting a basketball, you are using different neural networks that are connected to each other,” said Parks. “The cerebellum and basil ganglia are important for motor processing and enable you to move and balance. But you also have to see that ball, so you’re also using parts of the brain that are connected to visual processing networks.”

Not only that, but thanks to functional magnetic resonance imaging, scientists know that during times when we think we aren’t doing anything at all, our brains are still at work.

“Default mode network ― that’s what our brains are doing when we aren’t performing a task,” said Parks. “And we’re pushing the 100% mark even then. Our brains are on when we are awake and when we are asleep.”